



@article {1782,
	title = {Sudden-quench dynamics of Bardeen-Cooper-Schrieffer states in deep optical lattices},
	journal = {Physical Review A},
	volume = {94},
	year = {2016},
	month = {2016/08/05},
	pages = {023607},
	abstract = {<p>We determine the exact time evolution of an initial Bardeen-Cooper-Schrieffer (BCS) state of ultra-cold atoms in a hexagonal optical lattice. The dynamical evolution is triggered by ramping the lattice potential up, such that the interaction strength Uf is much larger than the hopping amplitude Jf. The quench initiates collective oscillations with frequency |Uf|/(2π) in the momentum occupation numbers and imprints an oscillating phase with the same frequency on the order parameter Δ. The latter is not reproduced by treating the time evolution in mean-field theory. The momentum density-density or noise correlation functions oscillate at frequency |Uf|/2π as well as its second harmonic. For a very deep lattice, with negligible tunneling energy, the oscillations of momentum occupation numbers are undamped. Non-zero tunneling after the quench leads to dephasing of the different momentum modes and a subsequent damping of the oscillations. This occurs even for a finite-temperature initial BCS state, but not for a non-interacting Fermi gas. We therefore propose to use this dephasing to detect a BCS state. Finally, we predict that the noise correlation functions in a honeycomb lattice will develop strong anti-correlations near the Dirac point.</p>},
	doi = {http://dx.doi.org/10.1103/PhysRevA.94.023607},
	url = {http://arxiv.org/abs/1602.00979},
	author = {Marlon Nuske and L. Mathey and Eite Tiesinga}
}
@article {1282,
	title = {Optimization of collisional Feshbach cooling of an ultracold  nondegenerate gas},
	journal = {Physical Review A},
	volume = {91},
	year = {2015},
	month = {2015/04/20},
	pages = {043626},
	abstract = {  We optimize a collision-induced cooling process for ultracold atoms in the
nondegenerate regime. It makes use of a Feshbach resonance, instead of rf
radiation in evaporative cooling, to selectively expel hot atoms from a trap.
Using functional minimization we analytically show that for the optimal cooling
process the resonance energy must be tuned such that it linearly follows the
temperature. Here, optimal cooling is defined as maximizing the phase-space
density after a fixed cooling duration. The analytical results are confirmed by
numerical Monte-Carlo simulations. In order to simulate more realistic
experimental conditions, we show that background losses do not change our
conclusions, while additional non-resonant two-body losses make a lower initial
resonance energy with non-linear dependence on temperature preferable.
},
	doi = {10.1103/PhysRevA.91.043626},
	url = {http://arxiv.org/abs/1412.8473v1},
	author = {Marlon Nuske and Eite Tiesinga and L. Mathey}
}
@article {1303,
	title = {Detecting paired and counterflow superfluidity via dipole oscillations},
	journal = {Physical Review A},
	volume = {84},
	year = {2011},
	month = {2011/10/27},
	abstract = {  We suggest an experimentally feasible procedure to observe paired and
counterflow superfluidity in ultra-cold atom systems. We study the time
evolution of one-dimensional mixtures of bosonic atoms in an optical lattice
following an abrupt displacement of an additional weak confining potential. We
find that the dynamic responses of the paired superfluid phase for attractive
inter-species interactions and the counterflow superfluid phase for repulsive
interactions are qualitatively distinct and reflect the quasi long-range order
that characterizes these states. These findings suggest a clear experimental
procedure to detect these phases, and give an intuitive insight into their
dynamics.
},
	doi = {10.1103/PhysRevA.84.041609},
	url = {http://arxiv.org/abs/1103.3513v3},
	author = {Anzi Hu and L. Mathey and Eite Tiesinga and Ippei Danshita and Carl J. Williams and Charles W. Clark}
}
@article {1413,
	title = {Noise correlations of one-dimensional Bose mixtures in optical lattices},
	journal = {Physical Review A},
	volume = {81},
	year = {2010},
	month = {2010/6/2},
	abstract = {  We study the noise correlations of one-dimensional binary Bose mixtures, as a
probe of their quantum phases. In previous work, we found a rich structure of
many-body phases in such mixtures, such as paired and counterflow
superfluidity. Here we investigate the signature of these phases in the noise
correlations of the atomic cloud after time-of-flight expansion, using both
Luttinger liquid theory and the time-evolving block decimation (TEBD) method.
We find that paired and counterflow superfluidity exhibit distinctive features
in the noise spectra. We treat both extended and inhomogeneous systems, and our
numerical work shows that the essential physics of the extended systems is
present in the trapped-atom systems of current experimental interest. For
paired and counterflow superfluid phases, we suggest methods for extracting
Luttinger parameters from noise correlation spectroscopy.
},
	doi = {10.1103/PhysRevA.81.063602},
	url = {http://arxiv.org/abs/1002.4918v2},
	author = {Anzi Hu and L. Mathey and Carl J. Williams and Charles W. Clark}
}
@article {1293,
	title = {Collisional cooling of ultra-cold atom ensembles using Feshbach  resonances
},
	journal = {Physical Review A},
	volume = {80},
	year = {2009},
	month = {2009/9/8},
	abstract = {  We propose a new type of cooling mechanism for ultra-cold fermionic atom
ensembles, which capitalizes on the energy dependence of inelastic collisions
in the presence of a Feshbach resonance. We first discuss the case of a single
magnetic resonance, and find that the final temperature and the cooling rate is
limited by the width of the resonance. A concrete example, based on a p-wave
resonance of $^{40}$K, is given. We then improve upon this setup by using both
a very sharp optical or radio-frequency induced resonance and a very broad
magnetic resonance and show that one can improve upon temperatures reached with
current technologies.
},
	doi = {10.1103/PhysRevA.80.030702},
	url = {http://arxiv.org/abs/0903.2568v1},
	author = {L. Mathey and Eite Tiesinga and Paul S. Julienne and Charles W. Clark}
}
@article {1299,
	title = {Counterflow and paired superfluidity in one-dimensional Bose mixtures in  optical lattices
},
	journal = {Physical Review A},
	volume = {80},
	year = {2009},
	month = {2009/8/24},
	abstract = {  We study the quantum phases of mixtures of ultra-cold bosonic atoms held in
an optical lattice that confines motion or hopping to one spatial dimension.
The phases are found by using Tomonaga-Luttinger liquid theory as well as the
numerical method of time evolving block decimation (TEBD). We consider a binary
mixture with repulsive intra-species interactions, and either repulsive or
attractive inter-species interaction. For a homogeneous system, we find paired-
and counterflow-superfluid phases at different filling and hopping energies. We
also predict parameter regions in which these types of superfluid order coexist
with charge density wave order. We show that the Tomonaga-Luttinger liquid
theory and TEBD qualitatively agree on the location of the phase boundary to
superfluidity. We then describe how these phases are modified and can be
detected when an additional harmonic trap is present. In particular, we show
how experimentally measurable quantities, such as time-of-flight images and the
structure factor, can be used to distinguish the quantum phases. Finally, we
suggest applying a Feshbach ramp to detect the paired superfluid state, and a
$\pi/2$ pulse followed by Bragg spectroscopy to detect the counterflow
superfluid phase.
},
	doi = {10.1103/PhysRevA.80.023619},
	url = {http://arxiv.org/abs/0906.2150v1},
	author = {Anzi Hu and L. Mathey and Ippei Danshita and Eite Tiesinga and Carl J. Williams and Charles W. Clark}
}
