%% Books
@book{fds167377,
Author = {Luis Bonilla and Stephen Teitsworth},
Title = {Nonlinear wave methods for electronic transport in condensed
matter systems},
Publisher = {Wiley - VCF},
Year = {2010},
Key = {fds167377}
}
%% Papers Published
@booklet{Delacruz93,
Author = {Dela Cruz and RM and Teitsworth, SW and Stroscio,
MA},
Title = {Bottleneck effects due to confined phonons in quantum
dots},
Journal = {Superlattices and Microstructures},
Volume = {13},
Number = {4},
Pages = {481-486},
Publisher = {Elsevier BV},
Year = {1993},
Month = {January},
ISSN = {0749-6036},
url = {http://dx.doi.org/10.1006/spmi.1993.1090},
Abstract = {A generalization of the three-dimensional Fröhlich
hamiltonian for a polar semiconductor is presented which
describes the interaction between charge carriers of a
zero-dimensional electron gas and longitudinal optical (LO)
phonon modes confined in three spatial dimensions. This
hamiltonian is used to calculate the scattering rate of
electrons by LO phonons in a GaAs quantum box which is
free-standing in vacuum. The suppression of scattering
through a phonon bottleneck effect is discussed in terms of
the selection rules. © 1993 Academic Press. All rights
reserved.},
Doi = {10.1006/spmi.1993.1090},
Key = {Delacruz93}
}
@booklet{Teitsworth84,
Author = {Teitsworth, SW and Westervelt, RM},
Title = {Chaos and broadband noise in extrinsic photoconductors},
Journal = {Physical Review Letters},
Volume = {53},
Number = {27},
Pages = {2587-2590},
Publisher = {American Physical Society (APS)},
Year = {1984},
Month = {January},
ISSN = {0031-9007},
url = {http://dx.doi.org/10.1103/PhysRevLett.53.2587},
Abstract = {A simple model is studied describing low-temperature
free-carrier dynamics in extrinsic photoconductors due to
capture by impurity atoms and impact ionization. Numerical
results are presented which exhibit period doubling, chaotic
behavior, and elevated effective noise temperatures.
Photoconductor properties necessary for chaotic behavior are
discussed. © 1984 The American Physical
Society.},
Doi = {10.1103/PhysRevLett.53.2587},
Key = {Teitsworth84}
}
@booklet{Teitsworth86,
Author = {Teitsworth, SW and Lynn, BA and Westervelt, RM},
Title = {Chaotic dynamics in a simple model of extrinsic
photoconductors},
Journal = {Physica Scripta},
Volume = {1986},
Number = {T14},
Pages = {71-75},
Publisher = {IOP Publishing},
Year = {1986},
Month = {January},
ISSN = {0281-1847},
url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:A1986H841100014&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
Abstract = {We have studied the nonlinear dynamical properties of a
simple periodicallydriven rate equation model describing
electrical conduction in extrinsic photoconductors.
Extensive numerical simulations analysed using phase
portraits, Poincart sections, approximate one-dimensional
mappings, and nonlinear phase diagrams show a range of
nonlinear dynamical behavior including chaotic oscillation,
transitions to intermittently chaotic oscillation, and phase
locking behavior for large drive amplitudes. In addition, we
have fully explored the strong dependence of observed
nonlinear dynamical behavior on parameter variation in the
model. © 1986 IOP Publishing Ltd.},
Doi = {10.1088/0031-8949/1986/T14/012},
Key = {Teitsworth86}
}
@article{fds340359,
Author = {Westervelt, RM and Gwinn, EG and Teitsworth, SW},
Title = {Chaotic dynamics in Ge photoconductors},
Journal = {Nuclear Physics B (Proceedings Supplements)},
Volume = {2},
Number = {C},
Pages = {37-48},
Publisher = {Elsevier BV},
Year = {1987},
Month = {January},
url = {http://dx.doi.org/10.1016/0920-5632(87)90007-7},
Abstract = {Experimental tests are presented of universal predictions of
the circle map for the response of driven nonlinear
oscillators, using a spatio-temporal instability associated
with impurity impact ionization in liquid He cooled p-type
Ge. Both the measured power spectrum and the spectrum of
dimensions f (α) for drive at the critical amplitude for
winding number equal to the golden mean are found to be in
quantitative agreement with theory. © 1987.},
Doi = {10.1016/0920-5632(87)90007-7},
Key = {fds340359}
}
@booklet{Westervelt86,
Author = {Westervelt, RM and Teitsworth, SW and Gwinn, EG},
Title = {Chaotic dynamics in ge photoconductors},
Journal = {Physica Scripta},
Volume = {1986},
Number = {T14},
Pages = {65-70},
Publisher = {IOP Publishing},
Year = {1986},
Month = {January},
ISSN = {0281-1847},
url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:A1986H841100013&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
Abstract = {Two sets of experimental results are given to demonstrate
how modern nonlinear dynamics can be used to understand the
dynamics of extrinsic Ge photoconductors. In the first, we
show how complex and apparently random chaotic broadband
noise is physically produced in devices which have nearly
ideal stochastic noise performance in the absence of drive.
In the second, we demonstrate that the circle map, a simple
model of periodically-driven active oscillators with
universal predictions, quantitatively describes the dynamics
of a driven spatially-dependent high field instability in
Ge. © 1986 IOP Publishing Ltd.},
Doi = {10.1088/0031-8949/1986/T14/011},
Key = {Westervelt86}
}
@article{fds248441,
Author = {Cantalapiedra, IR and Bergmann, MJ and Bonilla, LL and Teitsworth,
SW},
Title = {Chaotic motion of space charge wave fronts in semiconductors
under time-independent voltage bias},
Journal = {Physical Review E - Statistical, Nonlinear, and Soft Matter
Physics},
Volume = {63},
Number = {5 II},
Pages = {562161-562167},
Year = {2001},
url = {http://arxiv.org/abs/cond-mat/0011162v1},
Abstract = {The chaos under dc voltage bias linked with multiple
shedding of wave fronts were numerically simulated. Space
charge wave dynamics was analyzed with a finite-dimensional
model. Drift diffusion model of space charge wave
propagation in semiconductors was studied. The dynamics of
space charge waves and current vs time were explained by
asymptotic analysis of a partial differential equation
model. It was found that single or multiple wave shedding
during each oscillation depend on resistivity of the
injecting contacts.},
Doi = {10.1103/physreve.63.056216},
Key = {fds248441}
}
@article{fds4222,
Author = {K. J. Luo and S.W. Teitsworth and M. Rogozia and H. T. Grahn and L.
Bonilla, J. Galan and N. Ohtani},
Title = {Controllable bifurcation processes in undoped, photoexcited
GaAs/AlAs superlattices},
Series = {World Scientific},
Booktitle = {Proceedings of the 5th experimental chaos
conference},
Editor = {M. Ding et al.},
Year = {2001},
Key = {fds4222}
}
@article{fds248489,
Author = {Luo, KJ and Teitsworth, SW and Kostial, H and Grahn, HT and Ohtani,
N},
Title = {Controllable bistabilities and bifurcations in a
photoexcited GaAs/AlAs superlattice},
Journal = {Applied Physics Letters},
Volume = {74},
Number = {25},
Pages = {3845-3847},
Publisher = {AIP Publishing},
Year = {1999},
Month = {June},
url = {http://dx.doi.org/10.1063/1.124199},
Abstract = {Self-sustained photocurrent oscillations and bifurcation
process have been demonstrated on an undoped photoexcited
GaAs/AlAs superlattice. The effects of carrier density,
varied by changing the laser intensity, on the transition
between static and oscillating domains are investigated.
Within a certain range of intermediate intensities, the
time-average photocurrent vs voltage plot exhibits a
controllable bistability region near the edge of the first
photocurrent plateau and the oscillations disappear via a
subcritical Hopf bifurcation (HB) with increasing DC bias.
Below this range, the oscillations disappear via a
supercritical HB, while above it, a homoclinic connection is
observed.},
Doi = {10.1063/1.124199},
Key = {fds248489}
}
@booklet{Blue97,
Author = {Blue, LJ and Daniels-Race, T and Kendall, RE and Schmid, CR and Teitsworth, SW},
Title = {Dependence of current-voltage characteristics on Al mole
fraction in GaAs/AlxGa1-xAs asymmetric
double barrier structures},
Journal = {Journal of Vacuum Science and Technology B: Microelectronics
and Nanometer Structures},
Volume = {15},
Number = {3},
Pages = {696-701},
Publisher = {American Vacuum Society},
Year = {1997},
Month = {May},
url = {http://dx.doi.org/10.1116/1.589371},
Abstract = {The effect of barrier Al mole fraction, 0.2≤x≤0.8. on
tunneling currents has been studied for a set of asymmetric
GaAs/AlxGa1-xAs double barrier structures. The barrier
widths of each sample were scaled so that barrier
transmission coefficients for different samples should be
approximately equivalent at the first resonant tunneling
peak. Structures were grown by molecular beam epitaxy; by
adjusting Ga and Al cell temperatures, the full range of Al
mole fractions could be achieved in AlxGa1-xAs barrier
layers while maintaining a nearly constant growth rate of
about 1 μm/h. Current-voltage measurements are in agreement
with theoretical estimates and indicate good sample quality.
