%% Papers Published
@article{fds248493,
Author = {Joseph, JA and Thomas, JE and Kulkarni, M and Abanov,
AG},
Title = {Observation of shock waves in a strongly interacting Fermi
gas.},
Journal = {Physical review letters},
Volume = {106},
Number = {15},
Pages = {150401},
Year = {2011},
Month = {April},
url = {http://www.ncbi.nlm.nih.gov/pubmed/21568532},
Abstract = {We study collisions between two strongly interacting atomic
Fermi gas clouds. We observe exotic nonlinear hydrodynamic
behavior, distinguished by the formation of a very sharp and
stable density peak as the clouds collide and subsequent
evolution into a boxlike shape. We model the nonlinear
dynamics of these collisions by using quasi-1D hydrodynamic
equations. Our simulations of the time-dependent density
profiles agree very well with the data and provide clear
evidence of shock wave formation in this universal quantum
hydrodynamic system.},
Doi = {10.1103/physrevlett.106.150401},
Key = {fds248493}
}
@article{fds248492,
Author = {Cao, C and Elliott, E and Joseph, J and Wu, H and Petricka, J and Schäfer,
T and Thomas, JE},
Title = {Universal quantum viscosity in a unitary Fermi
gas.},
Journal = {Science (New York, N.Y.)},
Volume = {331},
Number = {6013},
Pages = {58-61},
Year = {2011},
Month = {January},
url = {http://www.ncbi.nlm.nih.gov/pubmed/21148347},
Abstract = {A Fermi gas of atoms with resonant interactions is predicted
to obey universal hydrodynamics, in which the shear
viscosity and other transport coefficients are universal
functions of the density and temperature. At low
temperatures, the viscosity has a universal quantum scale ħ
n, where n is the density and ħ is Planck's constant h
divided by 2π, whereas at high temperatures the natural
scale is p(T)(3)/ħ(2), where p(T) is the thermal momentum.
We used breathing mode damping to measure the shear
viscosity at low temperature. At high temperature T, we used
anisotropic expansion of the cloud to find the viscosity,
which exhibits precise T(3/2) scaling. In both experiments,
universal hydrodynamic equations including friction and
heating were used to extract the viscosity. We estimate the
ratio of the shear viscosity to the entropy density and
compare it with that of a perfect fluid.},
Doi = {10.1126/science.1195219},
Key = {fds248492}
}
@article{fds183756,
Author = {J.E. Thomas},
Title = {The nearly perfect Fermi gas},
Journal = {Physics Today},
Series = {May 2010},
Pages = {34-37},
Year = {2010},
Month = {May},
Key = {fds183756}
}
@article{fds248495,
Author = {Thomas, JE},
Title = {Is an ultra-cold strongly interacting Fermi gas a perfect
fluid},
Journal = {Nucl. Phys. A},
Volume = {830},
Pages = {635},
Year = {2009},
Month = {October},
Key = {fds248495}
}
@article{fds248496,
Author = {Du, X and Zhang, Y and Petricka, J and Thomas, JE},
Title = {Controlling spin current in a trapped Fermi
gas.},
Journal = {Physical review letters},
Volume = {103},
Number = {1},
Pages = {010401},
Year = {2009},
Month = {July},
ISSN = {0031-9007},
url = {http://www.ncbi.nlm.nih.gov/pubmed/19659125},
Abstract = {We study fundamental features of spin current in a very
weakly interacting Fermi gas of 6Li. By creating a spin
current and then reversing its flow, we demonstrate control
of the spin current. This reversal is predicted by a spin
vector evolution equation in energy representation, which
shows how the spin and energy of individual atoms become
correlated in the nearly undamped regime of the experiments.
The theory provides a simple physical description of the
spin current and explains both the large amplitude and the
slow temporal evolution of the data. Our results have
applications in studying and controlling fundamental spin
interactions and spin currents in ultracold
gases.},
Doi = {10.1103/physrevlett.103.010401},
Key = {fds248496}
}
@article{fds248497,
Author = {Du, X and Zhang, Y and Thomas, JE},
Title = {Inelastic collisions of a Fermi gas in the BEC-BCS
crossover.},
Journal = {Physical review letters},
Volume = {102},
Number = {25},
Pages = {250402},
Year = {2009},
Month = {June},
ISSN = {0031-9007},
url = {http://www.ncbi.nlm.nih.gov/pubmed/19659058},
Abstract = {We measure inelastic three-body and two-body collisional
decay rates for a two-component Fermi gas of 6Li, which are
highly suppressed by the Pauli exclusion principle. Our
measurements are made in the BEC-BCS crossover regime, near
the two-body collisional (Feshbach) resonance. At high
temperature (energy) the data show a dominant three-body
decay process, which is studied as a function of bias
magnetic field. At low energy, the data show a coexistence
of two-body and three-body decay processes near and below
the Feshbach resonance. Below resonance, the observed
two-body inelastic decay can arise from molecule-atom and
molecule-molecule collisions. We suggest that at and above
resonance, an effective two-body decay rate arises from
collisions between atoms and correlated (Cooper) pairs that
can exist at sufficiently low temperature.},
Doi = {10.1103/physrevlett.102.250402},
Key = {fds248497}
}
@article{fds248494,
Author = {Luo, L and Thomas, JE},
Title = {Thermodynamic measurements in strongly interacting Fermi
gas},
Journal = {Journal of Low Temperature Physics},
Volume = {154},
Number = {1-2},
Pages = {1-29},
Publisher = {Springer Nature},
Year = {2009},
Month = {January},
ISSN = {0022-2291},
url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000261606000001&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
Abstract = {Strongly interacting Fermi gases provide a clean and
controllable laboratory system for modeling strong
interparticle interactions between fermions in nature, from
high temperature superconductors to neutron matter and
quark-gluon plasmas. Model-independent thermodynamic
measurements, which do not require theoretical models for
calibrations, are very important for exploring this
important system experimentally, as they enable direct tests
of predictions based on the best current non-perturbative
many-body theories. At Duke University, we use all-optical
methods to produce a strongly interacting Fermi gas of
spin-1/2-up and spin-1/2-down 6Li atoms that is magnetically
tuned near a collisional (Feshbach) resonance. We conduct a
series of measurements on the thermodynamic properties of
this unique quantum gas, including the energy E, entropy S,
and sound velocity c. Our model-independent measurements of
E and S enable a precision study of the finite temperature
thermodynamics. The E (S ) data are directly compared to
several recent predictions. The temperature in both the
superfluid and normal fluid regime is obtained from the
fundamental thermodynamic relation T = ∂E/∂S by
parameterizing the E(S) data using two different power laws
that are joined with continuous E and T at a certain entropy
S c, where the fit is optimized. We observe a significant
change in the scaling of E with S above and below S c.
