%%
@article{fds245763,
Author = {Chang, AM and Pritchard, DE},
Title = {Effects of interatomic attraction on total cross sections in
curve crossing collisions},
Journal = {The Journal of Chemical Physics},
Volume = {70},
Number = {10},
Pages = {4524-4533},
Publisher = {AIP Publishing},
Year = {1978},
Month = {January},
ISSN = {0021-9606},
url = {http://dx.doi.org/10.1063/1.437274},
Abstract = {We consider the influence of long range forces on the total
cross section for a two-state curve crossing process. If the
upper potential curve V 22(R) is attractive and behaves as R
-n for R beyond the crossing point, a centrifugal barrier
will arise which affects the cross section. Using the
Landau-Zener approximation, we derive cross sections
accounting for this which can be expressed in terms of a
simple dimensionless integral for both radial and rotational
coupling. Results for suitably reduced cross sections are
presented in a form which facilitates comparison with
experiments for n = 4, 5, and 6. Analytic expressions for
the threshold behavior are also presented. We show that the
low energy behavior of the cross section is very sensitive
to the type of coupling, the value of n, and the potential
at the crossing point. © 1979 American Institute of
Physics.},
Doi = {10.1063/1.437274},
Key = {fds245763}
}
@article{fds245762,
Author = {Chang, AM and Austin, RH},
Title = {Electron tunneling in cytochrome c},
Journal = {The Journal of Chemical Physics},
Volume = {77},
Number = {11},
Pages = {5272-5283},
Year = {1982},
Month = {January},
ISSN = {0021-9606},
url = {http://dx.doi.org/10.1063/1.443796},
Abstract = {An upper limit for the extinction coefficient of the charge
transfer band in the ferrohexacyanide-ferricytochrome c
redox couple has been determined from 800 to 1800 nm. We
obtain ε≤0.003 M-1 cm-1 between 800-1400 nm, ε≤0.02
M-1 cm-1 between 1400-1800 nm. Prompt transfer of charge due
to excitation in the heme absorption bands occurs with a
quantum yield of approximately 10-4. Simple vibronically
assisted tunneling theories and appropriate choice of highly
localized wave functions have been used to show that
tunneling theory can give a reasonable fit to all aspects of
charge transfer between cytochrome c and iron hexacyanide,
including the small value of the charge transfer band
extinction coefficient. © 1982 American Institute of
Physics.},
Doi = {10.1063/1.443796},
Key = {fds245762}
}
@article{fds245764,
Author = {Stormer, HL and Schlesinger, Z and Chang, A and Tsui, DC and Gossard,
AC and Wiegmann, W},
Title = {Energy structure and quantized hall effect of
two-dimensional holes},
Journal = {Physical Review Letters},
Volume = {51},
Number = {2},
Pages = {126-129},
Publisher = {American Physical Society (APS)},
Year = {1983},
Month = {January},
ISSN = {0031-9007},
url = {http://dx.doi.org/10.1103/PhysRevLett.51.126},
Abstract = {Combined magnetotransport and cyclotron-resonance
experiments in a two-dimensional hole system at a
modulation-doped GaAs-(AlGa)As heterojunction show that the
Kramers degeneracy of the lowest subband is lifted for
finite k giving rise to two cyclotron masses m1*=0.38m0 and
m2*=0.60m0 at EF=2.4 meV. The observation of plateaus in ρx
y shows that the quantized Hall effect is independent of the
details of the host band structure. © 1983 The American
Physical Society.},
Doi = {10.1103/PhysRevLett.51.126},
Key = {fds245764}
}
@article{fds245766,
Author = {Stormer, HL and Chang, A and Tsui, DC and Hwang, JCM and Gossard, AC and Wiegmann, W},
Title = {Fractional quantization of the hall effect},
Journal = {Physical Review Letters},
Volume = {50},
Number = {24},
Pages = {1953-1956},
Publisher = {American Physical Society (APS)},
Year = {1983},
Month = {January},
ISSN = {0031-9007},
url = {http://dx.doi.org/10.1103/PhysRevLett.50.1953},
Abstract = {Magnetotransport of two-dimensional electrons and holes was
studied in magnetic fields up to 300 kG and temperatures
down to 0.5 K. In addition to previously reported structures
at Landau-level filling factors =13 and 23, new structures
were resolved at =43, 53, 25, 35, 45, and 27. The results
suggest that fractional quantization of the Hall effect
exists in multiple series, each based on the inverse of an
odd integer. © 1983 The American Physical
Society.},
Doi = {10.1103/PhysRevLett.50.1953},
Key = {fds245766}
}
@article{fds318412,
Author = {Chang, AM and Paalanen, MA and Tsui, DC and Störmer, HL and Hwang,
JCM},
Title = {Fractional quantum Hall effect at low temperatures},
Journal = {Physical Review. B, Condensed Matter},
Volume = {28},
Number = {10},
Pages = {6133-6136},
Publisher = {American Physical Society (APS)},
Year = {1983},
Month = {January},
url = {http://dx.doi.org/10.1103/PhysRevB.28.6133},
Abstract = {We report a systematic study of the 23 fractional quantum
Hall effect at low temperatures (65-770 mK) for a
GaAs-AlxGa1-xAs sample of very high mobility (106 cm2/V
sec). We find the 23 Hall plateau to be accurately
quantized. The diagonal and Hall resistivities are observed
to be activated at each given filling factor ν=nheB around
23. The activation energy has a maximum value, Δmax, at
ν=23 and decreases to each side as ν moves away. By
varying the sample mobility and density simultaneously with
a backgate bias, we find Δmax strongly mobility and
magnetic field dependent. © 1983 The American Physical
Society.},
Doi = {10.1103/PhysRevB.28.6133},
Key = {fds318412}
}
@booklet{Chang84,
Author = {Chang, AM and Berglund, P and Tsui, DC and Stormer, HL and Hwang,
JCM},
Title = {Higher-order states in the multiple-series, fractional,
quantum hall effect},
Journal = {Physical Review Letters},
Volume = {53},
Number = {10},
Pages = {997-1000},
Publisher = {American Physical Society (APS)},
Year = {1984},
Month = {January},
ISSN = {0031-9007},
url = {http://dx.doi.org/10.1103/PhysRevLett.53.997},
Abstract = {We report results on the fractional quantum Hall effect in
GaAs-AlxGa1-xAs heterostructures at fractional Landau-level
filling factor 1/2=pq obtained with the combination of a
dilution refrigerator and the National Magnet Laboratory
hybrid magnet. We establish conclusively the quantiztation
of the higher-order states p in the series q. The Hall
resistance is accurately quantized to 2.3 parts in 104 for
the 25 state and 1.3 in 103 for the 35 state. New structures
are observed near 1/2=37, 47, 49, and 59. © 1984 The
American Physical Society.},
Doi = {10.1103/PhysRevLett.53.997},
Key = {Chang84}
}
@booklet{Chang84a,
Author = {Chang, AM and Paalanen, MA and Störmer, HL and Hwang, JCM and Tsui,
DC},
Title = {Fractional quantum hall effect at low temperatures},
Journal = {Surface Science},
Volume = {142},
Number = {1-3},
Pages = {173-178},
Publisher = {Elsevier BV},
Year = {1984},
Month = {July},
ISSN = {0039-6028},
url = {http://dx.doi.org/10.1016/0039-6028(84)90302-9},
Abstract = {We report results of low temperature (65 mK to 770 mK)
magneto-transport measurements of the 2 3 quantum Hall
plateau in an n-type GaAsAlxGa1-x As heterostructure. Both
the diagonal resistivity ρ{variant}xx and the deviation of
the Hall resistivity ρ{variant}xy, from the quantized value
show thermally activated behavior. The thermal activation
energy was measured as a function of the Landau level
filling factor, ν, at fixed magnetic fields, B, by varying
the density of the two-dimensional electrons with a
back-gate bias. The activation energy Δ of ρ{variant}xx is
maximum at the center of the Hall plateau, when ν = 2 3,
and decreases on either side of it, as ν moves away from 2
3. This resonance-like dependence on ν is characterized by
a maximum activation energy, Δm = 830 mK and Δν ν = 8%
at B = 92.5 kG. In addition, we have verified that the Hall
conductance is quantized to ( 2 3) e2 h to an accuracy of 3
parts in 104. The I-V relation is linear down to an electric
field of less than 10 -5 V cm, indicating that the current
carrying state is not pinned. © 1984.},
Doi = {10.1016/0039-6028(84)90302-9},
Key = {Chang84a}
}
@article{fds245754,
Author = {Chang, AM},
Title = {Fractional Quantum Hall Effect},
Booktitle = {Festkorper Probleme XXV (Advances in Solid State
Physics)},
Publisher = {Vieweg},
Editor = {Grosse, P},
Year = {1985},
Key = {fds245754}
}
@article{fds245757,
Author = {Austin, RH and Gerstman, B and Chang, AM and Rokshar,
D},
Title = {Introduction to Tunneling in Biology},
Journal = {Comments on Molecular and Cellular Biology},
Volume = {2},
Number = {295},
Year = {1985},
Key = {fds245757}
}
@booklet{Chang85,
Author = {Chang, AM and Tsui, DC},
Title = {Experimental observation of a striking similarity between
quantum hall transport coefficients},
Journal = {Solid State Communications},
Volume = {56},
Number = {1},
Pages = {153-154},
Publisher = {Elsevier BV},
Year = {1985},
Month = {January},
ISSN = {0038-1098},
url = {http://dx.doi.org/10.1016/0038-1098(85)90555-1},
Abstract = {The derivative of the Quantum Hall resistance, ρxy, with
respect to the carrier density, n, has been measured for a
two-dimensional electron gas in a GaAs-AlxGa1-xAs
heterostructure, as a function of magnetic field. dρxy/dn
exhibits a remarkable similarity to the diagonal
resistivity, ρxy, to the extent that one is almost directly
proportional to the other. Our result suggests the
possibility of a fundamental connection between the two
quantities. © 1985.},
Doi = {10.1016/0038-1098(85)90555-1},
Key = {Chang85}
}
@booklet{Zheng85,
Author = {Zheng, HZ and Tsui, DC and Chang, AM},
Title = {Distribution of the quantized Hall potential in
GaAs-AlxGa1-xAs heterostructures},
Journal = {Physical Review. B, Condensed Matter},
Volume = {32},
Number = {8},
Pages = {5506-5509},
Publisher = {American Physical Society (APS)},
Year = {1985},
Month = {January},
ISSN = {0163-1829},
url = {http://dx.doi.org/10.1103/PhysRevB.32.5506},
Abstract = {We report measurements of the Hall potential distribution in
the interior of the two-dimensional electron gas in
GaAs-AlxGa1-xAs heterostructures. In the quantized Hall
regime, our data provide direct evidence for the existence
of extended states in the bulk of a two-dimensional system.
Bunching of the potential distribution is observed as a
function of the quantizing magnetic field and is attributed
to the presence of density gradients as the dominant
macroscopic inhomogeneities. © 1985 The American Physical
Society.},
Doi = {10.1103/PhysRevB.32.5506},
Key = {Zheng85}
}
@booklet{Wei85,
Author = {Wei, HP and Chang, AM and Tsui, DC and Razeghi, M},
Title = {Temperature dependence of the quantized Hall
effect},
Journal = {Physical Review. B, Condensed Matter},
Volume = {32},
Number = {10},
Pages = {7016-7019},
Publisher = {American Physical Society (APS)},
Year = {1985},
Month = {January},
ISSN = {0163-1829},
url = {http://dx.doi.org/10.1103/PhysRevB.32.7016},
Abstract = {We reported detailed measurements of the temperature
dependence of the quantized Hall effect from 4.2 to 50 K in
the i=2 plateau region in InGaAs-InP. We deduce from the
data that there is a significant density of localized states
between the two Landau levels, with a value of 1×1010 cm-2
meV-1 at the middle of the mobility gap. We also found that
the correlations between xx and xy show the trend predicted
by the recent two-parameter scaling theory of localization
in quantized Hall effect. © 1985 The American Physical
Society.},
Doi = {10.1103/PhysRevB.32.7016},
Key = {Wei85}
}
@booklet{Boebinger85,
Author = {Boebinger, GS and Chang, AM and Stormer, HL and Tsui,
DC},
Title = {Magnetic field dependence of activation energies in the
fractional quantum hall effect},
Journal = {Physical Review Letters},
Volume = {55},
Number = {15},
Pages = {1606-1609},
Publisher = {American Physical Society (APS)},
Year = {1985},
Month = {January},
ISSN = {0031-9007},
url = {http://dx.doi.org/10.1103/PhysRevLett.55.1606},
Abstract = {We have studied the temperature dependence of the fractional
quantum Hall effect at Landaulevel filling factors =13, 23,
43, 53, 25, and 35 in magnetic fields up to 28 T to
determine the magnitude of the associated energy gaps. The
data suggest a single activation energy for =13, 23, 43, and
35. Its magnitude, much smaller than predicted by current
theories, vanishes for B6 T and saturates at B18 T. The data
also suggest a single activation energy for =25 and 35 which
is smaller than predicted. © 1985 The American Physical
Society.},
Doi = {10.1103/PhysRevLett.55.1606},
Key = {Boebinger85}
}
@booklet{Boebinger85a,
Author = {Boebinger, GS and Chang, AM and Stormer, HL and Tsui,
DD},
Title = {Competition between neighboring minima in the fractional
quantum Hall effect},
Journal = {Physical Review. B, Condensed Matter},
Volume = {32},
Number = {6},
Pages = {4268-4271},
Publisher = {American Physical Society (APS)},
Year = {1985},
Month = {January},
ISSN = {0163-1829},
url = {http://dx.doi.org/10.1103/PhysRevB.32.4268},
Abstract = {We report observations of a temperature-dependent
competition in the fractional quantum Hall effect in
GaAs/AlGaAs heterostructures. Two pairs of neighboring
minima in the diagonal resistance xx versus magnetic field
exhibit a competition by which the stronger minimum engulfs
the weaker minimum as the temperature is decreased. This
competition is observed at fractional Landau filling factor
between the minima at =(7/5) and (4/3), and the minima at
=(8/5) and 3. The strength of the minima at =(4/3) and (5/3)
relative to one another contrasts with the strength of the
=(1/3) and (2/3) minima. © 1985 The American Physical
Society.},
Doi = {10.1103/PhysRevB.32.4268},
Key = {Boebinger85a}
}
@article{fds245767,
Author = {Stoermer, HL and Chang, AM and Tsui, DC and Hwang,
JCM},
Title = {BREAKDOWN OF THE INTEGRAL QUANTUM HALL EFFECT.},
Pages = {267-270},
Year = {1985},
Month = {December},
ISBN = {0387961089},
Abstract = {We report experimental results on the breakdown of the
low-dissipation currents in the integral quantum Hall effect
at temperatures from 6 to 0. 5K, and in magnetic fields up
to 28T using Corbino-ring geometry. The Hall current at
which the abrupt breakdown occurs is the same for the center
of the i equals 1, 2, and 4 resistance minima. The critical
current decreases rapidly away from this central position.