© 1997 American Vacuum Society.},
Doi = {10.1116/1.589371},
Key = {Blue97}
}
@article{fds304623,
Author = {Xu, H and Teitsworth, SW},
Title = {Dependence of electric field domain relocation dynamics on
contact conductivity in semiconductor superlattices},
Journal = {Physical Review B - Condensed Matter and Materials
Physics},
Volume = {76},
Number = {23},
Publisher = {American Physical Society (APS)},
Year = {2007},
Month = {December},
ISSN = {1098-0121},
url = {http://dx.doi.org/10.1103/PhysRevB.76.235302},
Abstract = {Numerical simulation results are presented for a discrete
drift-diffusion rate equation model that describes
electronic transport due to sequential tunneling between
adjacent quantum wells in weakly coupled semiconductor
superlattices. We study the dependence on contact
conductivity σ of current-voltage characteristics and
transient current response to abrupt steps in applied
voltage. For intermediate values of σ, three qualitatively
distinct transient responses-each associated with a
different mechanism for the relocation of a static charge
accumulation layer-are observed for different values of
voltage step Vstep; these involve, respectively, (1) the
motion of a single charge accumulation layer, (2) the motion
of an injected charge dipole, and (3) the motion of an
injected monopole. A critical value of σ is identified
above which the injected dipole mechanism is not observed
for any value of Vstep. Furthermore, at very low σ, we find
a reversed static field configuration, i.e., with the
high-field domain adjacent to the emitter contact. © 2007
The American Physical Society.},
Doi = {10.1103/PhysRevB.76.235302},
Key = {fds304623}
}
@article{fds248453,
Author = {Xu, H and Teitsworth, SW},
Title = {Dependence of electric field domain relocation dynamics on
contact conductivity in semiconductor superlattices},
Journal = {Physical Review B},
Volume = {76},
Number = {235302},
Pages = {11 pages},
Year = {2007},
ISSN = {1098-0121},
url = {http://dx.doi.org/10.1103/PhysRevB.76.235302},
Abstract = {Numerical simulation results are presented for a discrete
drift-diffusion rate equation model that describes
electronic transport due to sequential tunneling between
adjacent quantum wells in weakly coupled semiconductor
superlattices. We study the dependence on contact
conductivity σ of current-voltage characteristics and
transient current response to abrupt steps in applied
voltage. For intermediate values of σ, three qualitatively
distinct transient responses—each associated with a
different mechanism for the relocation of a static charge
accumulation layer—are observed for different values of
voltage step Vstep; these involve, respectively, (1) the
motion of a single charge accumulation layer, (2) the motion
of an injected charge dipole, and (3) the motion of an
injected monopole. A critical value of σ is identified
above which the injected dipole mechanism is not observed
for any value of Vstep. Furthermore, at very low σ, we find
a reversed static field configuration, i.e., with the
high-field domain adjacent to the emitter
contact.},
Doi = {10.1103/PhysRevB.76.235302},
Key = {fds248453}
}
@article{fds304624,
Author = {Xu, H and Amann, A and Schöll, E and Teitsworth,
SW},
Title = {Dynamics of electronic transport in a semiconductor
superlattice with a shunting side layer},
Journal = {Physical Review B - Condensed Matter and Materials
Physics},
Volume = {79},
Number = {24},
Publisher = {American Physical Society (APS)},
Year = {2009},
Month = {June},
ISSN = {1098-0121},
url = {http://dx.doi.org/10.1103/PhysRevB.79.245318},
Abstract = {We study a model describing electronic transport in a weakly
coupled semiconductor superlattice with a shunting side
layer. Key parameters include the lateral size of the
superlattice, the connectivity between the quantum wells of
the superlattice and the shunt layer, and the conduction
properties of the shunt layer. For a superlattice with small
lateral extent and high quality shunt, static electric field
domains are suppressed and a spatially uniform field
configuration is predicted to be stable, results that may be
useful for proposed devices such as a superlattice-based
terahertz oscillators. As the lateral size of the
superlattice increases, the uniform field configuration
loses its stability to either static or dynamic field
domains regardless of shunt properties. A lower quality
shunt generally leads to regular and chaotic current
oscillations and complex spatiotemporal dynamics in the
field profile. Bifurcations separating static and dynamic
behaviors are characterized and found to be dependent on the
shunt properties. © 2009 The American Physical
Society.},
Doi = {10.1103/PhysRevB.79.245318},
Key = {fds304624}
}
@article{fds248456,
Author = {Xu, H and Amann, A and Schoell, E and Teitsworth,
SW},
Title = {Dynamics of electronic transport in a semiconductor
superlattice with a shunting side layer},
Journal = {Physical Review B},
Volume = {79},
Number = {245318},
Pages = {14},
Year = {2009},
ISSN = {1098-0121},
url = {http://dx.doi.org/10.1103/PhysRevB.79.245318},
Abstract = {We study a model describing electronic transport in a weakly
coupled semiconductor superlattice with a shunting side
layer. Key parameters include the lateral size of the
superlattice, the connectivity between the quantum wells of
the superlattice and the shunt layer, and the conduction
properties of the shunt layer. For a superlattice with small
lateral extent and high quality shunt, static electric field
domains are suppressed and a spatially uniform field
configuration is predicted to be stable, results that may be
useful for proposed devices such as a superlattice-based
terahertz oscillators. As the lateral size of the
superlattice increases, the uniform field configuration
loses its stability to either static or dynamic field
domains regardless of shunt properties. A lower quality
shunt generally leads to regular and chaotic current
oscillations and complex spatiotemporal dynamics in the
field profile. Bifurcations separating static and dynamic
behaviors are characterized and found to be dependent on the
shunt properties.},
Doi = {10.1103/PhysRevB.79.245318},
Key = {fds248456}
}
@booklet{Kim92,
Author = {Kim, KW and Bhatt, AR and Stroscio, MA and Turley, PJ and Teitsworth,
SW},
Title = {Effects of interface phonon scattering in
multiheterointerface structures},
Journal = {Journal of Applied Physics},
Volume = {72},
Number = {6},
Pages = {2282-2287},
Publisher = {AIP Publishing},
Year = {1992},
Month = {December},
ISSN = {0021-8979},
url = {http://dx.doi.org/10.1063/1.351569},
Abstract = {In this paper, the commonly used but idealistic formulation
of quantized optical-phonon modes for a heterostructure
system with only two heterojunctions (i.e., single
quantum-well structures) is extended to the more realistic
case of multiheterointerface structures. By applying the
macroscopic dielectric continuum approach, dispersion
relations and interaction Hamiltonians for interface-phonon
modes are derived for a double-barrier structure and
scattering rates based on these results are used to
determine the range of practical validity of the idealistic
model using interaction Hamiltonians appropriate for single
quantum wells with infinite barrier widths. It is found that
when the dimensions of the structures are larger than
approximately 30 Å, this simplified description can be
applied to multiheterointerface structures in general with
reasonable accuracy.},
Doi = {10.1063/1.351569},
Key = {Kim92}
}
@booklet{Turley91,
Author = {Turley, PJ and Teitsworth, SW},
Title = {Effects of localized phonon modes on magnetotunneling
spectra in double-barrier structures.},
Journal = {Physical review. B, Condensed matter},
Volume = {44},
Number = {23},
Pages = {12959-12963},
Year = {1991},
Month = {December},
ISSN = {0163-1829},
url = {http://www.ncbi.nlm.nih.gov/pubmed/9999478},
Doi = {10.1103/physrevb.44.12959},
Key = {Turley91}
}
@booklet{Turley91b,
Author = {Turley, PJ and Teitsworth, SW},
Title = {Electronic wave functions and electron-confined-phonon
matrix elements in GaAs/AlxGa1-xAs double-barrier
resonant-tunneling structures.},
Journal = {Physical review. B, Condensed matter},
Volume = {44},
Number = {7},
Pages = {3199-3210},
Year = {1991},
Month = {August},
ISSN = {0163-1829},
url = {http://www.ncbi.nlm.nih.gov/pubmed/9999916},
Doi = {10.1103/physrevb.44.3199},
Key = {Turley91b}
}
@article{fds248449,
Author = {Xu, H and Teitsworth, SW},
Title = {Emergence of current branches in a series array of negative
differential resistance circuit elements},
Journal = {Journal of Applied Physics},
Volume = {108},
Number = {4},
Pages = {043705-043705},
Publisher = {AIP Publishing},
Year = {2010},
Month = {August},
ISSN = {0021-8979},
url = {http://arxiv.org/abs/1006.0434v1},
Abstract = {We study a series array of nonlinear electrical circuit
elements that possess negative differential resistance and
find that heterogeneity in the element properties leads to
the presence of multiple branches in current-voltage curves
and a nonuniform distribution of voltages across the
elements. An inhomogeneity parameter rmax is introduced to
characterize the extent to which the individual element
voltages deviate from one another, and it is found to be
strongly dependent on the rate of change of applied voltage.