Taking the fitted value of S c as an estimate of the
critical entropy for a superfluid-normal fluid phase
transition in the strongly interacting Fermi gas, we
estimate the critical parameters. Our E (S) data are also
used to experimentally calibrate the endpoint temperatures
obtained for adiabatic sweeps of the magnetic field between
the ideal and strongly interacting regimes. This enables the
first experimental calibration of the temperature scale used
in experiments on fermionic pair condensation, where the
ideal Fermi gas temperature is measured before sweeping the
magnetic field to the strongly interacting regime. Our
calibration shows that the ideal gas temperature measured
for the onset of pair condensation corresponds closely to
the critical temperature T c estimated in the strongly
interacting regime from the fits to our E(S) data. We also
calibrate the empirical temperature employed in studies of
the heat capacity and obtain nearly the same T c. We
determine the ground state energy by three different
methods, using sound velocity measurements, by extrapolating
E (S) to S = 0 and by measuring the ratio of the cloud sizes
in the strongly and weakly interacting regimes. The results
are in very good agreement with recent predictions. Finally,
using universal thermodynamic relations, we estimate the
chemical potential and heat capacity of the trapped gas from
the E(S) data. © Springer Science+Business Media, LLC
2008.},
Doi = {10.1007/s10909-008-9850-2},
Key = {fds248494}
}
@article{fds248499,
Author = {Du, X and Luo, L and Clancy, B and Thomas, JE},
Title = {Observation of anomalous spin segregation in a trapped Fermi
gas.},
Journal = {Physical review letters},
Volume = {101},
Number = {15},
Pages = {150401},
Year = {2008},
Month = {October},
ISSN = {0031-9007},
url = {http://www.ncbi.nlm.nih.gov/pubmed/18999574},
Abstract = {We report the observation of spin segregation, i.e.,
time-dependent separation of the spin density profiles of
two spin states, in a trapped, coherently prepared Fermi gas
of 6Li with a magnetically tunable scattering length a12
close to zero. For |a12| approximately = 5 bohr, as the
cloud profiles evolve, the measured difference in the
densities at the cloud center increases in 200 ms from 0 to
approximately = 60% of the initial mean density and changes
sign with a12. The data are in disagreement in both
amplitude and temporal evolution with a spin-wave theory for
a Fermi gas. In contrast, for a Bose gas, an analogous
theory has successfully described previous observations of
spin segregation. The observed segregated atomic density
profiles are far from equilibrium, yet they persist for
approximately = 5 s, long compared to the axial trapping
period of 6.9 ms. We find the zero crossing in a12=0, where
spin segregation ceases, at 527.5+/-0.2 G.},
Doi = {10.1103/physrevlett.101.150401},
Key = {fds248499}
}
@article{fds248498,
Author = {Thomas, JE},
Title = {Energy measurement and virial theorem for confined universal
Fermi gases},
Journal = {Physical Review A - Atomic, Molecular, and Optical
Physics},
Volume = {78},
Number = {1},
Pages = {013630},
Publisher = {American Physical Society (APS)},
Year = {2008},
Month = {July},
ISSN = {1050-2947},
url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000258180300186&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
Abstract = {Optically trapped two-component Fermi gases near a broad
Feshbach resonance exhibit universal thermodynamics, where
the properties of the gas are independent of the details of
the two-body scattering interactions. We show that the
measured cloud profiles of both species determine the total
energy of universal gases for any trapping potential U and
any spin mixture, without assuming either the local density
approximation or harmonic confinement. A global proof of the
virial theorem yields the total energy of the gas at all
temperatures in the scale-invariant form E= ?U/ , where ? is
an arbitrary energy scale in terms of which all length and
energy scales that appear in the confining potential are
written. This result enables model-independent energy
measurement in any trap by observing only the cloud
profiles, and provides a consistency check for many-body
calculations in the universal regime. © 2008 The American
Physical Society.},
Doi = {10.1103/PhysRevA.78.013630},
Key = {fds248498}
}
@article{fds248500,
Author = {Turlapov, A and Kinast, J and Clancy, B and Luo, L and Joseph, J and Thomas, JE},
Title = {Is a gas of strongly interacting atomic fermions a nearly
perfect fluid?},
Journal = {Journal of Low Temperature Physics},
Volume = {150},
Number = {3-4},
Pages = {567-576},
Publisher = {Springer Nature},
Year = {2008},
Month = {February},
ISSN = {0022-2291},
url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000252469100066&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
Abstract = {We use all-optical methods to produce a highly-degenerate
Fermi gas of spin-1/2 6Li atoms. A magnetic field tunes the
gas near a collisional (Feshbach) resonance, producing
strong interactions between spin-up and spin-down atoms. We
have measured properties of a breathing mode over a wide
range of temperatures. As the temperature is increased from
below the superfluid transition to above, the frequency of
the mode is always close to the hydrodynamic value, while
the damping rate increases. A complete explanation of both
the frequency and the damping rate in the normal collisional
regime has not been achieved. Our measurements of the
damping rate as a function of the energy of the gas are used
to estimate an upper bound on the viscosity. Using our new
measurements of the entropy of the gas, we estimate the
ratio of the shear viscosity to the entropy density and
compare the result with a recent string theory conjecture
for the minimum viscosity of a perfect quantum fluid. ©
Springer Science+Business Media, LLC 2007.},
Doi = {10.1007/s10909-007-9589-1},
Key = {fds248500}
}
@article{fds248502,
Author = {Clancy, B and Luo, L and Thomas, JE},
Title = {Observation of nearly perfect irrotational flow in normal
and superfluid strongly interacting Fermi
gases.},
Journal = {Physical review letters},
Volume = {99},
Number = {14},
Pages = {140401},
Year = {2007},
Month = {October},
ISSN = {0031-9007},
url = {http://www.ncbi.nlm.nih.gov/pubmed/17930648},
Abstract = {We study the hydrodynamic expansion of a rotating strongly
interacting Fermi gas by releasing a cigar-shaped cloud with
a known angular momentum from an optical trap. As the aspect
ratio of the expanding cloud approaches unity, the angular
velocity increases, indicating quenching of the moment of
inertia I to as low as 0.05 of the rigid body value I(rig).
Remarkably, we observe this behavior in both the superfluid
and collisional normal fluid regimes, which obey nearly
identical zero-viscosity irrotational hydrodynamics. We
attribute irrotational flow in the normal fluid to a decay
of the rotational part of the stream velocity during
expansion, which occurs when the shear viscosity is
negligible. Using conservation of angular momentum, we
directly observe a fundamental result of irrotational
hydrodynamics, I/I(rig) = delta2, where delta is the
deformation parameter of the cloud.},
Doi = {10.1103/physrevlett.99.140401},
Key = {fds248502}
}
@article{fds248503,
Author = {Joseph, J and Clancy, B and Luo, L and Kinast, J and Turlapov, A and Thomas, JE},
Title = {Measurement of sound velocity in a fermi gas near a feshbach
resonance},
Journal = {Physical Review Letters},
Volume = {98},
Number = {17},
Pages = {170401},
Publisher = {American Physical Society (APS)},
Year = {2007},
Month = {April},
ISSN = {0031-9007},
url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000246803900001&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
Abstract = {Sound waves are excited in an optically trapped degenerate
Fermi gas of spin-up and spin-down atoms with magnetically
tunable interactions. Measurements are made throughout the
crossover region, from a weakly interacting Fermi gas
through the resonant Fermi superfluid regime to a Bose
condensate of dimer molecules. The measured sound velocities
test theories of hydrodynamic wave propagation and
predictions of the equation of state. At resonance, the
sound velocity exhibits universal scaling with the Fermi
velocity, to within 1.8% over a factor of 30 in density. ©
2007 The American Physical Society.},
Doi = {10.1103/PhysRevLett.98.170401},
Key = {fds248503}
}
@article{fds248504,
Author = {Luo, L and Clancy, B and Joseph, J and Kinast, J and Thomas,
