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We discuss various superfluid properties of a two-component Fermi system in the presence of a tight one-dimensional periodic potential in a three-dimensional system. We use a zero temperature mean field theory and derive analytical…

Other Condensed Matter · Physics 2009-01-16 Theja N. De Silva

We study the superfluid state of atomic Fermi gases using a BCS-BEC crossover theory. Our approach emphasizes non-condensed fermion pairs which strongly hybridize with their (Feshbach-induced) molecular boson counterparts. These pairs lead…

Soft Condensed Matter · Physics 2011-09-13 Jelena Stajic , J. N. Milstein , Qijin Chen , M. L. Chiofalo , M. J. Holland , K. Levin

At finite temperature, the hydrodynamic collective modes of superfluid trapped Fermi gases are coupled to the motion of the normal component, which in the BCS limit behaves like a collisionless normal Fermi gas. The coupling between the…

Other Condensed Matter · Physics 2008-11-26 M. Urban

In a recent article, Kwon et al. [Nature (London) {\bf 600}, 64 (2021)] revealed nonuniversal dissipative dynamics of quantum vortices in a fermionic superfluid. The enhancement of the dissipative process is pronounced for the…

Quantum Gases · Physics 2023-01-30 Andrea Barresi , Antoine Boulet , Piotr Magierski , Gabriel Wlazłowski

We discuss the superfluid phase transition of a strongly interacting Fermi gas with unequal (asymmetric) chemical potentials in two pairing hyperfine states, and map out its phase diagram near the BCS-BEC crossover. Our approach includes…

Statistical Mechanics · Physics 2007-05-23 Xia-Ji Liu , Hui Hu

We explore the zero temperature phase behavior of a two-dimensional two-component atomic Fermi gas with population and mass imbalance in the regime of the BEC-BCS crossover. Working in the mean-field approximation, we show that the normal…

Strongly Correlated Electrons · Physics 2009-01-16 G. J. Conduit , P. H. Conlon , B. D. Simons

We investigate the superfluid phase transition in a gas of Fermi atoms loaded on a three-dimensional optical lattice. When the lattice potential is strong, this system can be well described by an attractive Hubbard model. In this model, we…

Materials Science · Physics 2008-03-17 H. Tamaki , Y. Ohashi , K. Miyake

We show that two phenomena of superfluidity, superfluidity of weakly interacting bosons and superconductivity of the BCS model, are unified using the collective mode arising from the Berry connection for many-body wave functions. The…

Superconductivity · Physics 2020-01-22 Hiroyasu Koizumi

We have derived an exact expression for the total nondissipative transverse force acting on a quantized vortex moving in a uniform background. The derivation is valid for neutral boson or fermion superfluids, provided the order parameter is…

Condensed Matter · Physics 2009-01-23 D. J. Thouless , P. Ao , Q. Niu

We study quasiparticle dynamics in a Bose-Einstein condensate with a vortex by following the center of mass motion of a Bogoliubov wavepacket, and find important Berry phase effects due to the background flow. We show that Berry phase…

Statistical Mechanics · Physics 2009-11-11 Chuanwei Zhang , Artem M. Dudarev , Qian Niu

We analyze a superfluid state of two species gas of fermions trapped in a quasi-1D harmonic potential and interacting via attractive s-wave collisions. It is shown that the gap equation posesses a self consistent solution with an…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Jacek Dziarmaga , Krzysztof Sacha

Using numerical simulation based on a density-functional equation for a trapped Fermi super-fluid valid along the BCS-unitarity crossover, we establish robust scaling over many orders of magnitude in the observables of the system as a…

Quantum Gases · Physics 2015-05-13 Sadhan K. Adhikari

We establish a criterion for characterizing superfluidity in interacting, particle-number conserving systems of fermions as topologically trivial or non-trivial. Because our criterion is based on the concept of many-body fermionic parity…

Superconductivity · Physics 2016-09-26 Gerardo Ortiz , Emilio Cobanera

In this paper we address the ratio of the shear viscosity to entropy density $\eta/s$ in bosonic and fermionic superfluids. A small $\eta/s$ is associated with nearly perfect fluidity, and more general measures of the fluidity…

Quantum Gases · Physics 2015-06-22 Rufus Boyack , Hao Guo , K. Levin

We find a novel chiral superfluid (CSF) phase in a one-dimensional Bose-Fermi Hubbard model with significant mass and density imbalance between the two species. In the CSF phase, bosons condensate at non-zero momentum $\pm 2\pi /L$ with…

Quantum Gases · Physics 2025-02-13 Qi Song , Jie Lou , Yan Chen

We derive the phase diagram for ultracold trapped dipolar Fermi gases. Below the critical value of the dipole-dipole interaction energy, the BCS transition into a superfluid phase ceases to exist. The critical dipole strength is obtained as…

Condensed Matter · Physics 2009-11-10 M. A. Baranov , L. Dobrek , M. Lewenstein

Motivated by recent experimental advances in ultracold atoms, we analyze a non-Hermitian (NH) BCS Hamiltonian with a complex-valued interaction arising from inelastic scattering between fermions. We develop a mean-field theory to obtain a…

We discuss correlations between particles of different momentum in a superfluid fermi gas, accessible through noise measurements of absorption images of the expanded gas. We include two elements missing from the simplest treatment, based on…

Statistical Mechanics · Physics 2009-11-11 Austen Lamacraft

The superfluid fraction $f$ of a quantum fluid is defined in terms of the response of the system to a weak and constant drag. Notably, Leggett long ago derived two simple expressions providing a rigorous upper bound and a heuristic lower…

Quantum Gases · Physics 2025-01-16 Daniel Pérez-Cruz , Grigori E. Astrakharchik , Pietro Massignan

We present a theory for a superfluid Fermi gas near the BCS-BEC crossover, including pairing fluctuation contributions to the free energy similar to that considered by Nozieres and Schmitt-Rink for the normal phase. In the strong coupling…

Superconductivity · Physics 2007-05-23 Hui Hu , Xia-Ji Liu , Peter D. Drummond