Analytical expressions are derived for the dependence of
rmax on voltage ramping rate in the limit of fast ramping
and are confirmed by direct numerical simulation. © 2010
American Institute of Physics.},
Doi = {10.1063/1.3475988},
Key = {fds248449}
}
@article{fds341883,
Author = {Gonzalez, JP and Neu, JC and Teitsworth, SW},
Title = {Experimental metrics for detection of detailed balance
violation.},
Journal = {Physical review. E},
Volume = {99},
Number = {2-1},
Pages = {022143},
Year = {2019},
Month = {February},
url = {http://dx.doi.org/10.1103/physreve.99.022143},
Abstract = {We report on the measurement of detailed balance violation
in a coupled, noise-driven linear electronic circuit
consisting of two nominally identical RC elements that are
coupled via a variable capacitance. The state variables are
the time-dependent voltages across each of the two primary
capacitors, and the system is driven by independent noise
sources in series with each of the resistances. From the
recorded time histories of these two voltages, we quantify
violations of detailed balance by three methods: (1)
explicit construction of the probability current density,
(2) constructing the time-dependent stochastic area, and (3)
constructing statistical fluctuation loops. In comparing the
three methods, we find that the stochastic area is
relatively simple to implement and computationally
inexpensive and provides a highly sensitive means for
detecting violations of detailed balance.},
Doi = {10.1103/physreve.99.022143},
Key = {fds341883}
}
@article{fds325702,
Author = {Ghanta, A and Neu, JC and Teitsworth, S},
Title = {Fluctuation loops in noise-driven linear dynamical
systems.},
Journal = {Physical review. E},
Volume = {95},
Number = {3-1},
Pages = {032128},
Publisher = {American Physical Society (APS)},
Year = {2017},
Month = {March},
url = {http://dx.doi.org/10.1103/physreve.95.032128},
Abstract = {Understanding the spatiotemporal structure of most probable
fluctuation pathways to rarely occurring states is a central
problem in the study of noise-driven, nonequilibrium
dynamical systems. When the underlying system does not
possess detailed balance, the optimal fluctuation pathway to
a particular state and relaxation pathway from that state
may combine to form a looplike structure in the system phase
space called a fluctuation loop. Here, fluctuation loops are
studied in a linear circuit model consisting of coupled RC
elements, where each element is driven by its own
independent noise source. Using a stochastic Hamiltonian
approach, we determine the optimal fluctuation pathways, and
analytically construct corresponding fluctuation loops. To
quantitatively characterize fluctuation loops, we study the
time-dependent area tensor that is swept out by individual
stochastic trajectories in the system phase space. At long
times, the area tensor scales linearly with time, with a
coefficient that precisely vanishes when the system
satisfies detailed balance.},
Doi = {10.1103/physreve.95.032128},
Key = {fds325702}
}
@article{fds304621,
Author = {Lu, SL and Schrottke, L and Teitsworth, SW and Hey, R and Grahn,
HT},
Title = {Formation of electric-field domains in GaAs Alx Ga1-x As
quantum cascade laser structures},
Journal = {Physical Review B - Condensed Matter and Materials
Physics},
Volume = {73},
Number = {3},
Publisher = {American Physical Society (APS)},
Year = {2006},
Month = {February},
ISSN = {1098-0121},
url = {http://dx.doi.org/10.1103/PhysRevB.73.033311},
Abstract = {The current-voltage (I-V) characteristics of GaAs Alx Ga1-x
As quantum cascade laser structures (QCLSs) are found to
exhibit current plateaus with discontinuities for voltages
below threshold. The number of current discontinuities is
correlated with the number of periods of the QCLS,
suggesting the formation of electric-field domains that span
the entire structure. A self-consistent calculation of the
conduction band profile and corresponding electronic wave
functions shows that the low-field domain is related to
resonant tunneling between the ground state g in the active
region and the lowest energy state in the adjacent,
downstream injector i1. For x=0.33 (x=0.45), the high-field
domain is formed for resonant tunneling between g and the
first (second) excited state i2 (i3) in the injector region.
A comparison of the experimental data with the calculated
conduction band profile shows that a significant field
inhomogeneity within each period shifts the voltage range,
for which the resonance condition is fulfilled, to much
lower voltages than expected for a homogeneous field
distribution. © 2006 The American Physical
Society.},
Doi = {10.1103/PhysRevB.73.033311},
Key = {fds304621}
}
@article{fds248457,
Author = {Lu, SL and Schrottke, L and Teitsworth, SW and Hey, R and Grahn,
HT},
Title = {Formation of electric-field domains in GaAs/AlGaAs quantum
cascade laser structures},
Journal = {Physical Review B},
Volume = {73},
Number = {033311},
Pages = {4 pages},
Year = {2006},
Month = {January},
ISSN = {1098-0121},
url = {http://dx.doi.org/10.1103/PhysRevB.73.033311},
Abstract = {The current-voltage (I-V ) characteristics of GaAs/AlGaAs
quantum-cascade laser structures (QCLSs) are found to
exhibit current plateaus with discontinuities for voltages
below threshold. The number of current discontinuities is
correlated with the number of periods of the QCLS,
suggesting the formation of electric-field domains that span
the entire structure. A self-consistent calculation of the
conduction band profile and corresponding electronic wave
functions shows that the low-field domain is related to
resonant tunneling between the ground state g in the active
region and the lowest energy state in the adjacent,
downstream injector i1. For x = 0.33 (x = 0.45), the
high-field domain is formed for resonant tunneling between g
and the first (second) excited state i2 (i3) in the injector
region. A comparison of the experimental data with the
calculated conduction band profile shows that a significant
field inhomogeneity within each period shifts the voltage
range, for which the resonance condition is fulfilled, to
much lower voltages than expected for a homogeneous field
distribution.},
Doi = {10.1103/PhysRevB.73.033311},
Key = {fds248457}
}
@booklet{Wallis94,
Author = {Wallis, CR and Teitsworth, SW},
Title = {Hopf bifurcations and hysteresis in resonant tunneling diode
circuits},
Journal = {Journal of Applied Physics},
Volume = {76},
Number = {7},
Pages = {4443-4445},
Publisher = {AIP Publishing},
Year = {1994},
Month = {December},
ISSN = {0021-8979},
url = {http://dx.doi.org/10.1063/1.357343},
Abstract = {Conditions for Hopf bifurcations and associated current
oscillations are presented for a standard model of a
resonant tunneling diode circuit. We derive a simple
analytic formula for the Hopf bifurcation type (subcritical
or supercritical) and discuss how this affects circuit
operation, e.g., whether or not hysteresis and bistability
are observed in current-voltage curves.},
Doi = {10.1063/1.357343},
Key = {Wallis94}
}
@booklet{Luo98,
Author = {Luo, K and Grahn, H and Teitsworth, S and Ploog, K},
Title = {Influence of higher harmonics on Poincaré maps derived from
current self-oscillations in a semiconductor
superlattice},
Journal = {Physical Review B - Condensed Matter and Materials
Physics},
Volume = {58},
Number = {19},
Pages = {12613-12616},
Publisher = {American Physical Society (APS)},
Year = {1998},
Month = {January},
url = {http://dx.doi.org/10.1103/PhysRevB.58.12613},
Abstract = {The effect of higher harmonics on the shape of Poincaré
maps (first return maps) derived from current
self-oscillations has been investigated in a semiconductor
superlattice system driven by a dc + ac voltage bias. In
addition to the intrinsic fundamental frequency, a number of
higher harmonics with comparable amplitude are observed. The
current oscillation traces are simulated according to the
