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Related papers: BCS-BEC crossover in a quasi-two-dimensional Fermi…

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We present a theoretical study of the ground state of the BCS-BEC crossover in dilute two-dimensional Fermi gases. While the mean-field theory provides a simple and analytical equation of state, the pressure is equal to that of a…

Quantum Gases · Physics 2015-08-17 Lianyi He , Haifeng Lv , Gaoqing Cao , Hui Hu , Xia-Ji Liu

Quantum-size oscillations of the basic physical characteristics of a confined fermionic condensate are a well-known phenomenon. Its conventional understanding is based on the single-particle physics, whereby the oscillations follow the…

Quantum Gases · Physics 2012-09-17 A. A. Shanenko , M. D. Croitoru , A. V. Vagov , V. M. Axt , A. Perali , F. M. Peeters

This paper addresses the transition from the normal to the superfluid state in strongly correlated two dimensional fermionic superconductors and Fermi gases. We arrive at the Berezinskii-Kosterlitz-Thouless (BKT) temperature…

Superconductivity · Physics 2020-07-13 Xiaoyu Wang , Qijin Chen , K. Levin

We study the effects of an external periodic potential on the critical velocity of a superfluid Fermi gas in the crossover between the Bardeen-Cooper-Schrieffer (BCS) phase and Bose-Einstein condensation (BEC). We numerically solve the…

Quantum Gases · Physics 2011-08-04 Gentaro Watanabe , Franco Dalfovo , Lev P. Pitaevskii , Sandro Stringari

We investigate the specific heat at constant volume $C_V$ in the BCS (Bardeen-Cooper-Schrieffer)-BEC (Bose-Einstein condensation) crossover regime of an ultracold Fermi gas above the superfluid phase transition temperature $T_{\rm c}$.…

Quantum Gases · Physics 2016-02-03 Pieter van Wyk , Hiroyuki Tajima , Ryo Hanai , Yoji Ohashi

The pairing of fermionic atoms in a mixture of atomic fermion and boson gases at zero temperature is investigated. The attractive interaction between fermions, that can be induced by density fluctuations of the bosonic background, can give…

Quantum Gases · Physics 2015-05-30 F. Matera , A. Dellafiore

Strong evidence for pairing and superfluidity has recently been found in atomic Fermi gases at the BCS-BEC crossover both in collective modes and RF excitation energies. It is argued that the scale for the effective pairing gaps measured in…

Superconductivity · Physics 2009-11-10 H. Heiselberg

We theoretically investigate the Bardeen-Cooper-Schrieffer (BCS) to Bose-Einstein condensation (BEC) crossover in a two-dimensional Fermi gas with the finite-range interaction by using the Hartree-Fock-Bogoliubov theory. Expanding the…

Quantum Gases · Physics 2024-03-20 Hikaru Sakakibara , Hiroyuki Tajima , Haozhao Liang

We investigate strong coupling effects on the superfluid phase transition in a gas of Fermi atoms with a Feshbach resonance. The Feshbach resonance describes a composite quasi-Boson, which can give rise to an additional pairing interaction…

Soft Condensed Matter · Physics 2016-08-31 Y. Ohashi , A. Griffin

We investigate the dimensional crossover from three to two dimensions in an ultracold Fermi gas across the whole BCS-BEC crossover. Of particular interest is the strongly interacting regime as strong correlations are more pronounced in…

Quantum Gases · Physics 2021-03-23 Bruno M. Faigle-Cedzich , Jan M. Pawlowski , Christof Wetterich

The ground-state superfluid behavior of ultracold atomic Fermi gases with a short-range attractive interaction in a quasi-two-dimensional Lieb lattice is studied using BCS mean-field theory, within the context of BCS-BEC crossover. We find…

Quantum Gases · Physics 2024-03-27 Hao Deng , Chuping Li , Yuxuan Wu , Lin Sun , Qijin Chen

We elucidate the role of the effective range in the Bose-Einstein-condensate (BEC) to Bardeen-Cooper-Schrieffer (BCS) crossover regime of two-component fermions in three dimensions. In contrast to ultracold Fermi gases near the broad…

Quantum Gases · Physics 2023-05-01 Hiroyuki Tajima , Haozhao Liang

We study resonantly-paired s-wave superfluidity in a degenerate gas of two species (hyperfine states labeled by $\uparrow,\downarrow$) of fermionic atoms when the numbers $N_{\uparrow}$ and $N_{\downarrow}$ of the two species are {\it…

Superconductivity · Physics 2009-11-11 Daniel E. Sheehy , Leo Radzihovsky

In a trapped atomic Fermi gas, one can tune continuously via a Feshbach resonance the effective pairing interaction between fermionic atoms from very weak to very strong. As a consequence, the low temperature superfluidity evolves…

Quantum Gases · Physics 2011-01-17 Yi Yu , Qijin Chen

We introduce a quasi-analytic nonlinear Schr\"odinger equation with beyond mean-field corrections to describe the dynamics of a zero-temperature dilute superfluid Fermi gas in the crossover from the weak-coupling Bardeen-Cooper-Schrieffer…

Other Condensed Matter · Physics 2009-11-13 S. K. Adhikari

Very recently quasi two-dimensional (2D) systems made of attractive fermionic alkali-metal atoms with a widely tunable interaction due to Fano-Feshbach resonances have been realized. In this way it has been achieved the 2D crossover from…

Quantum Gases · Physics 2016-12-13 L. Salasnich , G. Bighin

We investigate Bardeen-Cooper-Schrieffer (BCS)- Bose-Einstein condensation (BEC) crossover in a two-band superfluid Fermi gas with an energy shift between the bands. When the intraband coupling in the cold (first) band is fixed as weak, we…

Superconductivity · Physics 2019-10-09 Yuriy Yerin , Hiroyuki Tajima , Pierbiagio Pieri , Andrea Perali

We discuss an integrable model of interacting Fermions in one dimension, that allows an exact description of the crossover from a BCS- to a Bose-like superfluid. This model bridges the Gaudin-Yang model of attractive spin 1/2 Fermions to…

Statistical Mechanics · Physics 2007-05-23 J. N. Fuchs , A. Recati , W. Zwerger

We investigate the ground state properties of a disordered superfluid Fermi gas across the BCS-BEC (Bose Einstein condensate) crossover. We show that, for weak disorder, both the depletion of the condensate fraction of pairs and the normal…

Superconductivity · Physics 2009-11-13 G. Orso

We present a pairing fluctuation theory which self-consistently incorporates finite momentum pair excitations in the context of BCS--Bose-Einstein condensation (BEC) crossover, and we apply this theory to high $T_c$ superconductors and…

Strongly Correlated Electrons · Physics 2011-09-13 Qijin Chen , Chih-Chun Chien , Yan He , K. Levin