JE},
Title = {Measurement of the entropy and critical temperature of a
strongly interacting Fermi gas.},
Journal = {Physical review letters},
Volume = {98},
Number = {8},
Pages = {080402},
Year = {2007},
Month = {February},
ISSN = {0031-9007},
url = {http://www.ncbi.nlm.nih.gov/pubmed/17359072},
Abstract = {We report a model-independent measurement of the entropy,
energy, and critical temperature of a degenerate, strongly
interacting Fermi gas of atoms. The total energy is
determined from the mean square cloud size in the strongly
interacting regime, where the gas exhibits universal
behavior. The entropy is measured by sweeping a bias
magnetic field to adiabatically tune the gas from the
strongly interacting regime to a weakly interacting regime,
where the entropy is known from the cloud size after the
sweep. The dependence of the entropy on the total energy
quantitatively tests predictions of the finite-temperature
thermodynamics.},
Doi = {10.1103/physrevlett.98.080402},
Key = {fds248504}
}
@article{fds248506,
Author = {Luo, L and Clancy, B and Joseph, J and Kinast, J and Turlapov, A and Thomas, JE},
Title = {Evaporative cooling of unitary Fermi gas mixtures in optical
traps},
Journal = {New Journal of Physics},
Volume = {8},
Number = {9},
Pages = {213-213},
Publisher = {IOP Publishing},
Year = {2006},
Month = {September},
ISSN = {1367-2630},
url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000240807500003&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
Abstract = {We measure the scaling laws for the number of atoms and the
cloud size as a function of trap depth for evaporative
cooling of a unitary Fermi gas in an optical trap. A unitary
Fermi gas comprises a trapped mixture of atoms in two
hyperfine states which is tuned to a collisional (Feshbach)
resonance using a bias magnetic field. Near resonance, the
zero energy s-wave scattering length diverges, and the
s-wave scattering cross-section is limited by unitarity to
be 4π/k2, where k is the relative wavevector of the
colliding particles. In this case, the collision
cross-section for evaporation scales inversely with the trap
depth, enabling runaway evaporation under certain
conditions. We demonstrate high evaporation efficiency,
which is achieved by maintaining a high ratio ηof trap
depth to thermal energy as the trap depth is lowered. We
derive and demonstrate a trap lowering curve which maintains
η constant for a unitary gas. This evaporation curve yields
a quantum degenerate sample from a classical gas in a
fraction of a second, with only a factor of three loss in
atom number. © IOP Publishing Ltd and Deutsche
Physikalische Gesellschaft.},
Doi = {10.1088/1367-2630/8/9/213},
Key = {fds248506}
}
@article{fds248505,
Author = {Thomas, JE},
Title = {Ultracold Fermi gas on a chip},
Journal = {Nature Physics},
Volume = {2},
Number = {6},
Pages = {377-378},
Publisher = {Springer Science and Business Media LLC},
Year = {2006},
Month = {June},
ISSN = {1745-2473},
url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000238529600017&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
Doi = {10.1038/nphys326},
Key = {fds248505}
}
@article{fds52329,
Author = {J. E. Thomas and J. Joseph and B. Clancy and L. Luo and J. Kinast and A. Turlapov},
Title = {Optical trapping and fundamental studies of atomic Fermi
gases},
Volume = {6326},
Pages = {632602},
Booktitle = {Proceedings of the SPIE},
Year = {2006},
Key = {fds52329}
}
@article{fds52299,
Author = {J. E. Thomas and J. Kinast and A. Turlapov},
Title = {Universal thermodynamics of a strongly interacting Fermi
gas},
Volume = {850},
Pages = {69-76},
Booktitle = {AIP Conference Proceedings},
Publisher = {AIP},
Editor = {Y. Takano and S. P. Hershfield and S. O. Hill and P. J. Hirshfeld and A. M. Goldman},
Year = {2006},
Key = {fds52299}
}
@article{fds248501,
Author = {Thomas, JE},
Title = {Optically-trapped Fermi gases},
Journal = {Habitation},
Volume = {10},
Pages = {242},
Year = {2006},
Key = {fds248501}
}
@article{fds248508,
Author = {Kinast, J and Turlapov, A and Thomas, JE},
Title = {Optically trapped Fermi gases model strong interactions in
nature},
Journal = {Optics and Photonics News},
Volume = {16},
Number = {12 SPEC. ISS.},
Pages = {21},
Publisher = {The Optical Society},
Year = {2005},
Month = {December},
url = {http://dx.doi.org/10.1364/OPN.16.12.000021},
Abstract = {Strongly interacting Fermi gases are produced in an optical
trap, by using a magnetic field to tune them to a
collisional resonance. In this regime, the gas exhibits
remarkable properties, such as highly anisotropic expansion,
universal thermodynamics, and high-temperature
superfluidity. An amazing similarity between the elliptic
flow observed in experiments at RHIC and the anisotropic
expansion of an ultracold, strongly interacting Fermi gas of
6Li atoms at temperatures 20 orders of magnitude colder was
also noticed. These fermi gases permit studies of
hydrodynamic flow over a wide range of temperatures,
including both superfluid and strongly collisional
regimes.},
Doi = {10.1364/OPN.16.12.000021},
Key = {fds248508}
}
@article{fds248507,
Author = {Lu, ZH and Thomas, JE and Bali, S},
Title = {Observation of phase-sensitive temporal correlations in the
resonance fluorescence from two-level atoms.},
Journal = {Optics letters},
Volume = {30},
Number = {18},
Pages = {2478-2480},
Year = {2005},
Month = {September},
ISSN = {0146-9592},
url = {http://www.ncbi.nlm.nih.gov/pubmed/16196358},
Abstract = {We have made what we believe is the first observation of
phase-dependent temporal correlations in the fluorescent
field emitted by coherently driven two-level atoms in free
space. We measured the temporal fluctuations of the
fluorescent field when the resonant driving field was in
phase and out of phase with the local-oscillator
field.},
Doi = {10.1364/ol.30.002478},
Key = {fds248507}
}
@article{fds248509,
Author = {Reil, F and Thomas, JE},
Title = {Observation of phase conjugation of light arising from
enhanced backscattering in a random medium.},
Journal = {Physical review letters},
Volume = {95},
Number = {14},
Pages = {143903},
Year = {2005},
Month = {September},
ISSN = {0031-9007},
url = {http://www.ncbi.nlm.nih.gov/pubmed/16241655},
Abstract = {We measure the fundamental phase conjugation of a light
field arising from enhanced backscattering in a multiple
scattering medium. The measurements employ a two-window,
time-resolved heterodyne method to suppress specularly
reflected light and to determine the transverse Wigner
function of the field, yielding joint amplitude and phase
information. Using this method, a light field backscattered
from an aqueous suspension of polystyrene spheres is found
to reverse curvature relative to that of the incident
field.},
Doi = {10.1103/physrevlett.95.143903},
Key = {fds248509}
}
@article{fds248512,
Author = {Thomas, JE and Kinast, J and Turlapov, A},
Title = {Virial theorem and universality in a unitary fermi
gas.},
Journal = {Physical review letters},
Volume = {95},
Number = {12},
Pages = {120402},
Year = {2005},
Month = {September},
ISSN = {0031-9007},
url = {http://www.ncbi.nlm.nih.gov/pubmed/16197054},
Abstract = {Unitary Fermi gases, where the scattering length is large
compared to the interparticle spacing, can have universal
properties, which are independent of the details of the
interparticle interactions when the range of the scattering
potential is negligible. We prepare an optically trapped,
unitary Fermi gas of 6Li, tuned just above the center of a
broad Feshbach resonance. In agreement with the universal
hypothesis, we observe that this strongly interacting
many-body system obeys the virial theorem for an ideal gas
over a wide range of temperatures. Based on this result, we
suggest a simple volume thermometry method for unitary
gases. We also show that the observed breathing mode
frequency, which is close to the unitary hydrodynamic value
over a wide range of temperature, is consistent with a
universal hydrodynamic gas with nearly isentropic
dynamics.},
Doi = {10.1103/physrevlett.95.120402},
Key = {fds248512}
}
@article{fds248511,
Author = {Kinast, J and Turlapov, A and Thomas, JE},
Title = {Damping of a unitary Fermi gas.},
Journal = {Physical review letters},
Volume = {94},
Number = {17},
Pages = {170404},
Year = {2005},
Month = {May},
ISSN = {0031-9007},
url = {http://www.ncbi.nlm.nih.gov/pubmed/15904273},
Abstract = {We measure the temperature dependence of the radial
breathing mode in an optically trapped, unitary Fermi gas of
6Li, just above the center of a broad Feshbach resonance.