We discuss three possible models to explain our
observations.},
Key = {fds245767}
}
@booklet{Wei86,
Author = {Wei, HP and Chang, AM and Tsui, DC and Pruisken, AMM and Razeghi,
M},
Title = {An experimental test of two-parameter scaling of integral
quantum Hall effect},
Journal = {Surface Science},
Volume = {170},
Number = {1-2},
Pages = {238-242},
Publisher = {Elsevier BV},
Year = {1986},
Month = {April},
ISSN = {0039-6028},
url = {http://dx.doi.org/10.1016/0039-6028(86)90968-4},
Abstract = {Detailed measurements are made of the temperature and
magnetic field dependences of the magneto-transport
coefficients, σxx and σxy, in an In0.53Ga0.47AsInP
heterostructure to test the (two-parameter) renormalization
group theory of the integral quantum Hall effect. ©
1986.},
Doi = {10.1016/0039-6028(86)90968-4},
Key = {Wei86}
}
@booklet{Boebinger86,
Author = {Boebinger, GS and Chang, AM and Störmer, HL and Tsui, DC and Hwang,
JCM and Cho, A and Tu, C and Weimann, G},
Title = {Activation energies of fundamental and higher order states
in the fractional quantum Hall effect},
Journal = {Surface Science},
Volume = {170},
Number = {1-2},
Pages = {129-135},
Publisher = {Elsevier BV},
Year = {1986},
Month = {April},
ISSN = {0039-6028},
url = {http://dx.doi.org/10.1016/0039-6028(86)90951-9},
Abstract = {We report a systematic study of activation energies for the
fundamental states in the fractional quantum Hall effect at
Landau level filling factors v = 1 3, 2 3, and 5 3 in
magnetic fields to 28 T. We also present activation energies
for the higher order states at v = 2 5 and 3 5. ©
1986.},
Doi = {10.1016/0039-6028(86)90951-9},
Key = {Boebinger86}
}
@booklet{Tsang86,
Author = {Tsang, WT and Chang, AM and Ditzenberger, JA and Tabatabaie,
N},
Title = {Two-dimensional electron gas in a Ga0.47In0.53As/InP
heterojunction grown by chemical beam epitaxy},
Journal = {Applied Physics Letters},
Volume = {49},
Number = {15},
Pages = {960-962},
Publisher = {AIP Publishing},
Year = {1986},
Month = {December},
ISSN = {0003-6951},
url = {http://dx.doi.org/10.1063/1.97495},
Abstract = {Shubnikov-de Haas, quantum Hall effect, and cyclotron
resonance measurements revealed the existence of a high
mobility, two-dimensional electron gas at the
Ga0.47In0.53As/InP heterointerface grown by chemical beam
epitaxy. Enhanced electron mobilities were as high as
∼130×103 cm2/V s at 4.2 K. A striking feature in the data
which also indicates that the sample is of high quality is
the large number of Shubnikov-de Haas oscillation periods
observed. Oscillations were observable up to a Landau
filling factor of around 50, corresponding to a Landau level
index of 25.},
Doi = {10.1063/1.97495},
Key = {Tsang86}
}
@article{fds245750,
Author = {Chang, AM},
Title = {The Fractional Quantum Hall Effect: Experimental
Aspects},
Booktitle = {THE QUANTUM HALL EFFECT},
Publisher = {Springer-Verlag},
Editor = {Prange, RE and Girvin, SM},
Year = {1987},
Key = {fds245750}
}
@booklet{Timp87a,
Author = {Timp, G and Chang, AM and Cunningham, JE and Chang, TY and Mankiewich,
P and Behringer, R and Howard, RE},
Title = {Observation of the Aharonov-Bohm effect for
c>1},
Journal = {Physical Review Letters},
Volume = {58},
Number = {26},
Pages = {2814-2817},
Publisher = {American Physical Society (APS)},
Year = {1987},
Month = {January},
ISSN = {0031-9007},
url = {http://dx.doi.org/10.1103/PhysRevLett.58.2814},
Abstract = {We have observed the Aharonov-Bohm effect in the
magnetoresistance of doubly connected geometries fabricated
in high-mobility GaAs/AlGaAs heterostructures. Periodic
oscillations in the resistance associated with the fluxs
penetrating the annulus are suppressed above c5, where c is
the cyclotron frequency and is the scattering time, while
fluctuations in the resistance as a function of magnetic
field are observed for 0<c<300, superimposed upon
Shubnikov-deHaas oscillations. © 1987 The American Physical
Society.},
Doi = {10.1103/PhysRevLett.58.2814},
Key = {Timp87a}
}
@booklet{Devegvar87,
Author = {Vegvar, PGND and Chang, AM and Timp, G and Mankiewich, PM and Cunningham, JE and Behringer, R and Howard, RE},
Title = {Critical currents of the quantum Hall effect in the
mesoscopic regime},
Journal = {Physical Review. B, Condensed Matter},
Volume = {36},
Number = {17},
Pages = {9366-9369},
Publisher = {American Physical Society (APS)},
Year = {1987},
Month = {January},
ISSN = {0163-1829},
url = {http://dx.doi.org/10.1103/PhysRevB.36.9366},
Abstract = {The critical currents associated with the breakdown of the
quantum Hall effect have been measured in high-mobility,
one-dimensional channels fabricated in GaAs-AlxGa1-xAs
heterostructures. The results differ in several respects
from the breakdown in macroscopic samples. The on-set of
dissipation shows little hysteresis and depends on the
direction of the current with respect to the magnetic field.
The value of the critical current is also independent of the
filling factor across a large fraction of the Hall plateau.
These observations indicate that mesoscopic considerations
must be included in any theory of breakdown on this size
scale. © 1987 The American Physical Society.},
Doi = {10.1103/PhysRevB.36.9366},
Key = {Devegvar87}
}
@booklet{Timp87,
Author = {Timp, G and Chang, AM and Mankiewich, P and Behringer, R and Cunningham,
JE and Chang, TY and Howard, RE},
Title = {Quantum transport in an electron-wave guide},
Journal = {Physical Review Letters},
Volume = {59},
Number = {6},
Pages = {732-735},
Publisher = {American Physical Society (APS)},
Year = {1987},
Month = {January},
ISSN = {0031-9007},
url = {http://dx.doi.org/10.1103/PhysRevLett.59.732},
Abstract = {We have fabricated high-mobility, one dimensional wires in
GaAs-AlGaAs heterostructures and measured the resistance as
a function of magnetic field and temperature. Because of the
size of the devices and the high mobility, only a few
channels carry the current at 35 mK with minimal scattering.
Fluctuations in the resistance as a function of magnetic
field due to quantum interference are observed for 0<c<300,
where c is the cyclotron frequency and is the scattering
time, superimposed upon Shubnikov "de Haas oscillations and
the Hall effect. © 1987 The American Physical
Society.},
Doi = {10.1103/PhysRevLett.59.732},
Key = {Timp87}
}
@booklet{Boebinger87,
Author = {Boebinger, GS and Stormer, HL and Tsui, DC and Chang, AM and Hwang, JCM and Cho, AY and Tu, CW and Weimann, G},
Title = {Activation energies and localization in the fractional
quantum Hall effect},
Journal = {Physical Review. B, Condensed Matter},
Volume = {36},
Number = {15},
Pages = {7919-7929},
Publisher = {American Physical Society (APS)},
Year = {1987},
Month = {January},
ISSN = {0163-1829},
url = {http://dx.doi.org/10.1103/PhysRevB.36.7919},
Abstract = {This paper summarizes an extensive study of the temperature
dependence of magnetotransport in the fractional quantum
Hall effect in GaAs-AlxGa1-xAs heterostructure devices of
varying mobility and density. For devices with electron
mobility 400 000 1 000 000 cm2/V s, we find a single
activation energy, /23, in the longitudinal transport
coefficients, xx and xx, for Landau-level filling
factors=(1/3, (2/3, (4/3, and (5/3, with a magnetic field
dependence which is vanishingly small for B 5.5 T and
increases to 63.8 K at B=30 T. The observed 3 is smaller by
more than a factor of 3 than either the unbound
quasiparticle-quasihole pair-creation energy gap or the
magneto-roton energy gap, calculated for an ideal
two-dimensional electron system. Observations for devices of
mobility 0 300 000 cm2/V s yield even smaller 3. Adequate
fitting of all our results requires inclusion of finite
electron layer thickness and disorder, with the effect of
decreasing the energy gaps and providing a finite magnetic
field threshold. At low temperatures and high magnetic
fields, deviations from activated conduction are observed.
These deviations are attributed to two-dimensional hopping
conduction in a magnetic field. Samples of sufficiently low
mobility, 0150 000 cm2/V s exhibit no evidence of activated
conduction. Rather, the transport is qualitatively
consistent with two-dimensional hopping alone. Studies at
Landau-level filling factors =(2/5 and (3/5 also yield a
single activation energy, /25, with a weak magnetic field
dependence. Experimentally, we find 35 0.4, compared with an
expected ratio of 0.28 from simple theoretical
considerations. © 1987 The American Physical
Society.},
Doi = {10.1103/PhysRevB.36.7919},
Key = {Boebinger87}
}
@booklet{Mankiewich88,
Author = {Mankiewich, PM and Behringer, RE and Howard, RE and Chang, AM and Chang,
TY and Chelluri, B and Cunningham, J and Timp, G},
Title = {Observation of aharonov-bohm effect in quasi-one-dimensional
gaas/algaas rings},
Journal = {J. Vacuum Sci. & Tech. B},
Volume = {6},
Number = {1},
Pages = {131-133},
Year = {1988},
Key = {Mankiewich88}
}
@booklet{Chang88a,
Author = {Chang, AM and Timp, G and Howard, RE and Behringer, RE and Mankeiwich,
PM and Cunningham, JE and Chang, TY and Chelluri,
B},
Title = {Quantum transport in quasi-one-dimensional
GaAsAlxGa1-xAs heterostructure
devices},
Journal = {Superlattices and Microstructures},
Volume = {4},
Number = {4-5},
Pages = {515-520},
Publisher = {Elsevier BV},
Year = {1988},
Month = {January},
ISSN = {0749-6036},
url = {http://dx.doi.org/10.1016/0749-6036(88)90229-7},
Abstract = {We study quantum transport properties of narrow
GaAsAlxGa1-xAs wires and rings made by electron beam
lithography. At low temperatures, clear signatures of
Ah́aronov-Bohm quantum interference effects are observed
due to the application of a perpendicular magnetic field.