power spectra in order to determine the effect of the higher
harmonics on the Poincaré maps. The calculated Poincaré
maps for quasiperiodic oscillations as well as frequency
locking are clearly distorted by the presence of the higher
harmonics. The shape of the distorted Poincaré maps agrees
with the experimentally observed ones. The calculation also
reveals that the phase shift between the different frequency
components of the current has an important effect on the
shape of the Poincaré maps. © 1998 The American Physical
Society.},
Doi = {10.1103/PhysRevB.58.12613},
Key = {Luo98}
}
@booklet{Delacruz95,
Author = {de la Cruz RM, and Teitsworth, SW and Stroscio,
MA},
Title = {Interface phonons in spherical GaAs/AlxGa1-xAs quantum
dots.},
Journal = {Physical review. B, Condensed matter},
Volume = {52},
Number = {3},
Pages = {1489-1492},
Year = {1995},
Month = {July},
ISSN = {0163-1829},
url = {http://www.ncbi.nlm.nih.gov/pubmed/9981202},
Doi = {10.1103/physrevb.52.1489},
Key = {Delacruz95}
}
@booklet{Teitsworth94,
Author = {Teitsworth, SW and Turley, PJ and Wallis, CR and Li, W and Bhattacharya,
PK},
Title = {Magnetotunnelling measurements of localized optical phonons
in GaAs/AlAs double-barrier structures},
Journal = {Semiconductor Science and Technology},
Volume = {9},
Number = {5 S},
Pages = {508-511},
Publisher = {IOP Publishing},
Year = {1994},
Month = {December},
ISSN = {0268-1242},
url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:A1994NM75300029&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
Abstract = {We have measured current-voltage characteristics at
liquid-helium temperature and for magnetic fields up to
7T(parallel to the current flow) for three similar
asymmetric GaAs/AlAs double-barrier structures, all of which
possess large phonon-assisted tunnelling currents. Confined
longitudinal optical (LO) phonons in the GaAs well layer and
LO-like symmetric interface phonons treated within a
dielectric continuum picture suffice to account for the
measured currents. Phonon-assisted tunnelling current levels
as well as magnetotunnelling data are found to depend
sensitively on well and barrier widths.},
Doi = {10.1088/0268-1242/9/5S/029},
Key = {Teitsworth94}
}
@article{fds304622,
Author = {Lu, SL and Schrottke, L and Teitsworth, SW and Hey, R and Grahn,
HT},
Title = {Negative differential conductance and bistability in undoped
GaAs/(Al,Ga)As quantum-cascade structures},
Journal = {Journal of Applied Physics},
Volume = {100},
Number = {2},
Pages = {023701-023701},
Publisher = {AIP Publishing},
Year = {2006},
Month = {August},
ISSN = {0021-8979},
url = {http://dx.doi.org/10.1063/1.2214362},
Abstract = {We discuss the mechanisms for negative differential
conductance (NDC) and bistable behavior observed in the
current-density-electric-field (j-F) characteristics of
undoped GaAs/Al 0.45Ga 0.55As quantum-cascade structures
(QCSs). While the j-F characteristic of a QCS with a single
period exhibits NDC without bistability, NDC and a bistable
behavior are observed for a QCS with 20 periods of the same
design. Calculations using a scattering-rate model
neglecting any field inhomogeneities show that the interplay
of resonant tunneling between the states in the QCS with
resonant scattering of longitudinal optical phonons can lead
to NDC in both structures. However, the bistable behavior in
the QCS with 20 periods can only be explained if an
inhomogeneous field distribution due to charge accumulation
is taken into account in addition to the NDC. The abrupt
decrease of the current density at the field strength of the
bistability is attributed to a rapid decrease of the
accumulated charge, which is confirmed by
electric-field-dependent photoluminescence spectroscopy. ©
2006 American Institute of Physics.},
Doi = {10.1063/1.2214362},
Key = {fds304622}
}
@article{fds248458,
Author = {Lu, SL and Schrottke, L and Teitsworth, SW and Hey, R and Grahn,
HT},
Title = {Negative differential conductance and bistability in undoped
GaAs/AlGaAs quantum-cascade structures},
Journal = {Journal of Applied Physics},
Volume = {100},
Number = {023701},
Pages = {6 pages},
Year = {2006},
Month = {July},
ISSN = {0021-8979},
url = {http://dx.doi.org/10.1063/1.2214362},
Abstract = {We discuss the mechanisms for negative differential
conductance NDC and bistable behavior observed in the
current-density–electric-field j-F characteristics of
undoped GaAs/Al0.45Ga0.55As quantum-cascade structures QCSs
. While the j-F characteristic of a QCS with a single period
exhibits NDC without bistability, NDC and a bistable
behavior are observed for a QCS with 20 periods of the same
design. Calculations using a scattering-rate model
neglecting any field inhomogeneities show that the interplay
of resonant tunneling between the states in the QCS with
resonant scattering of longitudinal optical phonons can lead
to NDC in both structures. However, the bistable behavior in
the QCS with 20 periods can only be explained if an
inhomogeneous field distribution due to charge accumulation
is taken into account in addition to the NDC. The abrupt
decrease of the current density at the field strength of the
bistability is attributed to a rapid decrease of the
accumulated charge, which is confirmed by
electric-field-dependent photoluminescence
spectroscopy.},
Doi = {10.1063/1.2214362},
Key = {fds248458}
}
@article{fds248452,
Author = {Bomze, Y and Hey, R and Grahn, HT and Teitsworth,
SW},
Title = {Noise-Induced Current Switching in Semiconductor
Superlattices: Observation of Nonexponential Kinetics in a
High-Dimensional System},
Journal = {Physical Review Letters},
Volume = {109},
Number = {026801},
Pages = {4},
Publisher = {American Physical Society},
Year = {2012},
url = {http://www.ncbi.nlm.nih.gov/pubmed/23030192},
Abstract = {We report on measurements of first-passage-time
distributions associated with current switching in weakly
coupled GaAs/AlAs superlattices driven by shot noise, a
system that is both far from equilibrium and high
dimensional. Static current-voltage (I-V) characteristics
exhibit multiple current branches and bistability;
precision, high-bandwidth current switching data are
collected in response to steps in the applied voltage to
final voltages near the end of a current branch. For a range
of voltage values, the measured switching times vary
stochastically. At short times, the switching time
distributions decay exponentially, while at longer times the
distributions develop nonexponential tails that follow an
approximate power law over several decades. The power law
decay behavior is attributed to the presence of multiple
switching pathways, which may arise from small spatial
variations in the superlattice growth parameters.},
Doi = {10.1103/PhysRevLett.109.026801},
Key = {fds248452}
}
@article{fds304625,
Author = {Bomze, Y and Hey, R and Grahn, HT and Teitsworth,
SW},
Title = {Noise-induced current switching in semiconductor
superlattices: observation of nonexponential kinetics in a
high-dimensional system.},
Journal = {Physical review letters},
Volume = {109},
Number = {2},
Pages = {026801},
Year = {2012},
Month = {July},
url = {http://www.ncbi.nlm.nih.gov/pubmed/23030192},
Abstract = {We report on measurements of first-passage-time
distributions associated with current switching in weakly
coupled GaAs/AlAs superlattices driven by shot noise, a
system that is both far from equilibrium and high
dimensional. Static current-voltage (I-V) characteristics
exhibit multiple current branches and bistability;
precision, high-bandwidth current switching data are
collected in response to steps in the applied voltage to
final voltages V1 near the end of a current branch. For a
range of V1 values, the measured switching times vary
stochastically. At short times (≲10 μs), the
switching time distributions decay exponentially, while at
longer times the distributions develop nonexponential tails
that follow an approximate power law over several decades.