The damping rate reveals a clear change in behavior which we
interpret as arising from a superfluid transition. We
suggest pair breaking as a mechanism for an increase in the
damping rate which occurs at temperatures well above the
transition. In contrast to the damping, the frequency varies
smoothly and remains close to the unitary hydrodynamic
value. At low temperature T, the damping depends on the atom
number only through the reduced temperature, and
extrapolates to 0 at T = 0.},
Doi = {10.1103/physrevlett.94.170404},
Key = {fds248511}
}
@article{fds248510,
Author = {Kinast, J and Turlapov, A and Thomas, JE and Chen, Q and Stajic, J and Levin, K},
Title = {Heat capacity of a strongly interacting Fermi
gas.},
Journal = {Science (New York, N.Y.)},
Volume = {307},
Number = {5713},
Pages = {1296-1299},
Year = {2005},
Month = {February},
url = {http://www.ncbi.nlm.nih.gov/pubmed/15681340},
Abstract = {We have measured the heat capacity of an optically trapped,
strongly interacting Fermi gas of atoms. A precise addition
of energy to the gas is followed by single-parameter
thermometry, which determines the empirical temperature
parameter of the gas cloud. Our measurements reveal a clear
transition in the heat capacity. The energy and the spatial
profile of the gas are computed using a theory of the
crossover from Fermi to Bose superfluids at finite
temperatures. The theory calibrates the empirical
temperature parameter, yields excellent agreement with the
data, and predicts the onset of superfluidity at the
observed transition point.},
Doi = {10.1126/science.1109220},
Key = {fds248510}
}
@article{fds248515,
Author = {Kinast, J and Turlapov, A and Thomas, JE},
Title = {Breakdown of hydrodynamics in the radial breathing mode of a
strongly interacting Fermi gas},
Journal = {Physical Review A - Atomic, Molecular, and Optical
Physics},
Volume = {70},
Number = {5 A},
Pages = {051401(R)},
Publisher = {American Physical Society (APS)},
Year = {2004},
Month = {November},
ISSN = {1050-2947},
url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000225479000008&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
Abstract = {The magnetic-field dependence of the frequency and damping
time for the radial breathing mode of an optically trapped
Fermi gas of 6Li atoms near a Feshbach resonance was
investigated. For fields near 1080 G, a breakdown of
hydrodynamic behavior was observed, which was manifested by
a sharp increase in frequency and damping rate. It was
observed that when the Feshbach molecular state in the
singlet potential has a higher energy than the two-particle
Fermi energy, the system becomes BCS-like. The results show
that at higher fields near 925 G, the frequency decreased,
and an abrupt frequency increased at a field of 1080 G,
accompanied by rapid damping.},
Doi = {10.1103/PhysRevA.70.051401},
Key = {fds248515}
}
@article{fds248516,
Author = {Kinast, J and Hemmer, SL and Gehm, ME and Turlapov, A and Thomas,
JE},
Title = {Evidence for superfluidity in a resonantly interacting Fermi
gas.},
Journal = {Physical review letters},
Volume = {92},
Number = {15},
Pages = {150402},
Year = {2004},
Month = {April},
ISSN = {0031-9007},
url = {http://www.ncbi.nlm.nih.gov/pubmed/15169270},
Abstract = {We observe collective oscillations of a trapped, degenerate
Fermi gas of 6Li atoms at a magnetic field just above a
Feshbach resonance, where the two-body physics does not
support a bound state. The gas exhibits a radial breathing
mode at a frequency of 2837(05) Hz, in excellent agreement
with the frequency of nu(H) identical with
sqrt[10nu(x)nu(y)/3]=2830(20) Hz predicted for a
hydrodynamic Fermi gas with unitarity-limited interactions.
The measured damping times and frequencies are inconsistent
with predictions for both the collisionless mean field
regime and for collisional hydrodynamics. These observations
provide the first evidence for superfluid hydrodynamics in a
resonantly interacting Fermi gas.},
Doi = {10.1103/physrevlett.92.150402},
Key = {fds248516}
}
@article{fds248514,
Author = {Lee, KF and Thomas, JE},
Title = {Entanglement with classical fields},
Journal = {Physical Review A - Atomic, Molecular, and Optical
Physics},
Volume = {69},
Number = {5 A},
Pages = {052311},
Publisher = {American Physical Society (APS)},
Year = {2004},
Month = {January},
ISSN = {1050-2947},
url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000221813700049&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
Abstract = {A simple classical-field optical heterodyne method which
employs postselection to reproduce the polarization
correlations of four-particle entangled state was
experimentally analyzed. A heuristic argument relating this
method to the measurement of multiple quantum fields by
correlated homodyne detection was given. The polarization
correlations of the 32 elements in the truth table from the
quantum mechanical Greenberger-Horne-Zeilinger experiments
on the violation of local realism were reproduced. A form of
classical entanglement swapping in a four-particle basis was
also demonstrated.},
Doi = {10.1103/PhysRevA.69.052311},
Key = {fds248514}
}
@article{fds248513,
Author = {Thomas, J and Gehm, M},
Title = {Optically Trapped Fermi Gases},
Journal = {American Scientist},
Volume = {92},
Number = {3},
Pages = {238-238},
Publisher = {Sigma Xi},
Year = {2004},
ISSN = {0003-0996},
url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000220792000020&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
Doi = {10.1511/2004.47.930},
Key = {fds248513}
}
@article{fds303754,
Author = {Gehm, ME and Hemmer, SL and O’Hara, KM and Thomas,
JE},
Title = {Unitarity-limited elastic collision rate in a harmonically
trapped Fermi gas},
Journal = {Physical Review A - Atomic, Molecular, and Optical
Physics},
Volume = {68},
Number = {1},
Pages = {4},
Publisher = {American Physical Society (APS)},
Year = {2003},
Month = {January},
url = {http://arxiv.org/abs/cond-mat/0304633v1},
Abstract = {We derive the elastic collision rate for a harmonically
trapped Fermi gas in the extreme unitarity limit where the
s-wave scattering cross section is [Formula Presented] with
[Formula Presented] the relative momentum. The collision
rate is given in the form [Formula Presented]—the product
of a universal collision rate [Formula Presented] and a
dimensionless function of the ratio of the temperature T to
the Fermi temperature [Formula Presented] We find that I has
a peak value of [Formula Presented] at [Formula Presented]
[Formula Presented] for [Formula Presented] and [Formula
Presented] for [Formula Presented] We estimate the collision
rate for recent experiments on a strongly-interacting
degenerate Fermi gas of atoms. © 2003 The American Physical
Society.},
Doi = {10.1103/PhysRevA.68.011603},
Key = {fds303754}
}
@article{fds303755,
Author = {Gehm, ME and Hemmer, SL and Granade, SR and O’Hara, KM and Thomas,
JE},
Title = {Mechanical stability of a strongly interacting Fermi gas of
atoms},
Journal = {Physical Review A - Atomic, Molecular, and Optical
Physics},
Volume = {68},
Number = {1},
Pages = {4},
Publisher = {American Physical Society (APS)},
Year = {2003},
Month = {January},
url = {http://arxiv.org/abs/cond-mat/0212499v2},
Abstract = {A strongly attractive, two-component Fermi gas of atoms
exhibits universal behavior and should be mechanically
stable as a consequence of the quantum-mechanical
requirement of unitarity. This requirement limits the
maximum attractive force to a value smaller than that of the
outward Fermi pressure. To experimentally demonstrate this
stability, we use all-optical methods to produce a highly