The ring devices show large amplitude (-5%) resistance
oscillations periodic in magnetic flux penetrating the ring,
which diminish in amplitude above -3kG. The wire devices
show aperiodic resistance fluctuations as large as 100%,
which persist into the quantum Hall regime. The large
amplitudes observed result from the small number of
transverse channels occupied below the Fermi level. ©
1988.},
Doi = {10.1016/0749-6036(88)90229-7},
Key = {Chang88a}
}
@booklet{Timp88,
Author = {Timp, G and Chang, AM and DeVegvar, P and Howard, RE and Behringer, R and Cunningham, JE and Mankiewich, P},
Title = {Quantum transport in one-dimensional GaAs/AlGaAs
microstructures},
Journal = {Surface Science},
Volume = {196},
Number = {1-3},
Pages = {68-78},
Publisher = {Elsevier BV},
Year = {1988},
Month = {January},
ISSN = {0039-6028},
url = {http://dx.doi.org/10.1016/0039-6028(88)90666-8},
Abstract = {We have observed the Aharonov-Bohm effect in the
magnetoresistance of doubly connected geometries fabricated
in high mobility GaAs/AlGaAs heterostructures. Periodic
oscillations in the resistance associated with the magnetic
fluxes θ0 = hc/e, θ0/2, and θ0/3 penetrating the annulus
are suppressed for fields above √hc/eH ≈ W/2 where W is
the width of the wire comprising the annulus, corresponding
to ωc⊥ >1 where ωc is the cyclotron frequency and ⊥
ist the scattering time. Correlated fluctuations in the
resistance as a function of magnetic field associated with
the flux penetrating the wires comprising the annuli are
observed for 0<ωc⊥<300, concomitantly with Shubnikov-de
Haas oscillations and the Hall effect. ©
1987.},
Doi = {10.1016/0039-6028(88)90666-8},
Key = {Timp88}
}
@booklet{Chang88b,
Author = {Chang, AM and Timp, G and Chang, TY and Cunningham, JE and Mankiewich,
PM and Behringer, RE and Howard, RE},
Title = {Deviation of the quantum hall effect from exact quantization
in narrow GaAs-AlxGa1-xAs
heterostructure devices},
Journal = {Solid State Communications},
Volume = {67},
Number = {8},
Pages = {769-772},
Publisher = {Elsevier BV},
Year = {1988},
Month = {January},
ISSN = {0038-1098},
url = {http://dx.doi.org/10.1016/0038-1098(88)90021-X},
Abstract = {We report the first observation of deviaton of the i=4
quantum Hall plateau from its quantized value, in narrow
GaAs-AlxGa1-xAs quasi-1-d wires of width 2000A. The
deviation arises in the form of aperiodic fluctuations as
the magnetic field is varied, even though a deep minimum
developes in longitudinal resistance. The fluctuation size
grows with decreasing temperature and can be as large as
250Ω at 50mK. We suggest the observations arise from a
combination of localization and Aharonov-Bohm quantum
interference effects. © 1988.},
Doi = {10.1016/0038-1098(88)90021-X},
Key = {Chang88b}
}
@booklet{Cunningham88,
Author = {Cunningham, JE and Tsang, WT and Timp, G and Schubert, EF and Chang, AM and Owusu-Sekyere, K},
Title = {Quantum size effect in monolayer-doped heterostructures},
Journal = {Physical Review. B, Condensed Matter},
Volume = {37},
Number = {8},
Pages = {4317-4320},
Publisher = {American Physical Society (APS)},
Year = {1988},
Month = {January},
ISSN = {0163-1829},
url = {http://dx.doi.org/10.1103/PhysRevB.37.4317},
Abstract = {We report molecular-beam-epitaxial growth of a new structure
formed by monolayer doping the barrier of an AlxGa1-xAs-GaAs
heterojunction. Our investigations of these structures
include the quantum Hall effect and variable temperature
mobility measurements, which reveal enhancements in
interface densities are achievable along with very high
mobility. © 1988 The American Physical Society.},
Doi = {10.1103/PhysRevB.37.4317},
Key = {Cunningham88}
}
@booklet{Chang88c,
Author = {Chang, AM and Timp, G and Chang, TY and Cunningham, JE and Chelluri, B and Mankiewich, PM and Behringer, RE and Howard, RE},
Title = {Magneto-quantum transport in a quasi-one-dimensional
GaAs/AlxGa1-xAs ring},
Journal = {Surface Science},
Volume = {196},
Number = {1-3},
Pages = {46-51},
Publisher = {Elsevier BV},
Year = {1988},
Month = {January},
ISSN = {0039-6028},
url = {http://dx.doi.org/10.1016/0039-6028(88)90663-2},
Abstract = {We study the magneto-transport properties of a quasi-ID
GaAs/AlxGa1-xAs ring of mobility 40 000 cm2/V·a at 4 K. The
inelastic scattering length is about 4000 Å while the
sample length is of the order of 3 μm, so that we are in
the diffusive regime. A variety of quantum interference
phenomena are observed, including negative
magneto-resistance, hole Aharonov-Bohm effect, and
aperiodic/quasiperiodic resistance fluctuations. This rich
variety enables us to estimate the sample conducting width
and electron phase coherence length, lθ, so that we may
attempt to obtain a consistent picture of these related
phenomena. In addition, we obtain a magnetic field scale on
which the hole oscillations disappear. ©
1987.},
Doi = {10.1016/0039-6028(88)90663-2},
Key = {Chang88c}
}
@booklet{Chang88,
Author = {Chang, AM and Owusu-Sekyere, K and Chang, TY},
Title = {Observation of phase-shift locking of the Aharonov-Bohm
effect in doubly connected GaAsAlxGa1-xAs
heterostructure devices},
Journal = {Solid State Communications},
Volume = {67},
Number = {11},
Pages = {1027-1030},
Publisher = {Elsevier BV},
Year = {1988},
Month = {January},
ISSN = {0038-1098},
url = {http://dx.doi.org/10.1016/0038-1098(88)91179-9},
Abstract = {We have observed a tendency toward locking of the
Aharonov-Bohm effect phase shift, in doubly connected,
quasi-one-dimensional GaAsAlxGa1-xAs devices. The
resistances of adjacent segments within a device exhibit
periodic modulations, due to magnetic flux penetrating the
area enclosed by the doubly connected geometry, which are
phase-shifted from each other by a value of close to 180°.
This phase shift value persists over a range of 200 periods
(∼4kGauss in magnetic field), and is observed for various
current-voltage configurations. © 1988.},
Doi = {10.1016/0038-1098(88)91179-9},
Key = {Chang88}
}
@booklet{Chang88d,
Author = {Chang, AM and Timp, G and Cunningham, JE and Mankiewich, PM and Behringer, RE and Howard, RE and Baranger, HU},
Title = {Real-space and magnetic-field correlation of
quantum-resistance fluctuations in the ballistic regime in
narrow GaAs-AlxGa},
Journal = {Physical Review. B, Condensed Matter},
Volume = {37},
Number = {5},
Pages = {2745-2748},
Year = {1988},
Month = {February},
ISSN = {0163-1829},
url = {http://www.ncbi.nlm.nih.gov/pubmed/9944842},
Doi = {10.1103/physrevb.37.2745},
Key = {Chang88d}
}
@booklet{Owususekyere88,
Author = {Owusu-Sekyere, K and Chang, AM and Chang, TY},
Title = {Fabrication of gatable submicron channels in
AlxGa 1-xAs-GaAs heterostructures},
Journal = {Applied Physics Letters},
Volume = {52},
Number = {15},
Pages = {1246-1248},
Publisher = {AIP Publishing},
Year = {1988},
Month = {December},
ISSN = {0003-6951},
url = {http://dx.doi.org/10.1063/1.99170},
Abstract = {A new, simplified process has been developed for fabricating
submicron AlxGa1-xAs-GaAs heterostructure devices for
low-temperature transport studies, with the advantage of
gatability. This process utilizes electron beam lithography,
photolithography, and wet etching techniques to laterally
confine the two-dimensional electron gas, and possesses the
unique feature that the metal etch mask for the electron
beam defined narrow section is deposited directly on top of
the heterostructure surface, allowing for use as a gate.
Devices of lithographic widths from 0.4 to 2.0 μm have been
successfully fabricated, where the 0.4 μm devices of both
enhancement and depletion modes have been demonstrated to
function down to 0.35 K in temperature.},
Doi = {10.1063/1.99170},
Key = {Owususekyere88}
}
@article{chang:2695,
Author = {Chang, AM and Chang, TY and Baranger, HU},
Title = {Erratum: Quenching of the Hall resistance in a novel
geometry [Phys. Rev. Lett. [bold 63], 996
(1989)]},
Journal = {Phys. Rev. Lett.},
Volume = {63},
Number = {24},
Pages = {2695-2695},
Publisher = {APS},
Year = {1989},
ISSN = {0031-9007},
url = {http://link.aps.org/abstract/PRL/v63/p2695/s4},
Doi = {10.1103/PhysRevLett.63.2695.4},
Key = {chang:2695}
}
@article{fds245770,
Author = {Chang, AM and Cunningham, JE},
Title = {Transmission and reflection probabilities between ν=1 and
ν= 2 3 quantum Hall effects and between ν= 2 3 and ν= 1 3
effects},
Journal = {Solid State Communications},
Volume = {72},
Number = {7},
Pages = {651-655},
Year = {1989},
Month = {January},
ISSN = {0038-1098},
url = {http://dx.doi.org/10.1016/0038-1098(89)90666-2},
Abstract = {We perform transport experiments in the quantum Hall regime
on transmission through a barrier region exhibiting a
fractional quantum Hall effect. For transmission from the
ν=1 effect through a barrier at the 2 3 effect, the
transmission probability is 2 3(0.998±.005) and the
reflection is 1 3(.983±.010). Interpreted in terms of
conduction via edge states, our results yield a
quasi-particle charge of -e 3±2% in the 2 3 effect in one
picture, and a reduction in the single-particle density of
states in another. Data on transmission from the 2 3 effect
through a barrier at 1 3 are consistent with these
interpretations. © 1989.},
Doi = {10.1016/0038-1098(89)90666-2},
Key = {fds245770}
}
@article{fds304529,
Author = {Chang, AM and Chang, TY and Baranger, HU},
Title = {Erratum: Quenching of the Hall resistance in a novel
geometry (Physical Review Letters (1989) 63, 996
(2695))},
Journal = {Physical Review Letters},
Volume = {63},
Number = {24},
Pages = {2695},
Publisher = {American Physical Society (APS)},
Year = {1989},
Month = {January},
ISSN = {0031-9007},
url = {http://dx.doi.org/10.1103/PhysRevLett.63.2695.4},
Doi = {10.1103/PhysRevLett.63.2695.4},
Key = {fds304529}
}
@article{fds245769,
Author = {Cunningham, JE and Timp, G and Chang, AM and Chiu, TH and Jan, W and Schubert, EF and Tsung, WT},
Title = {Spatial localization of Si in selectively δ-doped
AlxGa1-xAs/GaAs heterostructures for
high mobility and density realization},
Journal = {Journal of Crystal Growth},
Volume = {95},
Number = {1-4},
Pages = {253-256},
Year = {1989},
Month = {February},
ISSN = {0022-0248},
url = {http://dx.doi.org/10.1016/0022-0248(89)90395-3},
Abstract = {We report on a new type of structure formed by δ-doping the
barrier of an AlxGa1-xAs/GaAs heterostructure. We
investigate transport in these structures which reveal that
very high quality fractional quantum hall structure occurs
as well as systematically high density and mobility
(2.2×106 cm2/V·s). The dependence of mobility and density
on spacer layer thickness is explored. We show that the
observed improvements in 2DEG properties are expected from
the spatial localization of the Si dopant. ©
1989.},
Doi = {10.1016/0022-0248(89)90395-3},
Key = {fds245769}
}
@article{fds245788,
Author = {Chang, AM and Chang, TY and Baranger, HU},
Title = {Quenching of the Hall resistance in a novel
geometry.},
Journal = {Physical Review Letters},
Volume = {63},
Number = {9},
Pages = {996-999},
Year = {1989},
Month = {August},
url = {http://www.ncbi.nlm.nih.gov/pubmed/10041242},
Doi = {10.1103/physrevlett.63.996},
Key = {fds245788}
}
@article{fds245773,
Author = {Chang, AM},
Title = {A unified transport theory for the integral and fractional
quantum hall effects: Phase boundaries, edge currents, and
transmission/reflection probabilities},
Journal = {Solid State Communications},
Volume = {74},
Number = {9},
Pages = {871-876},
Year = {1990},
Month = {January},
ISSN = {0038-1098},
url = {http://dx.doi.org/10.1016/0038-1098(90)90447-J},
Abstract = {We propose a unified transport theory for the fractional
(FQHE) and integral quantum Hall effect (IQHE) of the
Buttiker-Landauer type in the presence of smooth confinement
and impurity potentials, where resistances are expressed in
terms of transmission and reflection probabilities of edge
channels in the incompressible fluid states.
Electron-electron interaction is taken into account in the
FQHE by writing down a Laughlin type wave function for a
pure phase, and in the compressible fluids at non-special
filling factors by a self-consistent screening of the
background potential. Our theory is able to explain recent
experimental observations. © 1990.},
Doi = {10.1016/0038-1098(90)90447-J},
Key = {fds245773}
}
@article{fds245771,
Author = {Chang, AM and Cunningham, JE},
Title = {Transmission and reflection probabilities between the ν=1
and the ν= 2 3 quantum hall effects},
Journal = {Surface Science},
Volume = {229},
Number = {1-3},
Pages = {216-218},
Year = {1990},
Month = {April},
ISSN = {0039-6028},
url = {http://dx.doi.org/10.1016/0039-6028(90)90874-8},
Abstract = {We report a transport experiment in the quantum Hall regime
on the transmission of electron waves from a region
exhibiting the ν=1 integral quantum Hall effect, through a
barrier region exhibiting the ν= 2 3 fractional quantum
Hall effect. Our work represents the first transport study
across an interface between an integral and a fractional
quantum Hall effect. We analyze our data in terms of the
Büttiker-Landauer formalism and conduction via Landau edge
states. We find a transmission probability of 2 3 (0.999 ±
0.002) and a reflection probability of 1 3 (0.995 ± 0.003).