The power law decay behavior is attributed to the presence
of multiple switching pathways, which may arise from small
spatial variations in the superlattice growth
parameters.},
Doi = {10.1103/physrevlett.109.026801},
Key = {fds304625}
}
@booklet{Teitsworth86a,
Author = {Teitsworth, SW and Westervelt, RM},
Title = {Nonlinear current-voltage characteristics and spontaneous
current oscillations in p-Ge},
Journal = {Physica D: Nonlinear Phenomena},
Volume = {23},
Number = {1-3},
Pages = {181-186},
Publisher = {Elsevier BV},
Year = {1986},
Month = {January},
ISSN = {0167-2789},
url = {http://dx.doi.org/10.1016/0167-2789(86)90126-0},
Abstract = {We report an experimental measurement of nonlinear dc
current-voltage (I-V) characteristics in p-type Ge extrinsic
photoconductors at liquid He temperatures which exhibit a
region of voltage-controlled negative differential
resistance (NDR) above the threshold for impurity breakdown,
accompanied by a spontaneous current oscillation of
frequency fs ∼ 5 to 10 kHz. The dc I-V characteristics are
well explained in terms of a simple rate equation model and,
it is argued, the spontaneous current oscillations are due
to moving space charge waves which arise from a negative
differential rate of impurity impact ionization. ©
1986.},
Doi = {10.1016/0167-2789(86)90126-0},
Key = {Teitsworth86a}
}
@booklet{Westervelt86a,
Author = {Westervelt, RM and Teitsworth, SW},
Title = {Nonlinear dynamics and chaos in extrinsic
photoconductors},
Journal = {Physica D: Nonlinear Phenomena},
Volume = {23},
Number = {1-3},
Pages = {187-194},
Publisher = {Elsevier BV},
Year = {1986},
Month = {January},
ISSN = {0167-2789},
url = {http://dx.doi.org/10.1016/0167-2789(86)90127-2},
Abstract = {We present an experimental and theoretical analysis of the
nonlinear response of cooled extrinsic Ge photoconductors of
the type used to detect far-infrared radiation. State of the
art p-type Ge devices with nearly ideal noise performance in
the absence of drive show characteristic subharmonic and
chaotic nonlinear phenomena when periodically driven, with a
corresponding degredation in noise performance by a factor
≈ 104. A systematic series of experiments and
corresponding simulations of a standard model of extrinsic
photoconductors, including measurings and simulations of the
I-V curves, transient and small signal response, as well as
the response to periodic drive, identify the physical
transport processes responsible: the nonlinear electric
field dependence of the rates of free hole capture and
impact ionization due to carrier heating at relatively
modest applied electric fields E > 0.1 V/cm. ©
1986.},
Doi = {10.1016/0167-2789(86)90127-2},
Key = {Westervelt86a}
}
@booklet{Teitsworth83,
Author = {Teitsworth, SW and Westervelt, RM and Haller, EE},
Title = {Nonlinear oscillations and chaos in electrical breakdown in
Ge},
Journal = {Physical Review Letters},
Volume = {51},
Number = {9},
Pages = {825-828},
Publisher = {American Physical Society (APS)},
Year = {1983},
Month = {January},
ISSN = {0031-9007},
url = {http://dx.doi.org/10.1103/PhysRevLett.51.825},
Abstract = {Self-generated nonlinear oscillations and chaos are found in
the conductance of liquid-He-cooled far-infrared
photoconductors made from ultrapure Ge. Complex behavior
includes a period-doubling cascade to chaotic oscillation
with increasing applied electric field, quasiperiodic
oscillation, frequency locking, and intermittent switching
between modes of oscillation. A rate-equation model is
presented which includes impurity impact ionization and
space-charge injection. © 1983 The American Physical
Society.},
Doi = {10.1103/PhysRevLett.51.825},
Key = {Teitsworth83}
}
@booklet{Westervelt85,
Author = {Westervelt, RM and Teitsworth, SW},
Title = {Nonlinear transient response of extrinsic Ge far-infrared
photoconductors},
Journal = {Journal of Applied Physics},
Volume = {57},
Number = {12},
Pages = {5457-5469},
Publisher = {AIP Publishing},
Year = {1985},
Month = {December},
ISSN = {0021-8979},
url = {http://dx.doi.org/10.1063/1.334822},
Abstract = {Physical mechanisms responsible for nonlinear phenomena and
anomalous transient response of cooled extrinsic
far-infrared photoconductors are discussed. A simple model
describing carrier generation, trapping, and impact
ionization is presented, which describes the transient
response on fast time scales 10-3 to 10-4 sec, neglecting
changes in space charge. Carrier heating by a dc electric
field produces relatively fast, damped oscillatory response
to external excitation. A small-signal analysis of these
equations is a test of stability. An analysis of the role of
ideal electrical contacts and space charge is also
presented. The very slow (∼1 sec) overshoot and transient
response commonly observed in cooled extrinsic
photoconductors is explained by the dynamics of trapped
space charge near the injecting electrical contact. A
small-signal analysis determines the characteristic time
constants for these processes, which are typically ∼1 sec.
Calculated examples of the recombination and ionization
coefficients, dc I-V curves, differential equation flow
diagrams, and transient response are presented for
parameters typical of p-type Ge photoconductors doped with
shallow acceptor levels, and suggestions for the design of
more stable photoconductors are presented.},
Doi = {10.1063/1.334822},
Key = {Westervelt85}
}
@article{fds248436,
Author = {Bonilla, LL and Teitsworth, SW},
Title = {Nonlinear Wave Methods for Charge Transport},
Journal = {Nonlinear Wave Methods for Charge Transport},
Year = {2010},
Month = {September},
url = {http://dx.doi.org/10.1002/9783527628674},
Abstract = {The present book introduces and develops mathematical
techniques for the treatment of nonlinear waves and singular
perturbation methods at a level that is suitable for
graduate students, researchers and faculty throughout the
natural sciences and engineering. The practice of
implementing these techniques and their value are largely
realized by showing their application to problems of
nonlinear wave phenomena in electronic transport in solid
state materials, especially bulk semiconductors and
semiconductor superlattices. The authors are recognized
leaders in this field, with more than 30 combined years of
contributions. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA. All
rights reserved.},
Doi = {10.1002/9783527628674},
Key = {fds248436}
}
@article{fds248437,
Author = {Bonilla, LL and Teitsworth, SW},
Title = {Nonlinear Wave Methods for Charge Transport},
Journal = {Nonlinear Wave Methods for Charge Transport},
Year = {2010},
url = {http://dx.doi.org/10.1002/9783527628674},
Abstract = {The present book introduces and develops mathematical
techniques for the treatment of nonlinear waves and singular
perturbation methods at a level that is suitable for
graduate students, researchers and faculty throughout the
natural sciences and engineering. The practice of
implementing these techniques and their value are largely
realized by showing their application to problems of
nonlinear wave phenomena in electronic transport in solid
state materials, especially bulk semiconductors and
semiconductor superlattices. The authors are recognized
leaders in this field, with more than 30 combined years of
contributions. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.
All rights reserved.},
Doi = {10.1002/9783527628674},
Key = {fds248437}
}
@article{fds248450,
Author = {Xu, H and Teitsworth, SW},
Title = {On the possibility of a shunt-stabilized superlattice
terahertz emitter},
Journal = {Applied Physics Letters},
Volume = {96},
Number = {2},
Pages = {022101-022101},
Publisher = {AIP Publishing},
Year = {2010},
Month = {January},
ISSN = {0003-6951},
url = {http://hdl.handle.net/10161/3244 Duke open
access},
Abstract = {High field electronic transport through a strongly coupled
superlattice (SL) with a shunting side layer is numerically
studied using a drift-diffusion model that includes both
vertical and lateral dynamics. The bias voltage corresponds
to an average electric field in the negative differential
conductivity region of the intrinsic current-field curve of
the SL, a condition that generally implies space charge
instability. Key structural parameters associated with both
the shunt layer and SL are identified for which the shunt
layer stabilizes a uniform electric field profile. These
results support the possibility to realize a SL-based
terahertz oscillator with a carefully designed structure. ©
2010 American Institute of Physics.},
Doi = {10.1063/1.3291614},
Key = {fds248450}
}
@article{fds248454,
Author = {Xu, H and Teitsworth, SW},
Title = {On the possibility of a shunt-stabilized superlattice THz
emitter},
Journal = {Applied Physics Letters},
Volume = {96},
Number = {022101},
Pages = {3 pages},
Year = {2010},
Abstract = {High field electronic transport through a strongly-coupled
superlattice (SL) with a shunting side layer is numerically
studied using a novel drift-diffusion model. The bias
voltage corresponds to an average electric field in the
negative differential conductivity (NDC) region of the
intrinsic current-field (I ¡ F) curve of the SL, a
condition that generally implies space charge instability.