degenerate, two-component gas of [Formula Presented] atoms
in an applied magnetic field near a Feshbach resonance,
where strong interactions are observed. We find that gas is
stable at densities far exceeding that predicted previously
for the onset of mechanical instability. Further, we provide
a temperature-corrected measurement of an important,
universal, many-body parameter, which determines the
stability—the mean-field contribution to the chemical
potential in units of the local Fermi energy. © 2003 The
American Physical Society.},
Doi = {10.1103/PhysRevA.68.011401},
Key = {fds303755}
}
@article{fds248517,
Author = {Thomas, JE and Hemmer, SL and Kinast, J and Turlapov, A and Gehm, ME and O'Hara, KM},
Title = {Dynamics of a highly-degenerate, strongly-interacting Fermi
gas of atoms},
Journal = {Journal of Low Temperature Physics},
Volume = {104},
Number = {1-2},
Pages = {655-664},
Publisher = {World Scientific},
Year = {2003},
url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000229968900021&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
Abstract = {We use all-optical methods to produce a highly-degenerate,
Fermi gas of 6 Li atoms near a Feshbach resonance, where
strong interactions are predicted. In this regime, the
zero-energy scattering length is larger than the
interparticle spacing, and both the mean field energy and
the collision rate take on universal forms as a consequence
of unitarity and many-body interactions. Our experiments
study universal hydrodynamic expansion of the gas and
universal mean field interactions. By measuring the cloud
radii of the trapped gas, we determine a universal parameter
for strongly interacting two-component Fermi systems, the
ratio of the mean field energy to the kinetic energy. ©
2004 Plenum Publishing Corporation.},
Doi = {10.1023/b:jolt.0000012624.69815.77},
Key = {fds248517}
}
@article{fds248538,
Author = {O'Hara, KM and Hemmer, SL and Gehm, ME and Granade, SR and Thomas,
JE},
Title = {Observation of a strongly interacting degenerate Fermi gas
of atoms.},
Journal = {Science (New York, N.Y.)},
Volume = {298},
Number = {5601},
Pages = {2179-2182},
Year = {2002},
Month = {December},
url = {http://www.ncbi.nlm.nih.gov/pubmed/12424386},
Abstract = {We report on the observation of a highly degenerate,
strongly interacting Fermi gas of atoms. Fermionic lithium-6
atoms in an optical trap are evaporatively cooled to
degeneracy using a magnetic field to induce strong, resonant
interactions. Upon abruptly releasing the cloud from the
trap, the gas is observed to expand rapidly in the
transverse direction while remaining nearly stationary in
the axial direction. We interpret the expansion dynamics in
terms of collisionless superfluid and collisional
hydrodynamics. For the data taken at the longest evaporation
times, we find that collisional hydrodynamics does not
provide a satisfactory explanation, whereas superfluidity is
plausible.},
Doi = {10.1126/science.1079107},
Key = {fds248538}
}
@article{fds248537,
Author = {Lee, KF and Thomas, JE},
Title = {Experimental simulation of two-particle quantum entanglement
using classical fields.},
Journal = {Physical review letters},
Volume = {88},
Number = {9},
Pages = {097902},
Year = {2002},
Month = {March},
ISSN = {0031-9007},
url = {http://www.ncbi.nlm.nih.gov/pubmed/11864055},
Abstract = {We experimentally demonstrate simulation of two entangled
quantum bits using classical fields of two frequencies and
two polarizations. Multiplication of optical heterodyne beat
signals from two spatially separated regions simulates
coincidence detection of two particles. The product signal
so obtained contains several frequency components, one of
which can be selected by bandpass frequency filtering. The
bandpassed signal contains two indistinguishable,
interfering contributions, permitting simulation of four
polarization-entangled Bell-like states. These classical
field methods may be useful in small scale simulations of
quantum logic operations that require multiparticle
entanglement without collapse.},
Doi = {10.1103/physrevlett.88.097902},
Key = {fds248537}
}
@article{fds248539,
Author = {Granade, SR and Gehm, ME and O'Hara, KM and Thomas,
JE},
Title = {All-optical production of a degenerate Fermi
gas.},
Journal = {Physical review letters},
Volume = {88},
Number = {12},
Pages = {120405},
Year = {2002},
Month = {March},
ISSN = {0031-9007},
url = {http://www.ncbi.nlm.nih.gov/pubmed/11909435},
Abstract = {We achieve degeneracy in a mixture of the two lowest
hyperfine states of 6Li by direct evaporation in a CO2 laser
trap, yielding the first all optically produced degenerate
Fermi gas. More than 10(5) atoms are confined at
temperatures below 4 microK at full trap depth, where the
Fermi temperature for each state is 8 microK. This
degenerate two-component mixture is ideal for exploring
mechanisms of superconductivity ranging from Cooper pairing
to Bose-Einstein condensation of strongly bound
pairs.},
Doi = {10.1103/physrevlett.88.120405},
Key = {fds248539}
}
@article{fds303757,
Author = {O’Hara, KM and Hemmer, SL and Granade, SR and Gehm, ME and Thomas, JE and Venturi, V and Tiesinga, E and Williams, CJ},
Title = {Measurement of the zero crossing in a Feshbach resonance of
fermionic [Formula Presented]},
Journal = {Physical Review A - Atomic, Molecular, and Optical
Physics},
Volume = {66},
Number = {4},
Pages = {4},
Publisher = {American Physical Society (APS)},
Year = {2002},
Month = {January},
url = {http://arxiv.org/abs/cond-mat/0207717v1},
Abstract = {We measure a zero crossing in the scattering length of a
mixture of the two lowest hyperfine states of [Formula
Presented] To locate the zero crossing, we monitor the
decrease in temperature and atom number arising from
evaporation in a [Formula Presented] laser trap as a
function of magnetic field B. The temperature decrease and
atom loss are minimized for [Formula Presented] consistent
with no evaporation. We also present preliminary
calculations using potentials that have been constrained by
the measured zero crossing and locate a broad Feshbach
resonance at [Formula Presented] in agreement with previous
theoretical predictions. In addition, our theoretical model
predicts a second and much narrower Feshbach resonance near
55 mT. 5555 2002 The American Physical Society.},
Doi = {10.1103/PhysRevA.66.041401},
Key = {fds303757}
}
@article{fds4968,
Author = {F. Reil and J. E. Thomas},
Title = {Time-resolved, two-window measurement of Wigner functions
for coherent backscatter from a turbid medium},
Journal = {Proc. SPIE},
Volume = {4705},
Pages = {22-29},
Booktitle = {Saratov Fall Meeting 2001: Coherent Optics of Ordered and
Random Media II},
Editor = {Dmitry A. Zimnyakov},
Year = {2002},
Key = {fds4968}
}
@article{fds4969,
Author = {S. R. Granade and M. E. Gehm and K. M. O’Hara and J.E.
Thomas},
Title = {Preparation of a degenerate, two-component Fermi gas by
evaporation in a single beam optical trap},
Volume = {74},
Series = {Postconference Edition},
Pages = {169-170},
Booktitle = {OSA Trends in Optics and Photonics (TOPS) Quantum
Electronics and Laser Science Conference (QELS 2002), OSA
Technical Digest},
Publisher = {Optical Society of America, Washington, D.C.},
Year = {2002},
Key = {fds4969}
}
@article{fds4971,
Author = {J. E. Thomas and S. R. Granade and M. E. Gehm and M.-S. Chang and K.
M. O’Hara},
Title = {Optical trapping of a two-component Fermi
gas},
Pages = {46-54},
Booktitle = {Proceedings of the XV International Conference on Laser
Spectroscopy},
Publisher = {World Scientific, New Jersey},
Editor = {S. Chu and V. Vuletic and A. J. Kerman and C.