These results can be interpreted in two ways: (1) they yield
a quasi-particle charge of ( -e 3) ± 0.5% in the 2 3
effect, and (2) the single-particle electronic density of
states is reduced to 2 3 the value for a non-interacting
electron system. © 1990.},
Doi = {10.1016/0039-6028(90)90874-8},
Key = {fds245771}
}
@article{fds245774,
Author = {Chang, AM and Chang, TY},
Title = {Quenching of the Hall effect in a novel geometry},
Journal = {Surface Science},
Volume = {229},
Number = {1-3},
Pages = {209-211},
Publisher = {Elsevier BV},
Year = {1990},
Month = {April},
ISSN = {0039-6028},
url = {http://dx.doi.org/10.1016/0039-6028(90)90872-6},
Abstract = {We study the Hall effect at low magnetic fields in ballistic
GaAs-AlxGa1 - xAs heterostructure Hall junctions that
contain four, three, two, or one narrow constrictions in the
junction region. These geometries are investigated to
determine the necessary condition for observation of the
quenching of the Hall effect. We find that only the four
constriction geometry shows a genuine quenching. By applying
a backgate bias, quenching is produced within a finite
electron density range. Our results are interpreted within
the framework of the Büttiker-Landauer formulas in terms of
junction scattering of the electrons. ©
1990.},
Doi = {10.1016/0039-6028(90)90872-6},
Key = {fds245774}
}
@article{fds245751,
Author = {Chang, AM},
Title = {The Hall Effect in Quantum Wires},
Volume = {4},
Booktitle = {Electronic Structure and Properties of Semiconductors},
Publisher = {VCH Verlagsgesellshaft},
Editor = {Schroter, W},
Year = {1991},
Key = {fds245751}
}
@article{fds245755,
Author = {CHANG, AM},
Title = {QUENCHING OF THE HALL RESISTANCE IN A NOVEL
GEOMETRY},
Journal = {Modern Physics Letters B},
Volume = {05},
Number = {01},
Pages = {21-37},
Publisher = {World Scientific Pub Co Pte Lt},
Year = {1991},
Month = {January},
ISSN = {0217-9849},
url = {http://dx.doi.org/10.1142/s0217984991000046},
Abstract = {<jats:p> We review experiments on the observation of Hall
resistance anomalies in ballistic Hall junctions of novel
geometries, in submicron GaAs-Al <jats:sub>x</jats:sub> Ga
<jats:sub>1−</jats:sub><jats:sub>x</jats:sub> As
heterostructure devices. We demonstrate that the low
magnetic field Hall resistance is greatly influenced by the
junction geometry, and that particular geometries are
required to give rise to a phenomenon known as
“quenching” of the Hall resistance where the
conventional linear Hall resistance is suppressed to nearly
zero, and to a related plateau feature at slightly higher
magnetic fields, known as the “last plateau.” These
anomalies are explained in terms of the collimation of
ballistic electron beams by specific geometric structures
and the scattering properties of the Hall junction side
walls. </jats:p>},
Doi = {10.1142/s0217984991000046},
Key = {fds245755}
}
@article{fds245772,
Author = {Chin, A and Chang, TY and Ourmazd, A and Monberg, EM and Chang, AM and Kurdak, C},
Title = {Effects of substrate orientation, pseudomorphic growth and
superlattice on alloy scattering in modulation doped
GaInAs},
Journal = {Journal of Crystal Growth},
Volume = {111},
Number = {1-4},
Pages = {466-469},
Year = {1991},
Month = {May},
ISSN = {0022-0248},
url = {http://dx.doi.org/10.1016/0022-0248(91)91021-2},
Abstract = {The possibility of reducing alloy scattering in MBE
Ga1-xInxAs has been studied experimentally by growing
modulation doped heterostructures (A) with an InAs/GaInAs
superlattice 2DEG channel, (B) on a vicinal (110) InP
substrate, and (C) with a strain compensated pseudomorphic
channel. The maximum 77 K mobility obtained in each case is
(A) 60,600, (B) 69,300, and (C) 123,100 cm2/V⋯s, using
x=0.50, 0.53, and 0.80, respectively. Partial alloy ordering
is observed in case (B). Cyclotron resonance measurements
indicate that the reduction of m* contributes much less to
the enhancement of mobility in case (C) than the alloy
composition factor x(1-x). Alloy ordering may also be
important. © 1991.},
Doi = {10.1016/0022-0248(91)91021-2},
Key = {fds245772}
}
@article{fds245756,
Author = {Chang, AM and Hallen, HD and Hess, HF and Kao, HL and Kwo, J and Sudbo, A and Chang, TY},
Title = {Scanning Hall-Probe Microscopy of a Vortex and Field
Fluctuations in La1.85Sr0.15CuO4 Films},
Journal = {Epl (Europhysics Letters)},
Volume = {20},
Number = {645},
Pages = {645-650},
Publisher = {European Physical Society},
Year = {1992},
ISSN = {1286-4854},
url = {http://dx.doi.org/10.1209/0295-5075/20/7/012},
Abstract = {A high-resolution scanning Hall-probe microscope is used to
spatially resolve vortices in high-temperature
superconducting La1.85Sr0.15CuO4 films. At low magnetic
fields, a disordered vortex arrangement is observed. A fit
to the surface field of an individual vortex is consistent
with one flux quantum, and is used to determine the local
penetration depth and its temperature dependence. At higher
fields, magnetic fluctuations are observed and compared to a
collective pinning model. For films grown with the c-axis
tilted from the surface normal, oval vortices are observed.
© 1992 IOP Publishing Ltd.},
Doi = {10.1209/0295-5075/20/7/012},
Key = {fds245756}
}
@article{rong:3646,
Author = {Rong, ZY and Chang, A and Wolf, EL},
Title = {A flexible implementation of scanning tunneling spectroscopy
utilizing C-language on the personal computer},
Journal = {Rev. Sci. Instr.},
Volume = {63},
Number = {7},
Pages = {3646-3651},
Publisher = {AIP},
Year = {1992},
url = {http://link.aip.org/link/?RSI/63/3646/1},
Keywords = {ELECTRON MICROSCOPY; PERSONAL COMPUTERS; COMPUTER
CALCULATIONS; ALGORITHMS; DATA ACQUISITION SYSTEMS;
COMPUTERIZED CONTROL SYSTEMS; DESIGN; ELECTRONIC CIRCUITS;
SCANNING TUNNELING MICROSCOPY; IV CHARACTERISTIC},
Key = {rong:3646}
}
@article{chang:5692,
Author = {Chang, A and Rong, ZY and Ivanchenko, YM and Lu, F and Wolf,
EL},
Title = {Observation of large tunneling-conductance variations in
direct mapping of the energy gap of single-crystal Bi[sub
2]Sr[sub 2]CaCu[sub 2]O[sub 8 - x]},
Journal = {Phys. Rev. B (Condensed Matter)},
Volume = {46},
Number = {9},
Pages = {5692-5698},
Publisher = {APS},
Year = {1992},
url = {http://link.aps.org/abstract/PRB/v46/p5692},
Keywords = {COPPER OXIDES; CALCIUM OXIDES; STRONTIUM OXIDES; BISMUTH
OXIDES; HIGH TC SUPERCONDUCTORS; MONOCRYSTALS; ENERGY
GAP; TUNNEL EFFECT; ELECTRIC CONDUCTIVITY; PROXIMITY EFFECT;
MULTI ELEMENT COMPOUNDS},
Key = {chang:5692}
}
@article{tao:10622,
Author = {Tao, HJ and Chang, A and Lu, F and Wolf, EL},
Title = {Electron tunneling spectroscopy of single-crystal Bi[sub
2]Sr[sub 2]CaCu[sub 2]O[sub 8]},
Journal = {Phys. Rev. B (Condensed Matter)},
Volume = {45},
Number = {18},
Pages = {10622-10632},
Publisher = {APS},
Year = {1992},
url = {http://link.aps.org/abstract/PRB/v45/p10622},
Keywords = {HIGH TC SUPERCONDUCTORS; BISMUTH OXIDES; STRONTIUM
OXIDES; CALCIUM OXIDES; COPPER OXIDES; MONOCRYSTALS; ENERGY
GAP; TEMPERATURE EFFECTS; BCS THEORY; TRANSITION
TEMPERATURE; MULTI ELEMENT COMPOUNDS},
Key = {tao:10622}
}
@article{chang:1974,
Author = {Chang, AM and Hallen, HD and Harriott, L and Hess, HF and Kao, HL and Kwo,
J and Miller, RE and Wolfe, R and Van Der Ziel and J and Chang,
TY},
Title = {Scanning Hall probe microscopy},
Journal = {Applied Physics Letters},
Volume = {61},
Number = {16},
Pages = {1974-1976},
Publisher = {AIP Publishing},
Year = {1992},
Month = {January},
ISSN = {0003-6951},
url = {http://link.aip.org/link/?APL/61/1974/1},
Keywords = {MAGNETOMETERS; MICROSCOPY; HALL EFFECT; MAGNETIC PROBES;
SURFACE MAGNETISM; SPATIAL RESOLUTION; SCANNING TUNNELING
MICROSCOPY; SENSITIVITY; POSITIONING; DOMAIN STRUCTURE;
MAGNETIC FLUX; FLUXLINE LATTICES},
Abstract = {We describe the implementation of a scanning Hall probe
microscope of outstanding magnetic field sensitivity (∼0.1
G) and unprecedented spatial resolution (∼0.35 μm) to
detect surface magnetic fields at close proximity to a
sample. Our microscope combines the advantages of a
submicron Hall probe fabricated on a GaAs/Al0.3Ga0.7As
heterostructure chip and the scanning tunneling microscopy
technique for precise positioning. We demonstrate its
usefulness by imaging individual vortices in high Tc
La1.85Sr0.15CuO4 films and superconducting networks, and
magnetic bubble domains.},
Doi = {10.1063/1.108334},
Key = {chang:1974}
}
@article{kurdak:6846,
Author = {Kurdak, C and Chang, AM and Chin, A and Chang, TY},
Title = {Quantum interference effects and spin-orbit interaction in
quasi-one-dimensional wires and rings},
Journal = {Physical Review. B, Condensed Matter},
Volume = {46},
Number = {11},
Pages = {6846-6856},
Publisher = {American Physical Society (APS)},
Year = {1992},
Month = {January},
ISSN = {0163-1829},
url = {http://link.aps.org/abstract/PRB/v46/p6846},
Keywords = {QUANTUM WIRES; GALLIUM ARSENIDES; ALUMINIUM ARSENIDES;
BINARY COMPOUNDS; TERNARY COMPOUNDS; HETEROJUNCTIONS;
AHARONOV BOHM EFFECT; TEMPERATURE RANGE 0000
0013 K; INTERFERENCE; COHERENCE LENGTH},
Abstract = {We study two kinds of quantum interference effects in
transportthe Aharonov-Bohm effect and the weak-localization
effectin quasi-one-dimensional wires and rings to address
issues concerning the phase-coherence length, spin-orbit
scattering, and the flux cancellation mechanism which is
predicted to be present when the elastic mean free path
exceeds the sample width. Our devices are fabricated on
GaAs/AlxGa1-xAs and pseudomorphic GaxIn1-xAs/AlxIn1- xAs
heterostructure materials and the experiments carried out at
0.420 K temperatures. In the GaAs/AlxGa1-xAs devices which
exhibit no significant spin-orbit scattering, we were able
to extract a phase-coherence length l from the amplitude of
the Aharonov-Bohm magnetoresistance oscillations in
different sized rings. We find it to be in agreement with l
deduced from the weak-localization data in parallel wires
when the one-dimensional weak-localization theory including
the flux cancellation mechanism is used to fit the data. We
therefore unambiguously establish that the same l governs
the behavior of the two quantum interference phenomena of
Aharonov-Bohm oscillations and weak localization, and that
the flux cancellation is in force. In the pseudomorphic
GaxIn1-xAs/AlxIn1-xAs heterostructure devices which exhibit
strong spin-orbit interaction effects, l exceeds the
spin-orbit-scattering length at low temperatures. The
amplitude of Aharonov-Bohm oscillations can only be
explained by introducing reduction factors due to spin-orbit
scattering. © 1992 The American Physical
Society.},
Doi = {10.1103/PhysRevB.46.6846},
Key = {kurdak:6846}
}
@article{chang:2114,
Author = {Chang, AM and Cunningham, JE},
Title = {Transport evidence for phase separation into spatial regions
of different fractional quantum Hall fluids near the
boundary of a two-dimensional electron gas},
Journal = {Physical Review Letters},
Volume = {69},
Number = {14},
Pages = {2114-2117},
Publisher = {American Physical Society (APS)},
Year = {1992},
Month = {January},
ISSN = {0031-9007},
url = {http://link.aps.org/abstract/PRL/v69/p2114},
Keywords = {HETEROJUNCTIONS; ELECTRON GAS; TRANSPORT PROCESSES; QUANTUM
HALL EFFECT; BOUNDARY CONDITIONS; PHASE SEPARATION; IV
CHARACTERISTIC},
Abstract = {Near the boundary, a 2D electron gas can phase separate into
fractional quantum Hall fluid regions of successively lower
filling factors (ν), in the case of a slowly increasing
boundary potential. We present experimental evidence in the
ν=1/3, 2/3, and 1 quantum Hall regimes on a four-lead Hall
junction showing that by side gating the junction boundary,
the Hall resistance can be made to approach the quantized
value of the lower ν fluids in the top-gated leads, rather
than the higher-ν fluid at the junction center. This
implies the presence of the lower-ν fluids near the
junction boundary. © 1992 The American Physical
Society.},
Doi = {10.1103/PhysRevLett.69.2114},
Key = {chang:2114}
}
@article{hallen:3007,
Author = {Hallen, HD and Seshadri, R and Chang, AM and Miller, RE and Pfeiffer,
LN and West, KW and Murray, CA and Hess, HF},
Title = {Direct spatial imaging of vortices in a superconducting wire
network},
Journal = {Physical Review Letters},
Volume = {71},
Number = {18},
Pages = {3007-3010},
Publisher = {American Physical Society (APS)},
Year = {1993},
Month = {January},
url = {http://link.aps.org/abstract/PRL/v71/p3007},
Keywords = {SUPERCONDUCTING WIRES; NETWORK STRUCTURE; GRIDS; TWO
DIMENSIONAL SYSTEMS; VORTICES; SPATIAL DISTRIBUTION; IMAGES;
MICROSCOPY; HALL EFFECT; GROUND STATES; DOMAIN STRUCTURE;
HOPPING; TEMPERATURE DEPENDENCE; GRAIN BOUNDARIES;
SUPERCONDUCTING COMPOSITES; NIOBIUM},
Abstract = {We report direct observations of vortices in a square
superconducting wire grid imaged using scanning Hall probe
microscopy. Real space images of vortex configurations are
obtained as a function of the flux per unit cell f by
measuring the local magnetic field just above the sample. At
f=1/2 we observe domains of the checkerboard ground state.
As f is reduced from 1/2 to 1/3 vacancies first penerate the
grain boundaries and then the checkerboard domains. Near
f=1/3 we observe domains of the 1/3 staircase ground state.