Key structural parameters associated with both the shunt
layer and SL are identified for which the shunt layer
stabilizes a uniform electric field profile. These results
support the possibility to realize a SL-based THz oscillator
with a carefully designed structure.},
Key = {fds248454}
}
@booklet{Bonilla94,
Author = {Bonilla, LL and Cantalapiedra, IR and Bergmann, MJ and Teitsworth,
SW},
Title = {Onset of current oscillations in extrinsic semiconductors
under DC voltage bias},
Journal = {Semiconductor Science and Technology},
Volume = {9},
Number = {5 S},
Pages = {599-602},
Publisher = {IOP Publishing},
Year = {1994},
Month = {December},
ISSN = {0268-1242},
url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:A1994NM75300054&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
Abstract = {We present a model which describes the onset of current
instabilities and space-charge domains in extrinsic
semiconductors (especially p-Ge) under DC voltage bias. Just
above the onset voltage for current instability we have
found numerically small-amplitude fast oscillations due to
the periodic motion of solitary waves which decay before
reaching the receiving contact. For slightly larger applied
voltages there is an abrupt and slightly hysteretic
transition to slower large-amplitude solitary waves similar
to those in the Gunn effect. An amplitude equation is
derived for long samples which reveals a quasicontinuum of
oscillatory modes that become linearly unstable at
onset.},
Doi = {10.1088/0268-1242/9/5S/054},
Key = {Bonilla94}
}
@booklet{Banoo96,
Author = {Banoo, K},
Title = {Phonon scattering in novel superlattice-asymmetric double
barrier resonant tunneling structure},
Journal = {Journal of Vacuum Science and Technology B: Microelectronics
and Nanometer Structures},
Volume = {14},
Number = {4},
Pages = {2725-2730},
Year = {1996},
Abstract = {The scattering effects (specifically LO-phonon scattering)
in a 45 Å AlAs/80 Å GaAs/33 A AlAs asymmetric double
barrier resonant tunneling (ADBRT) structure with a short
period GaAS/Al0.3Ga0.7As superlattice incorporated on one
side of the double barrier have been studied and
characterized. Enhanced levels of current conduction were
produced in the ADBRT due to the superlattice miniband
electron transport under forward bias. And the effect of the
said superlattice on the phonon scattering phenomena
exhibited by the entire device was subsequently examined.
Magnetic field fan diagrams at 4.2 K under reverse bias
showed a new feature at an energy of 22 meV that could be
explained on the basis of previously unreported GaAs
LO-phonon scattering processes from the first excited
emitter level. Finally, quenching of phonon-assisted
tunneling in reverse bias on decreasing the period of the
superlattice was also observed. © 1996 American Vacuum
Society.},
Key = {Banoo96}
}
@booklet{Turley91a,
Author = {Turley, PJ and Teitsworth, SW},
Title = {Phonon-assisted tunneling due to localized modes in
double-barrier structures.},
Journal = {Physical review. B, Condensed matter},
Volume = {44},
Number = {15},
Pages = {8181-8184},
Year = {1991},
Month = {October},
ISSN = {0163-1829},
url = {http://www.ncbi.nlm.nih.gov/pubmed/9998750},
Doi = {10.1103/physrevb.44.8181},
Key = {Turley91a}
}
@booklet{Turley94,
Author = {Turley, PJ and Teitsworth, SW},
Title = {Phonon-assisted tunneling from a two-dimensional emitter
state.},
Journal = {Physical review. B, Condensed matter},
Volume = {50},
Number = {12},
Pages = {8423-8432},
Year = {1994},
Month = {September},
ISSN = {0163-1829},
url = {http://www.ncbi.nlm.nih.gov/pubmed/9974860},
Doi = {10.1103/physrevb.50.8423},
Key = {Turley94}
}
@article{fds248488,
Author = {Olafsen, LJ and Daniels-Race, T and Kendall, RE and Teitsworth,
SW},
Title = {Photoluminescence of n-i-n GaAs/AlAs single quantum well
structures under electric field bias},
Journal = {Superlattices and Microstructures},
Volume = {27},
Number = {1},
Pages = {39-51},
Publisher = {Elsevier BV},
Year = {2000},
Month = {January},
ISSN = {0749-6036},
url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000085519800006&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
Abstract = {GaAs/AlAs single quantum well structures designed with well
thickness near the type-I/type-II crossover show distinctive
photoluminescence peaks corresponding to both type-I and
type-II recombinations. Photoluminescence measurements as a
function of applied electric field and temperature ranging
from 23 to 180 K and current-voltage measurements are
presented for two MBE-grown structures clad with Si-doped
Al0.45Ga0.55As layers on n+-GaAs [100] substrates. The large
and field-dependent energy separation between type-I and
type-II luminescence peaks is understood to arise from the
build-up of electrons at the X point in the AlAs
barrier.},
Doi = {10.1006/spmi.1999.0818},
Key = {fds248488}
}
@article{fds4224,
Author = {S.W. Teitsworth},
Title = {Quantum chaos effects in mechanical wave
systems},
Series = {Springer-Verlag},
Booktitle = {Proceedings of the 16th Sitges conference},
Editor = {D. Reguera et al.},
Year = {2000},
Key = {fds4224}
}
@article{fds304620,
Author = {Rogozia, M and Teitsworth, SW and Grahn, HT and Ploog,
KH},
Title = {Relocation dynamics of domain boundaries in semiconductor
superlattices},
Journal = {Physical Review B - Condensed Matter and Materials
Physics},
Volume = {65},
Number = {20},
Pages = {1-7},
Publisher = {American Physical Society (APS)},
Year = {2002},
Month = {January},
ISSN = {0163-1829},
url = {http://dx.doi.org/10.1103/PhysRevB.65.205303},
Abstract = {The formation of static electric-field domains in doped
semiconductor superlattices appears in the current-voltage
(formula presented) characteristics as multiple current
branches separated by abrupt discontinuities. The switching
dynamics of the charge-accumulation layer forming the domain
boundary is experimentally investigated at dc voltages in
the first plateau of the (formula presented) characteristic
for different polarities and amplitudes of the applied
voltage steps. When the voltage is decreased (down jumps)
from its initial dc value, the accumulation layer can
directly move from its initial position to its final
position, in accordance with the direction of the applied
voltage step. However, when the voltage is increased (up
jumps), there are two different modes of the relocation
motion of the accumulation layer. For small up jumps, the
accumulation layer can still move directly from its initial
to its final position. When the amplitude of the transient
current peak is above a critical value, a charge dipole is
injected at the emitter contact, in addition to the existing
monopole formed by the domain boundary. The experimentally
observed switching behavior is in excellent qualitative
agreement with recent theoretical work [A. Amann et al.,
Phys. Rev. E 63, 066207 (2001)]. © 2002 The American
Physical Society.},
Doi = {10.1103/PhysRevB.65.205303},
Key = {fds304620}
}
@article{fds248490,
Author = {Rogozia, M and Teitsworth, SW and Grahn, HT and Ploog,
KH},
Title = {Relocation dynamics of domain boundaries in semiconductor
superlattices},
Journal = {Physical Review B},
Volume = {65},
Number = {205303},
Pages = {1-7},
Year = {2002},
ISSN = {0163-1829},
Abstract = {The formation of static electric-field domains in doped
semiconductor superlattices appears in the current-voltage
(I-V) characteristics as multiple current branches separated
by abrupt discontinuities. The switching dynamics of the
charge-accumulation layer forming the domain boundary is
experimentally investigated at dc voltages in the first
plateau of the I-V characteristic for different polarities
and amplitudes of the applied voltage steps. When the
voltage is decreased (down jumps) from its initial dc value,
the accumulation layer can directly move from its initial
position to its final position, in accordance with the
direction of the applied voltage step. However, when the
voltage is increased (up jumps), there are two different
modes of the relocation motion of the accumulation layer.
For small up jumps, the accumulation layer can still move
directly from its initial to its final position. When the
amplitude of the transient current peak is above a critical
value, a charge dipole is injected at the emitter contact,
in addition to the existing monopole formed by the domain
boundary. The experimentally observed switching behavior is
in excellent qualitative agreement with recent theoretical
work [A. Amann et al., Phys. Rev. E 63, 066207
(2001)].},
Key = {fds248490}
}
@article{fds342478,
Author = {Teitsworth, SW and Olson, ME and Bomze, Y},
Title = {Scaling properties of noise-induced switching in a bistable
tunnel diode circuit},
Journal = {European Physical Journal B},
Volume = {92},
Number = {4},
Year = {2019},
Month = {April},
url = {http://dx.doi.org/10.1140/epjb/e2019-90711-0},
Abstract = {Abstract: Noise-induced switching between coexisting
metastable states occurs in a wide range of
far-from-equilibrium systems including micro-mechanical
oscillators, epidemiological and climate change models, and
nonlinear electronic transport in tunneling structures such
as semiconductor superlattices and tunnel diodes. In the
case of tunnel diode circuits, noise-induced switching
behavior is associated with negative differential resistance
in the static current–voltage characteristics and
bistability, i.e., the existence of two macroscopic current
states for a given applied voltage. Noise effects are
particularly strong near the onset and offset of bistable
current behavior, corresponding to bifurcation points in the
associated dynamical system. In this paper, we show that the
tunnel diode system provides an excellent experimental
platform for the precision measurement of scaling properties
of mean switching times versus applied voltage near
bifurcation points. More specifically, experimental data
confirm that the mean switching time scales logarithmically
as the 3/2 power of voltage difference over an exceptionally
wide range of time scales and noise intensities. Graphical
abstract: [Figure not available: see fulltext.].},
Doi = {10.1140/epjb/e2019-90711-0},
Key = {fds342478}
}
@booklet{Turley95,
Author = {Turley, PJ and Wallis, CR and Teitsworth, SW},
Title = {Selection rule for localized phonon emission in GaAs/AlAs
double-barrier structures},
Journal = {Journal of Applied Physics},
Volume = {78},
Number = {10},
Pages = {6104-6107},
Publisher = {AIP Publishing},
Year = {1995},
Month = {January},
ISSN = {0021-8979},
url = {http://dx.doi.org/10.1063/1.360551},
Abstract = {Phonon-assisted tunneling (PAT) has been studied in detail
for two similar GaAs/AlAs double-barrier structures.