Chin},
Year = {2002},
Key = {fds4971}
}
@article{fds4963,
Author = {K. M. O’Hara and S. R. Granade and M. E. Gehm and M.-S. Chang and J. E. Thomas},
Title = {Modeling the evaporative cooling of fermionic atoms in an
optical trap},
Journal = {OSA Trends in Optics and Photonics (TOPS)},
Volume = {57},
Series = {Postconference Edition},
Pages = {253},
Booktitle = {Quantum Electronics and Laser Science Conference (QELS
2001), Technical Digest},
Publisher = {Optical Society of America, Washington, DC,},
Year = {2001},
Key = {fds4963}
}
@article{fds4964,
Author = {M. E. Gehm and S. R. Granade and M.-S. Chang and K. M. O’Hara and J.E. Thomas},
Title = {Optically trapped Fermi gas},
Volume = {57},
Series = {Postconference Edition},
Pages = {253-254},
Booktitle = {OSA Trends in Optics and Photonics Quantum Electronics and
Laser Science Conference},
Publisher = {Optical Society of America, Washington, DC},
Year = {2001},
Key = {fds4964}
}
@article{fds4965,
Author = {K. F. Lee and F. Reil and J.E. Thomas},
Title = {Classical-wave analogs of quantum measurement},
Volume = {57},
Series = {Postconference Edition},
Pages = {62-63},
Booktitle = {OSA Trends in Optics and Photonics (TOPS) Quantum
Electronics and Laser Science Conference (QELS 2001),
Technical Digest},
Publisher = {Optical Society of America, Washington, D.C.},
Year = {2001},
Key = {fds4965}
}
@article{fds4966,
Author = {F. Reil and K. F. Lee and J.E. Thomas},
Title = {Two-window heterodyne methods for measurement of optical
coherence in multiple scattering media},
Volume = {57},
Series = {Postconference edition},
Pages = {145-146},
Booktitle = {OSA Trends in Optics and Photonics (TOPS) Quantum
Electronics and Laser Science Conference (QELS 2001),
Technical Digest},
Publisher = {Optical Society of America, Washington, DC},
Year = {2001},
Key = {fds4966}
}
@article{fds248518,
Author = {O’Hara, KM and Thomas, JE},
Title = {Standing room only at the quantum scale},
Journal = {Science},
Volume = {291},
Number = {5513},
Pages = {2556},
Year = {2001},
url = {http://dx.doi.org/10.1126/science.1060025},
Doi = {10.1126/science.1060025},
Key = {fds248518}
}
@article{fds248519,
Author = {O’Hara, KM and Gehm, ME and Granade, SR and Thomas,
JE},
Title = {Scaling laws for evaporative cooling in time-dependent
optical traps},
Journal = {Phys. Rev. A},
Volume = {64},
Number = {5},
Pages = {051403(R)},
Publisher = {American Physical Society (APS)},
Year = {2001},
ISSN = {1050-2947},
url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000172074200006&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
Abstract = {We derive scaling laws for the number of atoms, collision
rate, and phase-space density as a function of trap depth
for evaporative cooling in an adiabadically lowered optical
trap. The results are in excellent agreement with a
Boltzmann equation model and show that very large increases
in phase-space density can be obtained without excessive
slowing of the evaporation rate. Predictions are in
reasonable agreement with a recent experiment that achieves
Bose-Einstein condensation by evaporation in an optical
trap. We also discuss evaporation of fermionic mixtures and
explain why Pauli blocking does not strongly inhibit
cooling. © 2001 The American Physical Society.},
Doi = {10.1103/PhysRevA.64.051403},
Key = {fds248519}
}
@article{fds248520,
Author = {O’Hara, KM and Granade, SR and Gehm, ME and Thomas,
JE},
Title = {Loading Dynamics of CO2 Laser Traps},
Journal = {Phys. Rev. A},
Volume = {63},
Number = {4},
Pages = {043403},
Year = {2001},
ISSN = {1050-2947},
url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000168095300076&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
Abstract = {We present a simple Fokker-Planck model for the evolution of
the number of atoms and the spatial distribution in a CO2
laser trap which is loaded from a magneto-optical trap
(MOT). Deep CO2 laser traps can achieve very high densities,
but reach equilibrium slowly compared to shallow traps.
Equilibrium times range from milliseconds for shallow traps
to seconds in traps which are deep compared to the thermal
energy. A universal function for the maximum number of
trapped atoms is given, assuming that the optical dipole
trap reaches thermal equilibrium with the MOT. ©2001 The
American Physical Society.},
Doi = {10.1103/PhysRevA.63.043403},
Key = {fds248520}
}
@article{fds248521,
Author = {O'Hara, KM and Gehm, ME and Granade, SR and Bali, S and Thomas,
JE},
Title = {Stable, strongly attractive, two-state mixture of lithium
fermions in an optical trap},
Journal = {Physical review letters},
Volume = {85},
Number = {10},
Pages = {2092-2095},
Year = {2000},
Month = {September},
url = {http://www.ncbi.nlm.nih.gov/pubmed/10970470},
Abstract = {We use an all-optical trap to confine a strongly attractive
two-state mixture of lithium fermions. By measuring the rate
of evaporation from the trap, we determine the effective
elastic scattering cross section 4pia(2) to show that the
magnitude of the scattering length |a| is very large, in
agreement with predictions. We show that the mixture is
stable against inelastic decay provided that a small bias
magnetic field is applied. For this system, the s-wave
interaction is widely tunable at low magnetic field, and can
be turned on and off rapidly via a Raman pi pulse. Hence,
this mixture is well suited for fundamental studies of an
interacting Fermi gas.},
Doi = {10.1103/physrevlett.85.2092},
Key = {fds248521}
}
@article{fds4954,
Author = {A. Wax and F. Reil and K. F. Lee and S. Bali and J. E.
Thomas},
Title = {Time-resolved optical phase space distributions for coherent
backscatter},
Journal = {Proc. SPIE},
Volume = {4001},
Pages = {130-134},
Booktitle = {Saratov Fall Meeting ‘99: Optical Technologies in
Biophysics and Medicine},
Editor = {Valery V. Tuchin and Dmitry A Zimnyakov and Alexander B.
Pravdin},
Year = {2000},
Key = {fds4954}
}
@article{fds4959,
Author = {J. E. Thomas and F. Reil and K. F. Lee and A. Wax and S.
Bali},
Title = {Wigner Phase Space Distributions and Coherence
Tomography},
Journal = {to appear in Proc. SPIE},
Volume = {3914},
Year = {2000},
Key = {fds4959}
}
@article{fds4960,
Author = {J. E. Thomas and F. Reil and K. F Lee and A. Wax and S.
Bali},
Title = {Wigner Phase Space Distributions and Coherence
Tomography},
Journal = {Proc. SPIE},
Volume = {3927},
Pages = {147-155},
Booktitle = {Optical Pulse and Beam Propagation II},
Editor = {Yehuda B Band},
Year = {2000},
Key = {fds4960}
}
@article{fds248522,
Author = {Wax, A and Bali, S and Thomas, JE},
Title = {Path-length-resolved optical phase space distributions for
enhanced backscatter},
Journal = {Phys. Rev. Lett.},
Volume = {85},
Pages = {66},
Year = {2000},
Key = {fds248522}
}
@article{fds248524,
Author = {Lee, KF and Reil, F and Bali, S and Wax, A and Thomas,
JE},
Title = {Heterodyne measurement of Wigner distributions for classical
optical fields.},
Journal = {Optics letters},
Volume = {24},
Number = {19},
Pages = {1370-1372},
Year = {1999},
Month = {October},
ISSN = {0146-9592},
url = {http://dx.doi.org/10.1364/ol.24.001370},
Abstract = {We demonstrate a two-window heterodyne method for measuring
the x-p cross correlation, ??(*)(x)? (p)?, of an optical
field ? for transverse position x and transverse momentum p.