Heating the sample close to Tc produces correlated vortex
hopping. © 1993 The American Physical Society.},
Doi = {10.1103/PhysRevLett.71.3007},
Key = {hallen:3007}
}
@article{fds328561,
Author = {Hallen, HD and Hess, HF and Chang, AM and Pfeiffer, LN and West, KW and Mitzi, DB},
Title = {High-resolution scanning hall probe microscopy},
Journal = {Smart Structures and Materials 2005: Active Materials:
Behavior and Mechanics},
Volume = {1855},
Pages = {152-157},
Publisher = {SPIE},
Year = {1993},
Month = {June},
ISBN = {0-8194-1081-0},
url = {http://dx.doi.org/10.1117/12.146371},
Abstract = {A high resolution scanning Hall probe microscope is used to
spatially resolve vortices in high temperature
superconducting Bi2Sr2CaCu2O8+δ crystals. We observe a
partially ordered vortex lattice at several different
applied magnetic fields and temperatures. At higher
temperatures, a limited amount of vortex re-arrangement is
observed, but most vortices remain fixed for periods long
compared to the imaging time of several hours even at
temperatures as high as 75°K (the superconducting
transition temperature for these crystals is ∼84°K). A
measure of the local magnetic penetration depth can be
obtained from a fit to the surface field of several
neighboring vortices, and has been measured as a function of
temperature. In particular, we have measured the zero
temperature penetration depth and found it to be 275 ± 40
nm.},
Doi = {10.1117/12.146371},
Key = {fds328561}
}
@article{chang:2111,
Author = {Chang, AM and Baranger, HU and Pfeiffer, LN and West,
KW},
Title = {Weak localization in chaotic versus nonchaotic cavities: A
striking difference in the line shape.},
Journal = {Physical Review Letters},
Volume = {73},
Number = {15},
Pages = {2111-2114},
Publisher = {APS},
Year = {1994},
Month = {October},
url = {http://www.ncbi.nlm.nih.gov/pubmed/10056974},
Keywords = {TRANSPORT PROCESSES; CHAOTIC SYSTEMS; SCATTERING; CAVITY
RESONATORS; MAGNETORESISTANCE; AHARONOV BOHM EFFECT;
QUANTUM WELLS; COHERENCE LENGTH},
Doi = {10.1103/physrevlett.73.2111},
Key = {chang:2111}
}
@article{fds245775,
Author = {Alers, GB and Monroe, D and Krisch, KS and Weir, BE and Chang,
AM},
Title = {1/f noise in the tunneling current of thin gate
oxides},
Journal = {Materials Research Society Symposium Proceedings},
Volume = {428},
Pages = {311-315},
Year = {1996},
Month = {January},
url = {http://dx.doi.org/10.1557/proc-428-311},
Abstract = {We have observed fluctuations in the tunneling current
through 3.5 nm gate oxides with a 1/f power spectrum where f
is the frequency. For voltages in the direct tunneling
regime we find an anomalous current dependence of the noise
relative to previous observations of noise in thin oxides.
We present a simplified model for the current noise in terms
of fluctuations in a trap assisted tunneling current that
exists in the oxide in addition to the direct tunneling
current. Current noise appears to be a very sensitive probe
of trap assisted tunneling and degradation in
oxides.},
Doi = {10.1557/proc-428-311},
Key = {fds245775}
}
@article{fds245776,
Author = {Hallen, HD and Chang, AM and Miller, R and Pfeiffer, LN and West, K and Hess, HF},
Title = {Penetration of laterally quantized flux lamina into a
superconducting wire network},
Journal = {Solid State Communications},
Volume = {99},
Number = {9},
Pages = {651-654},
Publisher = {Elsevier BV},
Year = {1996},
Month = {January},
url = {http://dx.doi.org/10.1016/0038-1098(96)00123-8},
Abstract = {We report direct, high resolution images of the magnetic
field above a superconducting wire grid as applied flux
penetrates into an initially empty state or into a state
with half the plaquettes containing a magnetic quantum. We
find two qualitatively different initial approaches to
equilibrium: in wide structures for the former, or with
long, linear structures for the latter case. In the approach
to an empty state, we observe the formation of residual
quasi-bound magnetic vortex/anti-vortex pairs. Copyright ©
1996 Elsevier Science Ltd.},
Doi = {10.1016/0038-1098(96)00123-8},
Key = {fds245776}
}
@article{chang:2538,
Author = {Chang, AM and Pfeiffer, LN and West, KW},
Title = {Observation of Chiral Luttinger Behavior in Electron
Tunneling into Fractional Quantum Hall Edges},
Journal = {Physical Review Letters},
Volume = {77},
Number = {12},
Pages = {2538-2541},
Publisher = {American Physical Society (APS)},
Year = {1996},
Month = {January},
url = {http://link.aps.org/abstract/PRL/v77/p2538},
Keywords = {QUANTUM HALL EFFECT; TUNNEL EFFECT; CHIRALITY; ELECTRON GAS;
MAGNETIC FIELDS; IV CHARACTERISTIC; GALLIUM
ARSENIDES},
Abstract = {We measure the tunneling conductance (G) and current-voltage
(I–V) characteristics for electron tunneling from a bulk
doped-GaAs normal metal into the abrupt edge of a fractional
quantum Hall effect. We observe clear power law behavior for
both the I–V relationship and the conductance versus
temperature. For tunneling into the ν=1/3 edge the power
law persists for one decade in V (T), and 2.7 (1.7) decades
in I(G). This strongly indicates the 1/3 edge behaves like a
chiral Luttinger liquid. In contrast, the ν=1 edge is
essentially linear, while the 2/3 edge is slightly
nonlinear. © 1996 The American Physical
Society.},
Doi = {10.1103/PhysRevLett.77.2538},
Key = {chang:2538}
}
@article{chang:1695,
Author = {Chang, AM and Baranger, HU and Pfeiffer, LN and West, KW and Chang,
TY},
Title = {Non-Gaussian distribution of Coulomb blockade peak heights
in quantum dots.},
Journal = {Physical Review Letters},
Volume = {76},
Number = {10},
Pages = {1695-1698},
Publisher = {APS},
Year = {1996},
Month = {March},
url = {http://www.ncbi.nlm.nih.gov/pubmed/10060494},
Keywords = {QUANTUM DOTS; TUNNELING; IV CHARACTERISTIC; COULOMB FIELD;
GALLIUM ARSENIDES; ALUMINIUM ARSENIDES},
Doi = {10.1103/physrevlett.76.1695},
Key = {chang:1695}
}
@article{alers:2885,
Author = {Alers, GB and Krisch, KS and Monroe, D and Weir, BE and Chang,
AM},
Title = {Tunneling current noise in thin gate oxides},
Journal = {Applied Physics Letters},
Volume = {69},
Number = {19},
Pages = {2885-2887},
Publisher = {AIP Publishing},
Year = {1996},
Month = {November},
url = {http://link.aip.org/link/?APL/69/2885/1},
Keywords = {INTEGRATED CIRCUITS; SI JUNCTIONS; TUNNEL EFFECT; GATES; IV
CHARACTERISTIC; NOISE; TRANSIENTS; SILICON},
Abstract = {We have examined fluctuations in the tunneling current of
3.5 nm SiO2 barriers for voltages in the direct tunneling
regime. We find a 1/f power law for the spectral density of
the fluctuations where f is the frequency. This 1/f noise
can be attributed to fluctuations of a trap assisted
tunneling current through the oxide that causes current
noise but is not evident in the I-V curves. We suggest that
this noise may be a more sensitive probe of trap assisted
tunneling and degradation in thin oxides than other
measures. At voltages above a threshold of 2.5 V, we observe
the reversible onset of non-Gaussian current transients in
the noise. The onset of these current transients can be
related to a transition in the spacial uniformity of the
tunneling current density that may result in eventual
breakdown of the oxide. © 1996 American Institute of
Physics.},
Doi = {10.1063/1.117351},
Key = {alers:2885}
}
@article{fds245777,
Author = {Chang, AM},
Title = {Quantum chaos in Ga/AlxGa1-xAs
microstructures},
Journal = {Chaos, Solitons and Fractals},
Volume = {8},
Number = {7-8},
Pages = {1281-1297},
Year = {1997},
Abstract = {We report distinct signatures of 'quantum chaos' in both
open and closed systems. Quantum chaos refers to the quantum
signature of systems which classically exhibit chaotic
dynamics. In the open case, we measure the line shape of the
negative magneto-resistance peak in ballistic cavities
fabricated on very high quality GaAs/AlxGa1-xAs
heterostructures. We find a striking difference in the line
shape for chaotic, stadium cavities versus non-chaotic,
circle cavities: Lorentzian versus triangular. In the case
of closed systems, we study the distribution of Coulomb
blockade conductance peak heights in individual quantum
dots. We find a strongly non-Gaussian distribution and a
significant difference between the zero and non-zero
magnetic fields. While the zero magnetic field distribution
is related to the well-known Porter-Thomas distribution of
resonance widths in the scattering of neutrons from nuclei,
the non-zero magnetic field distribution is completely new
and previously unobserved. © 1997 Elsevier Science
Ltd.},
Key = {fds245777}
}
@article{fds322932,
Author = {Chang, AM},
Title = {Quantum chaos in Ga/AlxGa1-xAs
microstructures},
Journal = {Chaos, Solitons & Fractals},
Volume = {8},
Number = {7-8},
Pages = {1281-1297},
Publisher = {Elsevier BV},
Year = {1997},
Month = {January},
url = {http://dx.doi.org/10.1016/S0960-0779(97)00020-9},
Abstract = {We report distinct signatures of 'quantum chaos' in both
open and closed systems. Quantum chaos refers to the quantum
signature of systems which classically exhibit chaotic
dynamics. In the open case, we measure the line shape of the
negative magneto-resistance peak in ballistic cavities
fabricated on very high quality GaAs/AlxGa1-xAs
heterostructures. We find a striking difference in the line
shape for chaotic, stadium cavities versus non-chaotic,
circle cavities: Lorentzian versus triangular. In the case
of closed systems, we study the distribution of Coulomb
blockade conductance peak heights in individual quantum
dots. We find a strongly non-Gaussian distribution and a
significant difference between the zero and non-zero
magnetic fields. While the zero magnetic field distribution
is related to the well-known Porter-Thomas distribution of
resonance widths in the scattering of neutrons from nuclei,
the non-zero magnetic field distribution is completely new
and previously unobserved. © 1997 Elsevier Science
Ltd.},
Doi = {10.1016/S0960-0779(97)00020-9},
Key = {fds322932}
}
@article{grayson:1062,
Author = {Grayson, M and Tsui, DC and Pfeiffer, LN and West, KW and Chang,
AM},
Title = {Continuum of chiral luttinger liquids at the fractional
quantum hall edge},
Journal = {Physical Review Letters},
Volume = {80},
Number = {5},
Pages = {1062-1065},
Publisher = {American Physical Society (APS)},
Year = {1998},
Month = {January},
url = {http://link.aps.org/abstract/PRL/v80/p1062},
Keywords = {Luttinger liquid; quantum Hall effect; chirality;
tunnelling; gallium arsenide; electrical
conductivity},
Abstract = {We study current versus voltage (I-V) when tunneling into
the edge of the fractional quantum Hall effect over a
continuum of filling factors (ν) from 1/4 to 1. Our devices
manifest the power law I-V behavior previously observed by
Chang et al. at discrete fillings, but now with as many as
six decades in current and over the whole range of filling
factor suggesting the existence of a continuum of chiral
Luttinger liquids. Surprisingly the exponent behaves
approximately as 1/ν and does not exhibit the strong
plateau features predicted in recent theoretical works based
on the intermixing of copropagating and counterpropagating
multiple edge modes. © 1998 American Physical
Society.},
Doi = {10.1103/PhysRevLett.80.1062},
Key = {grayson:1062}
}
@article{gammel:833,
Author = {Gammel, PL and Yaron, U and Ramirez, AP and Bishop, DJ and Chang, AM and Ruel, R and Pfeiffer, LN and Bucher, E and D’anna, G and Huse, A and Mortensen, K and Eskildsen, MR and Kes, PH},
Title = {Structure and correlations of the flux line lattice in
crystalline nb through the peak effect},
Journal = {Physical Review Letters},
Volume = {80},
Number = {4},
Pages = {833-836},
Publisher = {American Physical Society (APS)},
Year = {1998},
Month = {January},
url = {http://link.aps.org/abstract/PRL/v80/p833},
Keywords = {niobium; flux-line lattice; flux pinning; critical current
density (superconductivity); neutron diffraction;
correlation theory},
Abstract = {We have measured the structure of the field cooled flux line
lattice (FLL) in single crystal Nb using small angle neutron
scattering. Augmented by transport and thermodynamic data, a
scenario for the dramatic disordering of the FLL near the
peak effect emerges. A precursor to the peak effect is an
hexatic FLL as positional order is lost. As the critical
current rises, the orientational and longitudinal
correlation lengths also fall, leading to an amorphous array
of lines at the critical current maximum. © 1998 American
Physical Society.},
Doi = {10.1103/PhysRevLett.80.833},
Key = {gammel:833}
}
@article{fds245778,
Author = {Chang, AM and Pfeiffer, LN and West, KW},
Title = {An apparent g = 1/2 chiral Luttinger liquid at the edge of
the v = 1/2 compressible composite Fermion
liquid},
Journal = {Physica B: Condensed Matter},
Volume = {249-251},
Pages = {383-387},
Publisher = {Elsevier BV},
Year = {1998},
Month = {June},
url = {http://dx.doi.org/10.1016/S0921-4526(98)00136-7},
Abstract = {The conductance (G) and current-voltage (I - V)
characteristics are investigated for electron tunneling into
the edge of the v = 1/2 gapless quantum Hall composite
Fermion liquid. A non-linear, power law I-V and a power-law
temperature dependence in G are observed. We deduce an I-V
exponent of 1.91 (∼2) and a corresponding tunneling
conductance temperature exponent of 0.77 (∼1). These
values are surprisingly close to those expected for a
one-dimensional chiral Luttinger liquid with an intrinsic
dimensionless conductance of g = 1/2. © 1998 Elsevier
Science B. V. All rights reserved.},
Doi = {10.1016/S0921-4526(98)00136-7},
Key = {fds245778}
}
@article{fds245749,
Author = {Chang, AM},
Title = {Chiral Luttinger Liquids at the Fractional Quantum Hall
Edge},
Journal = {Proceedings of the Centennial OCPA conference},
Year = {1999},
Key = {fds245749}
}
@article{sperl:3165,
Author = {Sperl, M and Chang, A and Weber, N and Hubler, A},
Title = {Hebbian learning in the agglomeration of conducting
particles},
Journal = {Phys. Rev. E (Statistical Physics, Plasmas, Fluids, and
Related Interdisciplinary Topics)},
Volume = {59},
Number = {3},
Pages = {3165-3168},
Publisher = {APS},
Year = {1999},
url = {http://link.aps.org/abstract/PRE/v59/p3165},
Keywords = {neural nets; Hebbian learning; surface mount
technology},
Key = {sperl:3165}
}
@article{fds245779,
Author = {Chang, AM},
Title = {Quantum chaos in GaAs/AlxGa1-xAs
microstructures},
Journal = {Physica Scripta T},
Volume = {90},
Pages = {16-25},
Year = {2001},
Abstract = {We review clear signatures of "quantum chaos" observable in
both open and closed systems realized in GaAs/AlxGa1-xAs
microstructures. In open ballistic billiards where
scattering dynamics determine the characteristics of quantum
transport, we find a striking difference in the shape of the
negative magneto-resistance peak for transport through
chaotic, stadium cavities-Lorentzian line shape, versus
non-chaotic, circle cavities-unusual triangular line shape.