Calculations of the PAT current - including effects of
optical-phonon localization - are in good agreement with
experimental data, and the emission rate for certain phonon
types is found to depend sensitively on GaAs well width. We
find that GaAs-like modes clearly dominate in structures
with wider wells, while GaAs and AlAs-like modes contribute
equivalently in narrower well structures. A simple overlap
integral - involving the phonon potential and electronic
wave functions - provides an effective selection rule for
determining which types of phonons are preferentially
emitted. © 1995 American Institute of Physics.},
Doi = {10.1063/1.360551},
Key = {Turley95}
}
@booklet{Bergmann96,
Author = {Bergmann, MJ and Teitsworth, SW and Bonilla, LL and Cantalapiedra,
IR},
Title = {Solitary-wave conduction in p-type Ge under time-dependent
voltage bias.},
Journal = {Physical review. B, Condensed matter},
Volume = {53},
Number = {3},
Pages = {1327-1335},
Year = {1996},
Month = {January},
ISSN = {0163-1829},
url = {http://www.ncbi.nlm.nih.gov/pubmed/9983592},
Doi = {10.1103/physrevb.53.1327},
Key = {Bergmann96}
}
@booklet{Cantalapiedra93,
Author = {Cantalapiedra, IR and Bonilla, LL and Bergmann, MJ and Teitsworth,
SW},
Title = {Solitary-wave dynamics in extrinsic semiconductors under dc
voltage bias.},
Journal = {Physical review. B, Condensed matter},
Volume = {48},
Number = {16},
Pages = {12278-12281},
Year = {1993},
Month = {October},
ISSN = {0163-1829},
url = {http://www.ncbi.nlm.nih.gov/pubmed/10007580},
Doi = {10.1103/physrevb.48.12278},
Key = {Cantalapiedra93}
}
@article{fds248487,
Author = {Rogozia, M and Teitsworth, SW and Grahn, HT and Ploog,
K},
Title = {Statistics of the domain boundary relocation time in
semiconductor superlattices},
Journal = {Physical Review B - Rapid Communications},
Volume = {64},
Number = {041308},
Pages = {1-4},
Year = {2001},
ISSN = {0163-1829},
Abstract = {Static domain formation in doped semiconductor superlattices
results in several current branches separated by abrupt
discontinuities that exhibit hysteresis. The transition from
one branch to its adjacent one is studied by time-resolved
switching experiments. The mean value of the relocation time
increases by more than one order of magnitude, when the
final voltage on the adjacent branch is reduced to a value
approaching the discontinuity. At the same time, the
distribution function of the relocation time changes from a
simple Gaussian to a first-passage time form.},
Key = {fds248487}
}
@article{fds304619,
Author = {Teitsworth, SW and Rogozia, M and Grahn, HT and Ploog,
KH},
Title = {Statistics of the domain-boundary relocation time in
semiconductor superlattices},
Journal = {Physical Review B - Condensed Matter and Materials
Physics},
Volume = {64},
Number = {4},
Pages = {413081-413084},
Publisher = {American Physical Society (APS)},
Year = {2001},
Month = {January},
ISSN = {0163-1829},
url = {http://dx.doi.org/10.1103/PhysRevB.64.041308},
Abstract = {Static domain formation in doped semiconductor superlattices
results in several current branches separated by abrupt
discontinuities that exhibit hysteresis. The transition from
one branch to its adjacent one is studied by time-resolved
switching experiments. The mean value of the relocation time
increases by more than one order of magnitude, when the
final voltage on the adjacent branch is reduced to a value
approaching the discontinuity. At the same time, the
distribution function of the relocation time changes from a
simple Gaussian to a first-passage time form. © 2001 The
American Physical Society.},
Doi = {10.1103/PhysRevB.64.041308},
Key = {fds304619}
}
@article{fds248435,
Author = {Dannenberg, PH and Neu, JC and Teitsworth, SW},
Title = {Steering most probable escape paths by varying relative
noise intensities.},
Journal = {Physical review letters},
Volume = {113},
Number = {2},
Pages = {020601},
Publisher = {American Physical Society},
Year = {2014},
Month = {July},
ISSN = {0031-9007},
url = {http://dx.doi.org/10.1103/physrevlett.113.020601},
Abstract = {We demonstrate the possibility to systematically steer the
most probable escape paths (MPEPs) by adjusting relative
noise intensities in dynamical systems that exhibit
noise-induced escape from a metastable point via a saddle
point. With the use of a geometric minimum action approach,
an asymptotic theory is developed that is broadly applicable
to fast-slow systems and shows the important role played by
the nullcline associated with the fast variable in locating
the MPEPs. A two-dimensional quadratic system is presented
which permits analytical determination of both the MPEPs and
associated action values. Analytical predictions agree with
computed MPEPs, and both are numerically confirmed by
constructing prehistory distributions directly from the
underlying stochastic differential equation.},
Doi = {10.1103/physrevlett.113.020601},
Key = {fds248435}
}
@article{fds368731,
Author = {Teitsworth, S and Neu, JC},
Title = {Stochastic line integrals and stream functions as metrics of
irreversibility and heat transfer.},
Journal = {Physical review. E},
Volume = {106},
Number = {2-1},
Pages = {024124},
Publisher = {American Physical Society (APS)},
Year = {2022},
Month = {August},
url = {http://dx.doi.org/10.1103/physreve.106.024124},
Abstract = {Stochastic line integrals are presented as a useful metric
for quantitatively characterizing irreversibility and
detailed balance violation in noise-driven dynamical
systems. A particular realization is the stochastic area,
recently studied in coupled electrical circuits. Here we
provide a general framework for understanding properties of
stochastic line integrals and clarify their implementation
for experiments and simulations. For two-dimensional
systems, stochastic line integrals can be expressed in terms
of a stream function, the sign of which determines the
orientation of nonequilibrium steady-state probability
currents. Theoretical results are supported by numerical
studies of an overdamped two-dimensional mass-spring system
driven out of equilibrium. Additionally, the stream function
permits analytical understanding of the scaling dependence
of stochastic area growth rate on key parameters such as the
noise strength for both linear and nonlinear
springs.},
Doi = {10.1103/physreve.106.024124},
Key = {fds368731}
}
@booklet{Teitsworth86b,
Author = {Teitsworth, SW and Westervelt, RM},
Title = {Subharmonic and chaotic response of periodically driven
extrinsic Ge photoconductors.},
Journal = {Physical review letters},
Volume = {56},
Number = {5},
Pages = {516-519},
Year = {1986},
Month = {February},
url = {http://www.ncbi.nlm.nih.gov/pubmed/10033212},
Doi = {10.1103/physrevlett.56.516},
Key = {Teitsworth86b}
}
@article{fds248455,
Author = {Heinrich, M and Dahms, T and Flunkert, V and Teitsworth, SW and Schöll,
E},
Title = {Symmetry-breaking transitions in networks of nonlinear
circuit elements},
Journal = {New Journal of Physics},
Volume = {12},
Number = {11},
Pages = {113030-113030},
Publisher = {IOP Publishing},
Year = {2010},
Month = {November},
ISSN = {1367-2630},
url = {http://dx.doi.org/10.1088/1367-2630/12/11/113030},
Abstract = {We investigate a nonlinear circuit consisting of N tunnel
diodes in series, which shows close similarities to a
semiconductor superlattice or to a neural network. Each
tunnel diode is modeled by a three-variable
FitzHugh-Nagumo-like system. The tunnel diodes are coupled
globally through a load resistor. We find complex
bifurcation scenarios with symmetry-breaking transitions
that generate multiple fixed points off the synchronization
manifold. We show that multiply degenerate zero-eigenvalue
bifurcations occur, which lead to multistable current
branches, and that these bifurcations are also degenerate
with a Hopf bifurcation. These predicted scenarios of
multiple branches and degenerate bifurcations are also found
experimentally. © IOP Publishing Ltd and Deutsche
Physikalische Gesellschaft.},
Doi = {10.1088/1367-2630/12/11/113030},
Key = {fds248455}
}
@article{fds335615,
Author = {Neu, JC and Ghanta, A and Teitsworth, SW},
Title = {The Geometry of most probable trajectories in noise-driven
dynamical systems},
Journal = {Springer Proceedings in Mathematics and Statistics},
Volume = {232},
Series = {Springer Proceedings in Mathematics and Statistics},
