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Related papers: Cooper pairing and BCS-BEC evolution in mixed-dime…

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We review our studies on Bose and Fermi superfluids of cold atomic gases in optical lattices at zero temperature. Especially, we focus on superfluid Fermi gases along the crossover between the Bardeen-Cooper-Schrieffer (BCS) and the…

Quantum Gases · Physics 2013-10-02 Gentaro Watanabe , Sukjin Yoon

The superfluid transition in an ultracold two-component atomic Fermi gas is analyzed in the case where the two components have different densities. We describe a superfluid state which spontaneously breaks the rotational-symmetry by…

Superconductivity · Physics 2007-05-23 Armen Sedrakian , Jordi Mur-Petit , Artur Polls , Herbert Müther

We investigate the finite-temperature superfluid behavior of ultracold atomic Fermi gases in quasi-two-dimensional Lieb lattices with a short-range attractive interaction, using a pairing fluctuation theory within the BCS-BEC crossover…

Quantum Gases · Physics 2024-01-09 Hao Deng , Lin Sun , Chuping Li , Yuxuan Wu , Junru Wu , Qijin Chen

The BCS-BEC crossover realized experimentally with ultra-cold Fermi gases may be considered as one of the important scientific achievements occurred during the last several years. The flexibility for operating on these systems on the…

Quantum Gases · Physics 2024-03-20 Giancarlo Calvanese Strinati

Anisotropic pairing between fermion species with different fermi momenta opens two-dimensional areas of gapless excitations, thus producing a spatially homogeneous state with coexisting superfluid and normal fluids. This breached pairing…

Superconductivity · Physics 2007-05-23 E. Gubankova , E. G. Mishchenko , F. Wilczek

We show that atomic Fermi gases in quasi2D geometries are promising for achieving superfluidity. In the regime of BCS pairing for weak attraction, we calculate the critical temperature T_c and analyze possibilities of increasing the ratio…

Statistical Mechanics · Physics 2009-11-07 D. S. Petrov , M. A. Baranov , G. V. Shlyapnikov

We develop a pairing-field formalism for ab initio studies of non-relativistic two-component fermions on a $(d\!+\!1)$-dimensional spacetime lattice. More specifically, we focus on theories where the interaction between the two components…

Quantum Gases · Physics 2024-04-03 Florian Ehmann , Joaquín E. Drut , Jens Braun

The crossover from weak coupling Bardeen-Cooper-Schrieffer (BCS) pairing to a Bose-Einstein condensate (BEC) of tightly bound pairs, as a function of the attractive interaction in Fermi systems, has long been of interest to theoretical…

Quantum Gases · Physics 2014-04-09 Mohit Randeria , Edward Taylor

We study s-wave superconductivity in the two dimensional attractive Hubbard model in an applied magnetic field, assume the extreme Pauli limit, and examine the role of spatial fluctuations in the coupling regime corresponding to BCS-BEC…

Quantum Gases · Physics 2016-05-26 Madhuparna Karmakar , Pinaki Majumdar

We study the BCS-Bose Einstein Condensation (BEC) crossover of a three dimensional spin polarized Fermi gas with Rashba spin-orbital-coupling (SOC). At finite temperature, the effects of non-condensed pairs due to the thermal excitation are…

Quantum Gases · Physics 2016-06-24 Chang-Yan Wang , Yan He

We investigate the BCS-BEC crossover in three dimensional degenerate Fermi gases in the presence of spin-orbit coupling (SOC) and Zeeman field. We show that the superfluid order parameter destroyed by a large Zeeman field can be restored by…

Quantum Gases · Physics 2011-11-08 Ming Gong , Sumanta Tewari , Chuanwei Zhang

Fermi gas with time-dependent pairing interaction hosts several different dynamical states. Coupling between the collective BCS pairing mode and individual Cooper pair states can make the latter either synchronize or dephase. We describe…

Mesoscale and Nanoscale Physics · Physics 2008-04-12 R. A. Barankov , L. S. Levitov

We investigate single-particle properties of a mass-imbalanced Fermi gas in the BCS (Bardeen-Cooper-Schrieffer)-BEC (Bose-Einstein condensation) crossover region. In the presence of mass imbalance, we point out that the ordinary $T$-matrix…

Quantum Gases · Physics 2013-11-20 Ryo Hanai , Takashi Kashimura , Ryota Watanabe , Daisuke Inotani , Yoji Ohashi

We consider a mixture of spin-1/2 bosons and fermions, where only the bosons are subjected to the spin-orbit coupling induced by Raman beams. The fermions, although not directly coupled to the Raman lasers, acquire an effective spin-orbit…

Atomic Physics · Physics 2019-09-25 Chuanzhou Zhu , Li Chen , Hui Hu , Xia-Ji Liu , Han Pu

Wave-vector resolved radio frequency (rf) spectroscopy data for an ultracold trapped Fermi gas are reported for several couplings at Tc, and extensively analyzed in terms of a pairing-fluctuation theory. We map the evolution of a strongly…

Having both elastic and inelastic two-body processes that are characterized by a complex $s$-wave scattering length between $\uparrow$ and $\downarrow$ fermions in mind, here we apply the non-Hermitian extension of the mean-field theory to…

Quantum Gases · Physics 2021-01-26 M. Iskin

We show the emergence of a strongly interacting Bose-Fermi mixture from a two-component Fermi mixture with population imbalance. By analyzing in situ density profiles of $^6$Li atoms in the BCS-BEC crossover regime we identify a critical…

Statistical Mechanics · Physics 2009-11-13 Yong-il Shin , André Schirotzek , Christian H. Schunck , Wolfgang Ketterle

We show that a two-dimensional (2D) spin-polarised Fermi gas immersed in a 3D Bose-Einstein condensate (BEC) constitutes a very promising system to realise a $p_x+ip_y$ superfluid. The fermions attract each other via an induced interaction…

Quantum Gases · Physics 2016-12-14 Zhigang Wu , Georg M. Bruun

In this letter we show that the vortex lattice structure in the Bose-Fermi superfluid mixture can undergo a sequence of structure transitions when the Fermi superfluid is tuned from the BCS regime to the BEC regime. This is due to different…

Quantum Gases · Physics 2017-03-01 Yuzhu Jiang , Ran Qi , Zhe-Yu Shi , Hui Zhai

We consider pairing in a two-component atomic Fermi gas, in a three-dimensional optical lattice, when the components have unequal densities, i.e. the gas is polarized. We show that a superfluid where the translational symmetry is broken by…

Superconductivity · Physics 2007-05-23 T. Koponen , J. Kinnunen , J. -P. Martikainen , L. M. Jensen , P. Torma