In a nearly closed system of individual quantum dot
single-electron-transistors, the distribution of the height
of Coulomb blockade conductance peaks is strongly
non-Gaussian and sensitive to the absence or presence of a
magnetic field. Even though our findings are in substantial
agreement with the prediction of Random Matrix Theory, there
exist evidence that deviations can occur due to the effect
of electron-electron interaction. Lastly, we briefly
summarize recent observations of pairing effect in
ultra-small quantum dots associated with the spin degree of
freedom.},
Key = {fds245779}
}
@article{chang:143,
Author = {Chang, AM and Wu, MK and Chi, CC and Pfeiffer, LN and West,
KW},
Title = {Plateau behavior in the chiral Luttinger liquid
exponent},
Journal = {Physical Review Letters},
Volume = {86},
Number = {1},
Pages = {143-146},
Publisher = {American Physical Society (APS)},
Year = {2001},
Month = {January},
url = {http://link.aps.org/abstract/PRL/v86/p143},
Keywords = {quantum Hall effect; Luttinger liquid; tunnelling; ground
states},
Abstract = {Results indicating the presence of a plateau feature for the
α versus 1/v dependence with an α value close to 3 are
discussed. These results have been obtained in two sets of
samples studied via analysis of I-V tunneling data and
statistical F-test.},
Doi = {10.1103/PhysRevLett.86.143},
Key = {chang:143}
}
@article{grayson:2645,
Author = {Tsui, DC and Pfeiffer, LN and West, KW and Grayson, M and Chang,
AM},
Title = {Resonant tunneling into a biased fractional quantum Hall
edge},
Journal = {Physical Review Letters},
Volume = {86},
Number = {12},
Pages = {2645-2648},
Publisher = {American Physical Society (APS)},
Year = {2001},
Month = {March},
url = {http://link.aps.org/abstract/PRL/v86/p2645},
Keywords = {quantum Hall effect; resonant tunnelling; Luttinger liquid;
spectral line breadth; electronic density of states; gallium
arsenide},
Abstract = {The voltage dependence of a new type of resonance at a sharp
fractional quantum Hall effect (FQHE) edge was
characterized. Clear non-Fermi liquid (non-FL) behavior
through line shape analysis and nonconservation of resonance
area was demonstrated.},
Doi = {10.1103/PhysRevLett.86.2645},
Key = {grayson:2645}
}
@article{fds245780,
Author = {Chang, AM},
Title = {Resistance of a perfect wire},
Journal = {Nature},
Volume = {411},
Number = {6833},
Pages = {39-40},
Publisher = {Springer Nature},
Year = {2001},
Month = {May},
url = {http://dx.doi.org/10.1038/35075201},
Abstract = {Intuition tells us that a wire without defects should have
zero resistance. But in the real world all conductors,
however perfect, have some resistance. A new study confirms
that electrical contacts are the problem.},
Doi = {10.1038/35075201},
Key = {fds245780}
}
@article{fds245781,
Author = {Jeong, H and Chang, AM and Melloch, MR},
Title = {The Kondo effect in an artificial quantum dot
molecule.},
Journal = {Science (New York, N.Y.)},
Volume = {293},
Number = {5538},
Pages = {2221-2223},
Year = {2001},
Month = {September},
url = {http://dx.doi.org/10.1126/science.1063182},
Abstract = {Double quantum dots provide an ideal model system for
studying interactions between localized impurity spins. We
report on the transport properties of a series-coupled
double quantum dot as electrons are added one by one onto
the dots. When the many-body molecular states are formed, we
observe a splitting of the Kondo resonance peak in the
differential conductance. This splitting reflects the energy
difference between the bonding and antibonding states formed
by the coherent superposition of the Kondo states of each
dot. The occurrence of the Kondo resonance and its magnetic
field dependence agree with a simple interpretation of the
spin status of a double quantum dot.},
Doi = {10.1126/science.1063182},
Key = {fds245781}
}
@article{fds245782,
Author = {Grayson, M and Tsui, DC and Pfeiffer, LN and West, KW and Chang,
AM},
Title = {The lever-arm model: Describing resonant tunneling under
bias at a fractional quantum Hall edge},
Journal = {Physica E: Low Dimensional Systems and Nanostructures},
Volume = {12},
Number = {1-4},
Pages = {80-83},
Publisher = {Elsevier BV},
Year = {2002},
Month = {January},
ISSN = {1386-9477},
url = {http://dx.doi.org/10.1016/S1386-9477(01)00247-8},
Abstract = {New tunnel current measurements of resonant tunneling at
voltage-biased quantum Hall effect edge were reported.
Results showed that the tunneling density of states at a
sharp quantum Hall edge obeyed a power-law form. The fits to
this data demonstrated the robustness of the lever-arm model
in quantitatively describing all observed features
associated with the tunneling resonance.},
Doi = {10.1016/S1386-9477(01)00247-8},
Key = {fds245782}
}
@article{fds245783,
Author = {Chang, AM},
Title = {Is the chiral Luttinger liquid exponent universal?},
Journal = {Comptes Rendus Physique},
Volume = {3},
Number = {6},
Pages = {677-684},
Publisher = {Elsevier BV},
Year = {2002},
Month = {July},
url = {http://dx.doi.org/10.1016/S1631-0705(02)01353-1},
Abstract = {We present experimental evidence from electron tunneling
measurements that the chiral Luttinger liquid power-law
exponent, α, for tunneling into the fractional quantum Hall
edge deviates substantially from the universal behavior
predicted by theory. Our results suggest that the existing
standard analyses based on effective Chern-Simon field
theories deserve careful reexamination when applied to the
dynamics at the Hall fluid edge. © 2002 Académie des
sciences/Éditions scientifiques et médicales Elsevier
SAS.},
Doi = {10.1016/S1631-0705(02)01353-1},
Key = {fds245783}
}
@article{fds245752,
Author = {Chang, AM},
Title = {Novel Phenomena in Small Individual and Coupled Quantum
Dots},
Series = {Kluwer Academic/Plenum Publishers},
Pages = {123 pages},
Booktitle = {ELECTRON TRANSPORT IN QUANTUM DOTS},
Publisher = {Kluwer Academic Publishers},
Editor = {Bird, JP},
Year = {2003},
Abstract = {<p>We discuss several novel phenomena observed in individual
or coupled quan-tum dots fabricated in GaAs/Al_xGa_{1-x}As
materials, where the lithographic dot- size ranges from
350nm down to 120nm. These include distinct signatures of
"quantum chaos" as evidenced in the highly non-Gaussian
distributionof Coulomb blockade conductance peak heights in
individual quantum dots, which are related to the well-known
Porter-Thomas distribution of resonance widths in the
scattering of neutrons from nuclei, spin physics in
individualdots manifested in the even-odd (pairing) effect
and in the Kondo effect, and spin physics in an artificial,
double-quantum-dot molecule as evidenced by theclear
observation of the coherent Kondo effect. These significant
observations may have ramifications for future
implementation of the coupled-quantum-dotsystem for quantum
computation.},
Key = {fds245752}
}
@article{fds245844,
Author = {Chang, AM},
Title = {Chiral Luttinger Liquids at the Fractional Quantum Hall
Edge},
Journal = {Review of Modern Physics},
Volume = {75},
Number = {4},
Pages = {1449-1505},
Publisher = {American Physical Society (APS)},
Year = {2003},
Month = {October},
ISSN = {0034-6861},
url = {http://dx.doi.org/10.1103/RevModPhys.75.1449},
Abstract = {http://ojps.aip.org/dbt/dbt.jsp?KEY=RMPHAT&Volume=75&Issue=4},
Doi = {10.1103/RevModPhys.75.1449},
Key = {fds245844}
}
@article{fds245843,
Author = {Chang, AM},
Title = {Transition between Quantum States in a Parallel-Coupled
Double Quantum Dot},
Journal = {Physical Review Letters},
Volume = {92},
Number = {17},
Pages = {176801},
Publisher = {American Physical Society (APS)},
Year = {2004},
Month = {April},
url = {http://dx.doi.org/10.1103/PhysRevLett.92.176801},
Abstract = {Strong electron and spin correlations in a double quantum
dot (DQD) can give rise to different quantum states.We
observe a continuous transition from a Kondo state
exhibiting a single-peak Kondo resonance to another
exhibiting a double peak by increasing the interdot coupling
(t) in a parallel-coupled DQD. The transition into the
double-peak state provides evidence for spin entanglement
between the excess electrons on each dot. Toward the
transition, the peak splitting merges and becomes
substantially smaller than t because of strong Coulomb
effects. Our device tunability bodes well for future quantum
computation applications.},
Doi = {10.1103/PhysRevLett.92.176801},
Key = {fds245843}
}
@article{fds245803,
Author = {Altomare, F and Chang, AM and Melloch, MR and Hong, Y and Tu,
CW},
Title = {Ultranarrow AuPd and Al Wires},
Journal = {Applied Physics Letters},
Volume = {86},
Number = {17},
Pages = {172501},
Publisher = {AIP Publishing},
Year = {2005},
ISSN = {0003-6951},
url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000229185500036&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
Abstract = {In this letter, we discuss a versatile template technique
aimed to the fabrication of sub-10 nm wide wires. Using this
technique, we have measured AuPd wires, 12 nm wide and as
long as 20 µm. Even materials that form a strong
superficial oxide, and thus not suited to be used in
combination with other techniques, can be employed. In
particular, we have measured Al wires, with lateral width
smaller or comparable to 10 nm, and length exceeding 10
µm.},
Doi = {10.1063/1.1905806},
Key = {fds245803}
}
@article{fds245784,
Author = {Chang, AM},
Title = {The Kondo effect and controlled spin entanglement in coupled
double-quantum-dots},
Journal = {Aip Conference Proceedings},
Volume = {777},
Pages = {100-111},
Publisher = {AIP},
Year = {2005},
Month = {July},
ISBN = {0735402639},
ISSN = {0094-243X},
url = {http://dx.doi.org/10.1063/1.1996875},
Abstract = {Semiconductor double-quantum dots represent an ideal system
for studying the novel spin physics of localized spins. On
each quantum dot when the number of electrons is odd and the
net spin is 1/2, a strong coupling of this localized spin to
conducting electrons in the leads gives rise to Kondo
correlation. On the other hand, in the coupled
double-quantum-dot if the inter-dot antiferromagnetic
interaction is strong, the two spins can form a correlated
spin-singlet state, quenching the Kondo effect. This
competition between Kondo and antiferromagnetic correlation
is studied in a controlled manner by tuning the inter-dot
tunnel coupling. Increasing the inter-dot tunneling, we
observe a continuous transition from a single-peaked to a
double-peaked Kondo resonance in the differential
conductance. On the double-peaked side, the differential
conductance becomes suppressed at zero source-drain bias.
The observed strong suppression of the differential
conductance at zero bias provides direct evidence signaling
the formation of an entangled spin-singlet state. This
evidence for entanglement and the tunability of our devices
bode well for quantum computation applications. © 2005
American Institute of Physics.},
Doi = {10.1063/1.1996875},
Key = {fds245784}
}
@article{fds245802,
Author = {Butt, NZ and Chang, AM and Raza, H and Bashir, R and Liu, J and Kwong,
DL},
Title = {Low-Frequency Noise Statistics for the Breakdown
Characterization of Ultrathin Gate Oxides},
Journal = {Applied Physics Letters},
Volume = {88},
Number = {11},
Pages = {112901},
Publisher = {AIP Publishing},
Year = {2006},
ISSN = {0003-6951},
url = {http://dx.doi.org/10.1063/1.2186114},
Abstract = {We have investigated the statistics of low-frequency noise
in the tunneling current of ultrathin oxides (2.5-4 nm) in
metal-oxide-semiconductor capacitors as a function of the
applied voltage stress. The statistical analysis includes
(i) non-Gaussianity (nG), which is a measure of the degree
of temporal correlation in the noise, and (ii) ratio of
integrated noise power to the dc leakage current (R). The
occurrence of high peaks in nG indicates the appearance of
new percolation paths, and the subsequent conduction through
these paths is indicated by R. Our results show that the nG
and R characteristics are generic for the oxides of
different thickness and growth quality and have the
potential, in conjunction with leakage itself, of being used
as a prognosticator of oxide reliability. © 2006 American
Institute of Physics.},
Doi = {10.1063/1.2186114},
Key = {fds245802}
}
@article{fds245801,
Author = {Altomare, F and Chang, AM and Melloch, MR and Hong, Y and Tu,
CW},
Title = {Evidence for macroscopic quantum tunneling of phase slips in
long one-dimensional superconducting Al wires.},
Journal = {Physical Review Letters},
Volume = {97},
Number = {1},
Pages = {017001},
Year = {2006},
Month = {July},
ISSN = {0031-9007},
url = {http://dx.doi.org/10.1103/physrevlett.97.017001},
Abstract = {Quantum phase slips have received much attention due to
their relevance to superfluids in reduced dimensions and to
models of cosmic string production in the early universe.