This scheme permits independent control of the x and p
resolution. A simple linear transform of the x-p correlation
function yields the Wigner phase-space distribution. This
technique is useful for both coherent and low-coherence
light sources and may permit new biological imaging
techniques based on transverse coherence measurement with
time gating. We point out an interesting analogy between x-p
correlation measurements for classical-wave and quantum
fields.},
Doi = {10.1364/ol.24.001370},
Key = {fds248524}
}
@article{fds248526,
Author = {Wax, A and Bali, S and Thomas, JE},
Title = {Optical phase-space distributions for low-coherence
light.},
Journal = {Optics letters},
Volume = {24},
Number = {17},
Pages = {1188-1190},
Year = {1999},
Month = {September},
ISSN = {0146-9592},
url = {http://dx.doi.org/10.1364/ol.24.001188},
Abstract = {Using a novel heterodyne technique, we measure optical
phase-space distributions in momentum and position for
low-coherence light. Quantitative information is obtained
simultaneously about the longitudinal and the transverse
coherence properties as well as the wave-front curvature of
the light field. This method can be used to monitor these
optical parameters directly for signal fields scattered from
samples of interest, for tomographic imaging.},
Doi = {10.1364/ol.24.001188},
Key = {fds248526}
}
@article{fds4946,
Author = {A. Wax and J. E. Thomas},
Title = {Measurement of Smoothed Wigner Phase Space Distributions for
Low-Coherence Light in Multiple Scattering
Media},
Journal = {Proc. SPIE},
Volume = {3598},
Pages = {2},
Booktitle = {Coherence Domain Optical Methods in Biomedical Science and
Clinical Applications III},
Editor = {Valery V. Tuchin and Joseph A. Izatt},
Year = {1999},
Month = {January},
Key = {fds4946}
}
@article{fds303756,
Author = {O’hara, KM and Granade, SR and Gehm, ME and Savard, TA and Bali, S and Freed, C and Thomas, JE},
Title = {Ultrastable CO2laser trapping of lithium
fermions},
Journal = {Physical Review Letters},
Volume = {82},
Number = {21},
Pages = {4204-4207},
Publisher = {American Physical Society (APS)},
Year = {1999},
Month = {January},
url = {http://arxiv.org/abs/physics/0003049v1},
Abstract = {We demonstrate an ultrastable CO2laser trap that provides
tight confinement of neutral atoms with negligible optical
scattering and minimal laser-noise-induced heating. Using
this method, fermionic6Li atoms are stored in a 0.4 mK deep
well with a 1/e trap lifetime of 300 sec, consistent with a
background pressure of 10-11Torr. To our knowledge, this is
the longest storage time ever achieved with an all-optical
trap, comparable to the best reported magnetic traps. ©
1999 The American Physical Society.},
Doi = {10.1103/PhysRevLett.82.4204},
Key = {fds303756}
}
@article{fds4947,
Author = {A. Wax and J. E. Thomas},
Title = {Optical Phase Space Distributions for Low Coherence Light in
Turbid Media},
Series = {OSA Technical Digest Series},
Booktitle = {Conference on Lasers and Electro-Optics},
Publisher = {Optical Society of America},
Year = {1999},
Key = {fds4947}
}
@article{fds248523,
Author = {Wax, A and Bali, S and Alphonse, GA and Thomas, JE},
Title = {Characterizing the coherence of broadband sources using
optical phase space contours},
Journal = {J. Biomed. Opt.},
Volume = {4},
Pages = {1-8},
Year = {1999},
Key = {fds248523}
}
@article{fds248525,
Author = {Savard, TA and Granade, SR and O’Hara, KM and Gehm, ME and Thomas,
JE},
Title = {Raman-induced magnetic resonance imaging of atoms in a
magneto-optical trap},
Journal = {Phys. Rev. A},
Volume = {60},
Number = {6},
Pages = {4788},
Publisher = {American Physical Society (APS)},
Year = {1999},
ISSN = {1050-2947},
url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000084148000074&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
Abstract = {We apply Raman-induced resonance imaging techniques to
determine, with a spatial resolution of 12 [Formula
Presented] the size of a cloud of atoms in a magneto-optical
trap and the location of the centroid with respect to the
magnetic-field zero point. These experiments provide a
starting point for developing much higher-resolution
resonance imaging methods for cold trapped atoms. © 1999
The American Physical Society.},
Doi = {10.1103/PhysRevA.60.4788},
Key = {fds248525}
}
@article{fds248527,
Author = {Bali, S and O’Hara, KM and Gehm, ME and Granade, SR and Thomas,
JE},
Title = {Quantum-di ractive background gas collisions in atom-trap
heating and loss},
Journal = {Phys. Rev. A},
Volume = {60},
Number = {1},
Pages = {R29},
Publisher = {American Physical Society (APS)},
Year = {1999},
ISSN = {1050-2947},
url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000081247000008&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
Abstract = {We derive a simple formula for the heating rate that arises
from quantum-diffractive background gas collisions in atom
traps. This result appears to explain the residual heating
rates reported for recent experiments with a Cs
vapor-loaded, far-detuned optical trap at [Formula
Presented] Torr [Phys. Rev. Lett. 81, 5768 (1998)].
Diffractive collisions may determine the minimum heating
rates achievable in shallow all-optical or magnetic atom
traps operating at low temperature and high density. © 1999
The American Physical Society.},
Doi = {10.1103/PhysRevA.60.R29},
Key = {fds248527}
}
@article{fds248529,
Author = {Gehm, ME and O’Hara, KM and Savard, TA and Thomas,
JE},
Title = {Noise induced Population Loss in Atom Traps},
Journal = {Bull. Am. Phys. Soc.},
Volume = {44},
Pages = {1153},
Year = {1999},
Key = {fds248529}
}
@article{fds248530,
Author = {Lu, ZH and Bali, S and Thomas, JE},
Title = {Observation of Phase-dependent Temporal Correlations in
Resonance Fluorescence},
Journal = {Bull. Am. Phys. Soc.},
Volume = {44},
Pages = {413},
Year = {1999},
Key = {fds248530}
}
@article{fds248531,
Author = {Lu, ZH and Bali, S and Thomas, JE},
Title = {Observation of squeezing in the phase-dependent fluorescence
spectra of two-level atoms},
Journal = {Physical Review Letters},
Volume = {81},
Number = {17},
Pages = {3635-3638},
Publisher = {American Physical Society (APS)},
Year = {1998},
Month = {October},
ISSN = {0031-9007},
url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000076616000021&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
Abstract = {We observe squeezing in the phase-dependent fluorescence
spectra of two-level atoms that are coherently driven by a
near-resonant laser field in free space. In contrast to
previous predictions that emphasized the in- and
out-of-phase quadratures, we find that maximum squeezing
occurs for homodyne detection at a phase near ±45°
relative to the exciting field. A new physical picture of
phase-dependent noise is developed that incorporates quantum
collapses into a Bloch vector model and yields a very simple
form for the complete squeezing spectrum. © 1998 The
American Physical Society.},
Doi = {10.1103/PhysRevLett.81.3635},
Key = {fds248531}
}
@article{fds4945,
Author = {A. Wax and J. E. Thomas},
Title = {Measurement of Smoothed Wigner Phase Space Distributions for
Coherence Tomography},
Journal = {Proc. SPIE},
Volume = {3726},
Pages = {494},
Booktitle = {International Workshop and Autumn School for Young
Scientists and Students, Light Scattering Technologies for
Mechanics, Biomedical and Material Science},
Publisher = {Saratov, Russia,},
Year = {1998},
Month = {October},
Key = {fds4945}
}
@article{fds4941,
Author = {Z. H. Lu and S. Bali and J. E. Thomas},
Title = {Observation of Squeezing in Free Space Resonance
Fluorescence},
Booktitle = {Proceedings, QCM’98},
Publisher = {Northeastern Univ., Evanston, IL},
Year = {1998},
Month = {August},
Key = {fds4941}
}
@article{fds248535,
Author = {Wax, A and Thomas, JE},