Pages = {153-167},
Booktitle = {Coupled Mathematical Models for Physical and Biological
Nanoscale Systems and Their Applications},
Publisher = {Springer International Publishing},
Address = {Gewerbestr. 11, 6330 Cham, Switzerland},
Editor = {L. L. Bonilla and E. Kaxiras and R. Melnik},
Year = {2018},
Month = {January},
ISBN = {9783319765983},
url = {https://arxiv.org/abs/1803.01053},
Keywords = {transition path, geometric stochastic action, •
fluctuation loops},
Abstract = {This paper presents a heuristic derivation of a geometric
minimum action method that can be used to determine
most-probable transition paths in noise-driven dynamical
systems. Particular attention is focused on systems that
violate detailed balance, and the role of the stochastic
vorticity tensor is emphasized. The general method is
explored through a detailed study of a two-dimensional
quadratic shear flow which exhibits bifurcating
most-probable transition pathways.},
Doi = {10.1007/978-3-319-76599-0_9},
Key = {fds335615}
}
@booklet{Teitsworth89,
Author = {Teitsworth, SW},
Title = {The physics of space charge instabilities and temporal chaos
in extrinsic photoconductors},
Journal = {Applied Physics A Solids and Surfaces},
Volume = {48},
Number = {2},
Pages = {127-136},
Publisher = {Springer Nature},
Year = {1989},
Month = {February},
url = {http://dx.doi.org/10.1007/BF01141274},
Abstract = {This paper reviews experimental and theoretical work carried
out on space charge instabilities and temporal chaotic
behavior in cooled extrinsic p-type Germanium
photoconductors. Measured dc current-voltage (I-V)
characteristics of these devices are strongly nonlinear for
moderate electric fields ≧0.1 V/cm due to field dependence
of the rates of free hole capture and impurity impact
ionization. Below the threshold field for impurity
breakdown, Ge samples behave like damped nonlinear
oscillators, exhibiting characteristic chaotic response when
driven by a time-periodic voltage. Above impurity breakdown,
we observe voltage-controlled negative differential
resistance (NDR) in the I-V curves accompanied by
spontaneous current oscillations due to moving space charge
domains with velocities 103 to 104 cm/s. Measurements are
well explained by a simple rate equation model in which
negative differential behavior in the impact ionization rate
plays a crucial role. Related work on semiconductor chaos
and possible future directions for research are also
mentioned. © 1989 Springer-Verlag.},
Doi = {10.1007/BF01141274},
Key = {Teitsworth89}
}
@booklet{Turley92,
Author = {Turley, PJ and Teitsworth, SW},
Title = {Theory of localized phonon modes and their effects on
electron tunneling in double-barrier structures},
Journal = {Journal of Applied Physics},
Volume = {72},
Number = {6},
Pages = {2356-2366},
Publisher = {AIP Publishing},
Year = {1992},
Month = {December},
ISSN = {0021-8979},
url = {http://dx.doi.org/10.1063/1.351577},
Abstract = {The role of localized phonon modes in phonon-assisted
tunneling in GaAs/AlAs double-barrier resonant tunneling
structures is considered for a range of temperatures and
magnetic fields. Phonon modes are calculated using a
dielectric continuum model and electron-phonon Hamiltonians
are presented for the most important modes. Formulas for
phonon-assisted tunneling currents are derived that express
the inherently three-dimensional process in a simple
one-dimensional form. It is found that the excess current
due to phonon-assisted tunneling in typical structures is
caused primarily by two types of localized modes: confined
modes in the well and symmetric interface modes, with
interface modes dominating in structures with narrow wells.
Current peaks broaden with increasing temperature, and for
temperatures ≳20 K the resolution of features due to
distinct phonon types is very difficult. The application of
a magnetic field parallel to the current flow leads to a
complex spectrum of sharp current peaks corresponding to
various inter-Landau-level transitions which occur during
phonon-assisted tunneling.},
Doi = {10.1063/1.351577},
Key = {Turley92}
}
@booklet{Bonilla91,
Author = {Bonilla, LL and Teitsworth, SW},
Title = {Theory of periodic and solitary space charge waves in
extrinsic semiconductors},
Journal = {Physica D: Nonlinear Phenomena},
Volume = {50},
Number = {3},
Pages = {545-559},
Publisher = {Elsevier BV},
Year = {1991},
Month = {January},
ISSN = {0167-2789},
url = {http://dx.doi.org/10.1016/0167-2789(91)90014-Z},
Abstract = {We present a theory of the existence and stability of
traveling periodic and solitary space charge wave solutions
to a standard rate equation model of electrical conduction
in extrinsic semiconductors which includes effects of
field-dependent impurity impact ionization. A nondimensional
set of equations is presented in which the small parameter
β = (dielectric relaxation time) / (characteristic impurity
time) ≫ 1 plays a crucial role for our singular
perturbation analysis. For a narrow range of wave velocities
a phase plane analysis gives a set of limit cycle orbits
corresponding to periodic traveling waves. while for a
unique value of wave velocity we find a homoclinic orbit
corresponding to a moving solitary space charge wave of the
type experimentally observed in p-type germanium. A linear
stability analysis reveals all waves to be unstable under
current bias on the infinite one-dimensional line. Finally,
we conjecture that solitary waves may be stable in samples
of finite length under voltage bias. © 1991.},
Doi = {10.1016/0167-2789(91)90014-Z},
Key = {Bonilla91}
}
@article{fds248491,
Author = {Rogozia, M and Grahn, HT and Teitsworth, SW and Ploog,
KH},
Title = {Time distribution of the domain-boundary relocation in
superlattices},
Journal = {Physica B: Condensed Matter},
Volume = {314},
Number = {1-4},
Pages = {427-430},
Publisher = {Elsevier BV},
Year = {2002},
Month = {March},
ISSN = {0921-4526},
url = {http://dx.doi.org/10.1016/S0921-4526(01)01387-4},
Abstract = {Static domain formation in doped, weakly coupled
semiconductor superlattices results in several current
branches separated by discontinuities that exhibit
hysteresis. The transition from one branch to its adjacent
higher and lower one is studied by time-resolved switching
experiments. The distribution function of the relocation
time for up and down jumps changes from a simple Gaussian to
a first-passage time (FPT) form, when the final voltage on
the adjacent branch approaches a discontinuity in the
current-voltage characteristic. This observation indicates
that for a smaller voltage distance from the discontinuity
(FPT distribution) the system reaches the final state via an
unstable intermediate state. In contrast, for a larger
voltage distance from the discontinuity (Gaussian
distribution), the system arrives directly at the final
state, because the intermediate state does not exist. ©
2002 Elsevier Science B.V. All rights reserved.},
Doi = {10.1016/S0921-4526(01)01387-4},
Key = {fds248491}
}
@booklet{Turley93,
Author = {Turley, PJ and Wallis, CR and Teitsworth, SW and Li, W and Bhattacharya,
PK},
Title = {Tunneling measurements of symmetrical-interface phonons in
gaas/alas double-barrier structures},
Journal = {Physical Review B},
Volume = {47},
Number = {19},
Pages = {12640-12648},
Year = {1993},
Month = {May},
ISSN = {0163-1829},
url = {http://www.ncbi.nlm.nih.gov/pubmed/10005459},
Doi = {10.1103/physrevb.47.12640},
Key = {Turley93}
}
%% Preprints
@article{fds199873,
Author = {M. Heymann and S. W. Teitsworth and J. Mattingly},
Title = {Rare transition events in non-equilibrium systems with
state-dependent noise: application to stochastic current
switching in semiconductor superlattices},
Year = {2012},
Abstract = {Using recent mathematical advances, a geometric approach to
rare noise-driven transition events in nonequilibrium
systems is given, and an algorithm for computing the maximum
likelihood transition curve is generalized to the case of
state-dependent noise. It is applied to a model of
electronic transport in semiconductor superlattices to
investigate transitions between metastable electric field
distributions. When the applied voltage V is varied near a
saddle-node bifurcation at Vth , the mean life time T of the
initial metastable state is shown to scale like log T
\propto |Vth − V |^{3/2}.},
Key = {fds199873}
}