Their establishment in one-dimensional superconductors has
remained controversial. Here we study the nonlinear
current-voltage characteristics and linear resistance in
long superconducting Al wires with lateral dimensions
approximately 5 nm. We find that, in a magnetic field and at
temperatures well below the superconducting transition, the
observed behaviors can be described by the nonclassical,
macroscopic quantum tunneling of phase slips, and are
inconsistent with the thermal activation of phase
slips.},
Doi = {10.1103/physrevlett.97.017001},
Key = {fds245801}
}
@article{fds140966,
Author = {A. Bove and F. Altomare and N. Kundtz and A.M. Chang and Y.J. Cho and X.
Liu and J. Furdyna},
Title = {Electron-mediated ferromagnetism and small spin-orbit
interaction in molecular-beam-epitaxy grown n-type
GaAs/Al0.3Ga0.7As heterostructures with Mn
δ-doping},
Year = {2007},
Abstract = {We report the first evidence of electron mediated
ferromagnetism in a molecular-beam-epitaxy (MBE) grown
GaAs/Al0.3Ga0.7As heterostructure with Mn δ-doping. The
interaction between the magnetic dopants (Mn) and the
2-dimensional electron gas (2DEG) realizes magnetic ordering
when the temperature is below the Curie temperature
(TC~3.2K) and the 2DEG is brought in close proximity to the
Mn layer by gating.},
Key = {fds140966}
}
@article{fds245786,
Author = {Altomare, F and Chang, AM and Melloch, MR and Hong, Y and Tu,
CW},
Title = {Erratum: Evidence for macroscopic quantum tunneling of phase
slips in long one-dimensional superconducting Al wires
(Physical Review Letters (2006) 97 (017001))},
Journal = {Physical Review Letters},
Volume = {98},
Number = {16},
Publisher = {American Physical Society (APS)},
Year = {2007},
Month = {April},
ISSN = {0031-9007},
url = {http://dx.doi.org/10.1103/PhysRevLett.98.169901},
Doi = {10.1103/PhysRevLett.98.169901},
Key = {fds245786}
}
@article{fds245785,
Author = {Altomare, F and Chang, AM and Melloch, MR and Hong, Y and Tu,
CW},
Title = {Erratum: Ultranarrow AuPd and Al wires (Applied Physics
Letters (2005) 86 (172501))},
Journal = {Applied Physics Letters},
Volume = {90},
Number = {17},
Pages = {179902-179902},
Publisher = {AIP Publishing},
Year = {2007},
Month = {May},
ISSN = {0003-6951},
url = {http://dx.doi.org/10.1063/1.2731309},
Doi = {10.1063/1.2731309},
Key = {fds245785}
}
@article{fds245800,
Author = {Fang, ZL and Wu, P and Kundtz, N and Chang, AM and Liu, XY and Furdyna,
JK},
Title = {Spin-dependent resonant tunneling through 6 μm diameter
double barrier resonant tunneling diode},
Journal = {Applied Physics Letters},
Volume = {91},
Number = {2},
Pages = {022101-022101},
Publisher = {AIP Publishing},
Year = {2007},
Month = {August},
ISSN = {0003-6951},
url = {http://dx.doi.org/10.1063/1.2751132},
Abstract = {A vertical resonant tunneling diode based on the
paramagnetic Zn1-x-y Mny Cdx Se system has been fabricated
with a pillar diameter down to ∼6 μm. The diode exhibits
high quality resonant tunneling characteristics through the
electron subband of the quantum well at a temperature of 4.2
K, where a clear phonon replica was observable in addition
to the primary peak. Both peaks show a giant Zeeman
splitting in an applied magnetic field. Employing a
self-consistent real-time Green's function method, the
current-voltage characteristic was simulated, showing good
agreement with the measured result. © 2007 American
Institute of Physics.},
Doi = {10.1063/1.2751132},
Key = {fds245800}
}
@article{fds152839,
Author = {A. Bove and F. Altomare and N. B. Kundtz and Albert M. Chang and Y. J.
Cho and X. Liu and J. Furdyna},
Title = {A novel technique to make Ohmic contact to a buried
two-dimensional electron gas in a molecular-beam-epitaxy
grown $GaAs/Al_{0.3}Ga_{0.7}As$ heterostructure with Mn
$\delta$-doping},
Year = {2008},
Abstract = {We report on the growth and characterization of a new
Diluted Magnetic Semiconductor (DMS) heterostructure that
presents a Two-Dimensional Electron Gas (2DEG) with a
carrier density $n \sim 1.08 \times 10^{12} cm^{-2}$ and a
mobility $\mu \sim 600 cm^{2} / (Vs)$ at T $\sim$ 4.2K. As
far as we know this is the highest mobility value reported
in the literature for GaMnAs systems. A novel technique was
developed to make Ohmic contact to the buried 2DEG without
destroying the magnetic properties of our
crystal.},
Key = {fds152839}
}
@article{fds167455,
Author = {Peng Li and Phillip M. Wu and A.M. Chang},
Title = {Can a 1-dimensional Superconducting Nanowire Behave Like a
Josephson Junction},
Year = {2009},
Abstract = {The switching current ($I_s$) from the superconducting to
normal state in Aluminum nanowires is studied. In the range
0.3 - 1.4 K, $I_s$ fluctuations first increase and then
decrease as the temperature rises. This behavior is
consistent with a scenario where the resistive transition is
triggered by a single phase slips at low temperature and by
multiple consecutive phase slips at higher temperatures. The
phase slip process is predominantly thermally-assisted
except below 0.4 K, where possible quantum tunneling
contributions appear. Our results suggest that ultra-narrow
superconducting nanowires can exhibit behaviors similar to
under-damped Josephson junctions.},
Key = {fds167455}
}
@article{fds245799,
Author = {Wu, MK and Hsu, FC and Yeh, KW and Huang, TW and Luo, JY and Wang, MJ and Chang, HH and Chen, TK and Rao, SM and Mok, BH and Chen, CL and Huang, YL and Ke, CT and Wu, PM and Chang, AM and Wu, CT and Perng,
TP},
Title = {The development of the superconducting PbO-type β-FeSe and
related compounds},
Journal = {Physica C: Superconductivity},
Volume = {469},
Number = {9-12},
Pages = {340-349},
Publisher = {Elsevier BV},
Year = {2009},
Month = {May},
ISSN = {0921-4534},
url = {http://dx.doi.org/10.1016/j.physc.2009.03.022},
Abstract = {An overview of the recent development of the superconducting
FeSe1-x and related compounds is presented. Methods to
synthesize high purity polycrystalline samples, single
crystals and thin films with preferred orientation are
described. In addition to the synthesis of FeSe and FeSeTe,
the effects of various partial chemical substitutions on Fe
and Se/Te site are described. It was found that the effects
of chemical doping to the Se-site or Fe-site are rather
different. Ionic size of the dopant is found to play a
critical role on the occurrence of superconductivity. We
also review the physical properties, including transport,
magnetic, and thermal properties. There exist interesting
transport anomalies in the resistivity at low temperature,
and it was found that a structural distortion at low
temperature is critical to the occurrence of
superconductivity in these materials. However, the exact
origin of these observed anomalies is not clear, and the
exact pairing symmetry in FeSe-based superconductors is also
still in question. © 2009.},
Doi = {10.1016/j.physc.2009.03.022},
Key = {fds245799}
}
@article{fds245798,
Author = {Mok, BH and Rao, SM and Ling, MC and Wang, KJ and Ke, CT and Wu, PM and Ye,
KW and Wu, TB and Chang, AM and Wu, MK},
Title = {Growth and Investigation of Crystals of the New
Superconductor alpha-FeSe from KC1 Solutions},
Journal = {CRYSTAL GROWTH & DESIGN},
Volume = {9},
Number = {7},
Pages = {3260-3264},
Publisher = {American Chemical Society (ACS)},
Year = {2009},
Month = {July},
ISSN = {1528-7483},
url = {http://dx.doi.org/10.1021/cg801423g},
Abstract = {Crystals of FeSe0.88 and FeSeMn0.1 have been grown from KCl
solutions. Crystals measuring 2-3 mm across and 0.1-0.3 mm
thick grow with a hexagonal plate like habit. Powder X-ray
diffraction (XRD) measurements show strong peaks
corresponding to the tetragonal alpha-FeSe phase and weak
hexagonal beta-FeSe peaks in both cases. The plate side of
the crystal is identified to he the (101) face of the
tetragonal alpha-FeSe. Energy dispersive X-ray spectroscopic
(EDS) measurements show that Mn substitutes for Fe. Both
types of crystals show a superconducting transition at 8 K
in the DC magnetization measurements and a broad resistive
transition with zero resistance at 7.5 K with an onset at 11
K. Specific heat measurements also confirm bulk
superconductivity in the crystals. Crystals could also be
grown using KBr as a solvent.},
Doi = {10.1021/cg801423g},
Key = {fds245798}
}
@article{fds245796,
Author = {Wang, MJ and Luo, JY and Huang, TW and Chang, HH and Chen, TK and Hsu, FC and Wu, CT and Wu, PM and Chang, AM and Wu, MK},
Title = {Crystal orientation and thickness dependence of the
superconducting transition temperature of tetragonal FeSe1-x
thin films.},
Journal = {Physical Review Letters},
Volume = {103},
Number = {11},
Pages = {117002},
Year = {2009},
Month = {September},
ISSN = {0031-9007},
url = {http://dx.doi.org/10.1103/physrevlett.103.117002},
Abstract = {Superconductivity was recently found in the tetragonal phase
FeSe. A structural transformation from tetragonal to
orthorhombic (or monoclinic, depending on point of view) was
observed at low temperature, but was not accompanied by a
magnetic ordering as commonly occurs in the parent compounds
of FeAs-based superconductors. Here, we report the
correlation between structural distortion and
superconductivity in FeSe(1-x) thin films with different
preferred growth orientations. The films with preferred
growth along the c axis show a strong thickness dependent
suppression of superconductivity and low temperature
structural distortion. In contrast, both properties are less
affected in the films with (101) preferred orientation.
These results suggest that the low temperature structural
distortion is closely associated with the superconductivity
of this material.},
Doi = {10.1103/physrevlett.103.117002},
Key = {fds245796}
}
@article{fds245797,
Author = {Chang, AM and Chen, JC},
Title = {The Kondo effect in coupled-quantum dots},
Journal = {Reports on Progress in Physics},
Volume = {72},
Number = {9},
Pages = {096501-096501},
Publisher = {IOP Publishing},
Year = {2009},
Month = {November},
ISSN = {0034-4885},
url = {http://dx.doi.org/10.1088/0034-4885/72/9/096501},
Abstract = {We discuss Kondo systems in coupled-quantum dots, with
emphasis on the semiconductor quantum dot system. The rich
variety of behaviors, such as distinct quantum phases,
non-Fermi-liquid behavior and associated quantum phase
transitions and cross-over behaviors are reviewed.
Experimental evidence for such novel characteristics is
summarized. The observed behaviors may provide clues as to
the relevance of the 2-impurity Kondo (2IK) effect and the
2-channel Kondo (2CK) effect to the unusual characteristics
in strongly correlated systems, such as the heavy fermion
system. © 2009 IOP Publishing Ltd.},
Doi = {10.1088/0034-4885/72/9/096501},
Key = {fds245797}
}
@article{fds245793,
Author = {Wang, L-J and Guo, GP and Wei, D and Cao, G and Tu, T and Xiao, M and Guang-Can, G and Chang, AM},
Title = {Gates controlled parallel-coupled double quantum dot on both
single layer and bilayer graphene},
Journal = {Applied Physics Letters},
Volume = {99},
Number = {11},
Pages = {112117},
Publisher = {AIP Publishing},
Year = {2011},
ISSN = {0003-6951},
url = {http://apl.aip.org/resource/1/applab/v99/i11/p112117_s1?isAuthorized=no},
Abstract = {Here we report the fabrication and quantum transport
measurements of gates controlled parallel-coupled double
quantum dot on both bilayer and single layer graphene. It is
shown that the interdot coupling strength of the parallel
double dots can be effectively tuned from weak to strong
regime by both the in-plane plunger gates and back gate. All
the relevant energy scales and parameters of the graphene
parallel-coupled double dot can be extracted from the
honeycomb charge stability diagrams revealed through the
transport measurements. The present method of designing and
fabricating graphene parallel DQD is demonstrated to be
general and reliable, which may greatly enhance the
realization of graphene nanodevice and desirable study of
rich parallel DQD physical phenomena in graphene.},
Doi = {10.1063/1.3638471},
Key = {fds245793}
}
@article{fds245795,
Author = {Li, P and Wu, PM and Bomze, Y and Borzenets, IV and Finkelstein, G and Chang, AM},
Title = {Switching currents limited by single phase slips in
one-dimensional superconducting Al nanowires.},
Journal = {Physical Review Letters},
Volume = {107},
Number = {13},
Pages = {137004},
Year = {2011},
Month = {September},
url = {http://www.ncbi.nlm.nih.gov/pubmed/22026893},
Abstract = {An aluminum nanowire switches from superconducting to normal
as the current is increased in an upsweep. The switching
current (I(s)) averaged over upsweeps approximately follows
the depairing critical current (I(c)) but falls below it.