Title = {Measurement of smoothed Wigner phase-space distributions for
small-angle scattering in a turbid medium.},
Journal = {Journal of the Optical Society of America. A, Optics, image
science, and vision},
Volume = {15},
Number = {7},
Pages = {1896-1908},
Year = {1998},
Month = {July},
ISSN = {1084-7529},
url = {http://www.ncbi.nlm.nih.gov/pubmed/9656479},
Abstract = {We study Wigner phase-space distributions W (x, p) in
position (x) and momentum (p) for light undergoing multiple
small-angle scattering in a turbid medium. Smoothed Wigner
phase-space distributions are measured by using a heterodyne
technique that achieves position and momentum resolution
determined by the width and the diffraction angle of the
local oscillator beam. The sample consists of
5.7-micron-radius polystyrene spheres suspended in a
water-glycerol mixture. The momentum distribution of the
transmitted light is found to contain a ballistic peak, a
narrow diffractive pedestal, and a broad background. The
narrow diffractive pedestal is found to decay more slowly
than the ballistic peak as the concentration of scatterers
is increased. The data are in excellent agreement with a
simple theoretical model that explains the behavior of the
narrow pedestal by including multiple diffractive scattering
and treating large-angle scattering as a
loss.},
Doi = {10.1364/josaa.15.001896},
Key = {fds248535}
}
@article{fds4943,
Author = {A. Wax and J.E. Thomas},
Title = {Measurement of Smoothed Wigner Phase Space Distributions in
Multiple Scattering Media},
Volume = {21},
Pages = {348-352},
Booktitle = {OSA Trends in Optics and Photonics, Advances in Optical
Imaging and Photon Migration},
Publisher = {Optical Society of America, Washington, DC},
Editor = {James G. Fujimoto and Michael S. Patterson},
Year = {1998},
Key = {fds4943}
}
@article{fds248532,
Author = {Savard, TA and O’Hara, KM and Granade, SR and Gehm, ME and Thomas,
JE},
Title = {Raman Induced Magnetic Resonance Imaging of Atoms in a
MOT},
Journal = {Bull. Am. Phys. Soc.},
Volume = {43},
Pages = {1292},
Year = {1998},
Key = {fds248532}
}
@article{fds248533,
Author = {Lu, ZH and Bali, S and Thomas, JE},
Title = {Observation of Squeezing in Free Space Phase-Dependent
Resonance Fluorescence},
Journal = {Bull. Am. Phys. Soc.},
Volume = {43},
Pages = {1288},
Year = {1998},
Key = {fds248533}
}
@article{fds248534,
Author = {Gehm, ME and O’Hara, KM and Savard, TA and Thomas,
JE},
Title = {Dynamics of Noise-Induced Heating in Atom
Traps},
Journal = {Phys. Rev. A},
Volume = {58},
Number = {5},
Pages = {3914-3921},
Publisher = {American Physical Society (APS)},
Year = {1998},
ISSN = {1050-2947},
url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000076961300069&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
Abstract = {A Fokker-Planck equation is derived for the energy
distribution of atoms in a three-dimensional harmonic trap
with fluctuations in the spring constant and the equilibrium
position. Using this model, we predict trap lifetimes based
on the measurable noise spectra of the fluctuations. The
energy distributions evolve into a single eigenmode where
the apparent temperature of the distribution remains
constant while the population decays as a consequence of the
energy input. The method of analysis and the corresponding
results are applicable to any optical, magnetic, or ion trap
that is approximately harmonic, and offer useful insights
into both noise-induced and optical heating processes. ©
1998 The American Physical Society.},
Doi = {10.1103/PhysRevA.58.3914},
Key = {fds248534}
}
@article{fds248536,
Author = {Zhao, HZ and Lu, ZH and Bacon, AM and Wang, LJ and Thomas,
JE},
Title = {Precision Measurement of Phase-Dependent Resonance
Fluorescence Spectra},
Journal = {Phys. Rev. A},
Volume = {57},
Number = {2},
Pages = {1427-1447},
Publisher = {American Physical Society (APS)},
Year = {1998},
ISSN = {1050-2947},
url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000071913800096&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
Abstract = {We measure phase-dependent fluorescence spectra for an
elementary system: long-lived coherently driven two-level
atoms in an atomic beam. Phase-dependent fluorescence
spectra measure quadrature noise in the atomic radiation
field. These noise spectra are obtained using a homodyne
detection scheme that suppresses excess noise by subtracting
signals from two identically prepared atomic samples. Noise
spectra are obtained for atomic radiation which is in phase
[Formula Presented] and out of phase [Formula Presented]
with a resonant driving field, as well as [Formula
Presented] out of phase with an off-resonant driving field.
The measured phase-dependent fluorescence spectra are much
richer than ordinary fluorescence spectra, and exhibit many
novel features. Particularly interesting are phase-dependent
noise spectra for off-resonant excitation. These strikingly
exhibit direct manifestations of time ordering, which appear
as large differences between the measured [Formula
Presented] and [Formula Presented] quadrature noise spectra.
The measured noise spectra are in excellent agreement in
magnitude and shape with the results of a quantum treatment
using no free parameters. © 1998 The American Physical
Society.},
Doi = {10.1103/PhysRevA.57.1427},
Key = {fds248536}
}
%% Papers Accepted
@article{fds43817,
Author = {J.E. Thomas and J. Kinast and A. Turlapov},
Title = {Universal thermodynamics of a strongly-interacting Fermi
gas},
Booktitle = {Proceedings of the 24th International Conference on Low
Temperature Physics},
Year = {2005},
Month = {August},
Key = {fds43817}
}
@article{fds43818,
Author = {J.E. Thomas},
Title = {Thermodynamics and mechanical properties of a
strongly-interacting Fermi gas},
Booktitle = {Proceedings of the 17th International Conference on Laser
Spectroscopy},
Year = {2005},
Month = {June},
Key = {fds43818}
}
@article{fds14967,
Author = {J. E. Thomas and S. L. Hemmer and J. M. Kinast and A. V. Turlapov and M.
E. Gehm and K. M. O'Hara},
Title = {Dynamics of a highly-Degenerate, strongly-Interacting Fermi
gas},
Booktitle = {Proceedings of the Sixteenth International Conference on
Laser},
Editor = {H. Bacor and P. Hannaford},
Year = {2003},
Key = {fds14967}
}
@article{fds14968,
Author = {J. E. Thomas and S. L. Hemmer and J. M. Kinast and A. V. Turlapov and M.
E. Gehm and K. M. O'Hara},
Title = {Dynamics of a highly-Degenerate, strongly-Interacting Fermi
gas},
Booktitle = {Proceedings of the Sixteenth International Conference on
Laser},
Editor = {H. Bacor and P. Hannaford},
Year = {2003},
Key = {fds14968}
}
%% Papers Submitted
@article{fds183761,
Author = {J.E. Thomas},
Title = {Unitary Fermi gases},
Booktitle = {Contemporary Concepts of Condensed Matter Science: Ultracold
Bosonic and Fermionic Gases},
Publisher = {Elsevier},
Year = {2010},
Month = {August},
Key = {fds183761}
}
%% Other
@misc{fds166073,
Author = {J.E. Thomas},
Title = {Experiments with Interacting Fermi gases},
Journal = {Bull. Am. Phys. Soc.},
Volume = {54},
Pages = {109},
Year = {2009},
Month = {May},
Key = {fds166073}
}
@misc{fds166074,
Author = {J. E. Thomas and L. Luo and B. Clancy and J. Joseph and Y. Zhang and C.
Cao, X. Du and J. Petricka},
Title = {Fermi Gases with Tunable Interactions},
Pages = {201-212},
Booktitle = {Proceedings of the XXI International Conference on Atomic
Physics},
Publisher = {World Scientific},
Editor = {R. Cote and P. L. Gould and M. Rozman and W. W.
Smith},
Year = {2009},
Month = {April},
Key = {fds166074}
}
@misc{fds152038,
Author = {J. E. Thomas and L. Luo and B. Clancy and J. Joseph and Y. Zhang and C.
Cao, X. Du and J. Petricka},
Title = {Fermi Gases with Tunable Interactions},
Booktitle = {Conference proceedings, ICAP 2008},
Year = {2008},
Month = {June},
Key = {fds152038}
}