Fluctuations in I(s) exhibit three distinct regions of
behaviors and are nonmonotonic in temperature: saturation
well below the critical temperature T(c), an increase as
T(2/3) at intermediate temperatures, and a rapid decrease
close to T(c). Heat dissipation analysis indicates that a
single phase slip is able to trigger switching at low and
intermediate temperatures, whereby the T(2/3) dependence
arises from the thermal activation of a phase slip, while
saturation at low temperatures provides striking evidence
that the phase slips by macroscopic quantum
tunneling.},
Doi = {10.1103/physrevlett.107.137004},
Key = {fds245795}
}
@article{fds245794,
Author = {Li, P and Wu, PM and Bomze, Y and Borzenets, IV and Finkelstein, G and Chang, AM},
Title = {Retrapping current, self-heating, and hysteretic
current-voltage characteristics in ultranarrow
superconducting aluminum nanowires},
Journal = {Physical Review B},
Volume = {84},
Number = {18},
Pages = {184508},
Publisher = {American Physical Society (APS)},
Year = {2011},
Month = {November},
ISSN = {1098-0121},
url = {http://prb.aps.org/abstract/PRB/v84/i18/e184508},
Abstract = {Hysteretic I-V (current-voltage) curves are studied in
narrow Al nanowires. The nanowires have a cross section as
small as 50 nm2. We focus on the retrapping current in a
down-sweep of the current, at which a nanowire re-enters the
superconducting state from a normal state. The retrapping
current is found to be significantly smaller than the
switching current at which the nanowire switches into the
normal state from a superconducting state during a current
up-sweep. For wires of different lengths, we analyze the
heat removal due to various processes, including electron
and phonon processes. For a short wire 1.5μm in length,
electronic thermal conduction is effective; for longer wires
10μm in length, phonon conduction becomes important. We
demonstrate that the measured retrapping current as a
function of temperature can be quantitatively accounted for
by the self-heating occurring in the normal portions of the
nanowires to better than 20% accuracy. For the phonon
processes, the extracted thermal conduction parameters
support the notion of a reduced phase-space below three
dimensions, consistent with the phonon thermal wavelength
having exceeded the lateral dimensions at temperatures below
∼1.3 K. Nevertheless, surprisingly the best fit was
achieved with a functional form corresponding to
three-dimensional phonons, albeit requiring parameters far
exceeding known values in the literature. © 2011 American
Physical Society.},
Doi = {10.1103/PhysRevB.84.184508},
Key = {fds245794}
}
@article{fds245787,
Author = {Wang, LJ and Li, HO and Tu, T and Cao, G and Zhou, C and Hao, XJ and Su, Z and Xiao, M and Guo, GC and Chang, AM and Guo, GP},
Title = {Controllable tunnel coupling and molecular states in a
graphene double quantum dot},
Journal = {Applied Physics Letters},
Volume = {100},
Number = {2},
Pages = {022106-022106},
Publisher = {AIP Publishing},
Year = {2012},
Month = {January},
ISSN = {0003-6951},
url = {http://dx.doi.org/10.1063/1.3676083},
Abstract = {We have measured a graphene double quantum dot device with
multiple electrostatic gates that are used to enhance
control to investigate it. At low temperatures, the
transport measurements reveal honeycomb charge stability
diagrams which can be tuned from weak to strong interdot
tunnel coupling regimes. We precisely extract a large
interdot tunnel coupling strength for this system allowing
for the observation of tunnel-coupled molecular states
extending over the whole double dot. This clean, highly
controllable system serves as an essential building block
for quantum devices in a nuclear-spin-free world. © 2012
American Institute of Physics.},
Doi = {10.1063/1.3676083},
Key = {fds245787}
}
@article{fds245791,
Author = {Wu, PM and Li, P and Zhang, H and Chang, AM},
Title = {Evidence for the formation of quasibound states in an
asymmetrical quantum point contact},
Journal = {Physical Review B},
Volume = {85},
Number = {8},
Pages = {085305},
Publisher = {American Physical Society (APS)},
Year = {2012},
Month = {February},
ISSN = {1098-0121},
url = {http://dx.doi.org/10.1103/PhysRevB.85.085305},
Abstract = {Features below the first conductance plateau in ballistic
quantum point contacts (QPCs) are often ascribed to electron
interaction and spin effects within the single mode limit.
In QPCs with a highly asymmetric geometry, we observe sharp
resonance peaks when the point contacts are gated to the
single mode regime, and surprisingly, under certain gating
conditions, a complete destruction of the 2e2/h first
quantum plateau. The temperature evolution of the resonances
suggest non-Fermi-liquid behavior, while the overall
nonlinear characterizations reveal features reminiscent of
the 0.7 effect. We attribute these unusual behaviors to the
formation of a quasibound state, which is stabilized by a
momentum mismatch accentuated by asymmetry. © 2012 American
Physical Society.},
Doi = {10.1103/PhysRevB.85.085305},
Key = {fds245791}
}
@article{fds245792,
Author = {Chang, AM and Zhang, H and Pfeiffer, LN and West,
KW},
Title = {Fabrication of submicron devices on the (011) cleave surface
of a cleaved-edge-overgrowth GaAs/AlGaAs
crystal},
Journal = {Applied Physics Letters},
Volume = {100},
Number = {12},
Pages = {123106-123106},
Publisher = {AIP Publishing},
Year = {2012},
Month = {March},
ISSN = {0003-6951},
url = {http://dx.doi.org/10.1063/1.3694052},
Abstract = {We describe the fabrication of submicron devices on the
(011) cleave surface of a GaAs heterostructure crystal, in
which this surface is extremely narrow. Special purpose
devices are produced, which take advantage of the unique
characteristics of cleaved-edge-overgrowth. The successful
fabrication relies on understanding the surface tension of
the electron beam polymethyl methacrylate resist, the
workable degree of variation in resist thickness, and on
gluing the crystal onto a backing substrate to increase
structural strength. We demonstrate functional
gate-controlled quantum point contact constrictions placed 9
m from one edge of the cleave surface. © 2012 American
Institute of Physics.},
Doi = {10.1063/1.3694052},
Key = {fds245792}
}
@article{fds245790,
Author = {Zhang, H and Wu, PM and Chang, AM},
Title = {Quasibound States and Evidence for a Spin 1 Kondo Effect in
Asymmetric Quantum Point Contacts},
Journal = {Physical Review B},
Volume = {88},
Number = {7},
Pages = {075311},
Publisher = {American Physical Society (APS)},
Year = {2013},
url = {http://dx.doi.org/10.1103/PhysRevB.88.075311},
Abstract = {Linear conductance below 2e2/h shows resonance peaks in
highly asymmetric quantum point contacts (QPCs). As the
channel length increases, the number of peaks also
increases. At the same time, differential conductance
exhibits zero bias anomalies (ZBAs) in correspondence with
every other peak in the linear conductance. This even odd
effect, observable in the longer channels, is consistent
with the formation of quasi-localized states within the QPC.
In rare cases, triple peaks are observed, indicating the
formation of a spin one Kondo effect when the electron
filling number is even. Changing the gate voltage tunes this
spin triplet to a singlet which exhibits no ZBA. The
triple-peak provides the first evidence suggestive of a spin
singlet triplet transition in a QPC, and the presence of a
ferromagnetic spin interaction between electrons.},
Doi = {10.1103/PhysRevB.88.075311},
Key = {fds245790}
}
@book{fds245761,
Author = {Altomare, F and Chang, AM},
Title = {One-Dimensional Superconductivity in Nanowires},
Booktitle = {One-Dimensional Superconductivity in Nanowires},
Publisher = {Wiley-VCH},
Year = {2013},
Month = {April},
ISBN = {9783527409952},
url = {http://dx.doi.org/10.1002/9783527649044},
Abstract = {The book introduces scientists and graduate students to
superconductivity, and highlights the differences arising
from the different dimensionality of the sample under study.
It focuses on transport in one-dimensional superconductors,
describing relevant theories with particular emphasis on
experimental results. It closely relates these results to
the emergence of various novel fabrication techniques. The
book closes by discussing future perspectives, and the
connection and relevance to other physical systems,
including superfluidity, Bose-Einstein condensates, and
possibly cosmic strings. © 2013 Wiley-VCH Verlag GmbH & Co.
KGaA. All rights reserved.},
Doi = {10.1002/9783527649044},
Key = {fds245761}
}
@article{fds225724,
Author = {Hao Zhang and Phillip M. Wu and A. M. Chang},
Title = {Novel Differential Conductance Oscillations in Asymmetric
Quantum Point Contacts},
Journal = {Physical Review Letters},
Year = {2014},
Abstract = {Small differential conductance oscillations as a function of
source-drain bias were observed and systematically studied
in an asymmetric quantum point contact (QPC). These
oscillations become significantly suppressed in a small
in-plane magnetic field (~ 0.7T) or at higher temperatures
(800mK). Qualitatively, their temperature evolution can be
simulated numerically based on smearing of the Fermi
distribution, whereas features near zero-bias cannot.
Several simple single particle pictures have been considered
and ruled out to interpret these oscillations, which
suggests that these oscillations may be related to electron
and spin correlations.},
Key = {fds225724}
}
@article{fds225725,
Author = {Runan Shang and Hai-Ou Li and Gang Cao and Guodong Yu and Ming Xiao and Tao
Tu, Guang-Can Guo and Hongwen Jiang and A.M.Chang and Guo-Ping
Guo},
Title = {Observation of the Kondo Effect in a Quadruple-Quantum-Dots},
Journal = {Physical Review Letters},
Year = {2014},
Abstract = {We investigate the Kondo effect in a quadruple quantum dot
device of coupled-double quantum dots (DQDs), which
simultaneously contains intra-DQDs and inter-DQDs coupling.
A variety of novel behaviors are observed. The differential
conductance dI/dV is measured in the upper DQDs as a
function of source drain bias. It is found to exhibit
multiple peaks, including a zero-bias peak, where the number
of peaks exceeds five. Alternatively, tuning the lower DQDs
yielded regions of four peaks. In addition, a Kondo-effect
switcher is demonstrated, using the lower DQDs as the
controller.},
Key = {fds225725}
}
@article{fds245760,
Author = {Zhang, H and Wu, PM and Chang, AM},
Title = {Differential conductance oscillations in asymmetric quantum
point contacts},
Journal = {Physical Review B},
Volume = {91},
Number = {19},
Publisher = {American Physical Society (APS)},
Year = {2015},
Month = {May},
ISSN = {1098-0121},
url = {http://dx.doi.org/10.1103/PhysRevB.91.195150},
Abstract = {Small differential conductance oscillations as a function of
source-drain bias are observed and systematically studied in
an asymmetric quantum point contact. These oscillations
become significantly suppressed in a small in-plane magnetic
field (∼0.7 T) or at higher temperatures (∼800 mK).
Qualitatively, their temperature evolution can be simulated
numerically based on smearing of the Fermi distribution,
whereas features near zero bias cannot. Single-particle
scenarios are unsatisfactory in accounting for the
oscillations, suggesting that they are likely caused by
electron- and spin-correlation effects.},
Doi = {10.1103/PhysRevB.91.195150},
Key = {fds245760}
}
@article{fds245759,
Author = {Shang, R and Li, HO and Cao, G and Yu, G and Xiao, M and Tu, T and Guo, GC and Jiang, H and Chang, AM and Guo, GP},
Title = {Observation of the Kondo effect in a quadruple quantum
dot},
Journal = {Physical Review B},
Volume = {91},
Number = {24},
Publisher = {American Physical Society (APS)},
Year = {2015},
Month = {June},
ISSN = {1098-0121},
url = {http://hdl.handle.net/10161/11138 Duke open
access},
Abstract = {We investigate the Kondo effect in a quadruple-quantum-dot
device of coupled double quantum dots (DQDs), which
simultaneously contain intra-DQD and inter-DQD coupling. A
variety of novel behaviors are observed. The differential
conductance dI/dV is measured in the upper DQDs as a
function of source drain bias. It is found to exhibit
multiple peaks, including a zero-bias peak, where the number
of peaks exceeds five. Alternatively, tuning the lower DQDs
yielded regions of four peaks. In addition, a Kondo effect
switcher is demonstrated, using the lower DQDs as the
controller.},
Doi = {10.1103/PhysRevB.91.245102},
Key = {fds245759}
}
@article{fds303657,
Author = {Bove, A and Altomare, F and Kundtz, N and Chang, AM and Cho, YJ and Liu, X and Furdyna, J},
Title = {A novel technique to make Ohmic contact to a buried
two-dimensional electron gas in a molecular-beam-epitaxy
grown GaAs/Al0.3Ga0.7As heterostructure with Mn
δ-doping},
Publisher = {Cornell University Library},
Year = {2015},
Month = {October},
url = {arxiv:0802.3863},
Key = {fds303657}
}
@article{fds303658,
Author = {Bove, A and Altomare, F and Kundtz, N and Chang, AM and Cho, AM and Liu, X and Furdyna, J},
Title = {Electron-mediated ferromagnetism and small spin-orbit
interaction in molecular-beam-epitaxy grown n-type
GaAs/Al0.3Ga0.7As heterostructures with Mn
δ-doping},
Publisher = {Cornell University Library},
Year = {2015},
Month = {October},
url = {arxiv:0802.3871},
Key = {fds303658}
}
@article{fds342552,
Author = {Cao, L and Altomare, F and Guo, H and Feng, M and Chang,
AM},
Title = {Coulomb blockade correlations in a coupled single-electron
device system},
Journal = {Solid State Communications},
Volume = {296},
Pages = {12-16},
Year = {2019},
Month = {July},
url = {http://dx.doi.org/10.1016/j.ssc.2019.04.004},
Abstract = {Single-electron devices, such as metal single-electron
transistor (SET) and semiconductor quantum dot (QD), are
Coulomb blockade (CB) devices with promising applications in
both quantum and classical beyond-Si information
technologies. As an example, a coupled SET-QD system can
provide an experimental platform for addressing,
manipulating, and detecting spin and/or charge-based qubits
for quantum information processing. We have designed and
fabricated a prototype device in this family: a
series-coupled double quantum dot (DQD) with side-coupled
and/or top-coupled Al single-electron transistors (Al-SET),
and implemented the readout of the single electron charging
and CB behaviors in a QD using the Al-SET. The readout
operation is manifested by the correlated CB oscillations
taking place separately in the SET and in the QD; these
oscillations originate from that the change of electrons one
by one in the QD. We have developed an electrostatics model
to study the CB correlations in the capacitively coupled
QD/Al-SET device system, which shows qualitative agreement
with our experimental observations. Moreover, our design and
device fabrication are compatible with modern semiconductor
techniques, and can potentially be scaled up into larger
integrated systems with quantum and classic bit operation
and measurement circuitry.},
Doi = {10.1016/j.ssc.2019.04.004},
Key = {fds342552}
}