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Related papers: The BCS gap equation for spin-polarized fermions

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We investigate the BCS critical temperature $T_c$ in the high-density limit and derive an asymptotic formula, which strongly depends on the behavior of the interaction potential $V$ on the Fermi-surface. Our results include a rigorous…

Mathematical Physics · Physics 2023-12-21 Joscha Henheik

We study the concavity of the dispersion relation $q\mapsto \omega\_{\mathbf{q}}$ of the bosonic excitations of a three-dimensional spin-$1/2$ Fermi gas in the Random Phase Approximation (RPA). In the limit of small wave numbers $q$ we…

Quantum Gases · Physics 2016-02-03 H Kurkjian , Yvan Castin , A Sinatra

Assuming the validity of grand canonical statistics, we study the properties of a spin-polarized Fermi gas in harmonic traps. Universal forms of Fermi temperature $T_F$, internal energy $U$ and the specific heat per particle of the trapped…

Quantum Physics · Physics 2009-11-06 X. X. Yi , J. C. Su

The unitarity regime of the BCS-BEC crossover can be realized by diluting a system of two-component lattice fermions with an on-site attractive interaction. We perform a systematic-error-free finite-temperature simulations of this system by…

Statistical Mechanics · Physics 2007-05-23 Evgeni Burovski , Nikolay Prokof'ev , Boris Svistunov , Matthias Troyer

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 consider the low density limit of a Fermi gas in the BCS approximation. We show that if the interaction potential allows for a two-particle bound state, the system at zero temperature is well approximated by the Gross-Pitaevskii…

Mathematical Physics · Physics 2015-05-28 Christian Hainzl , Robert Seiringer

We propose a statistical mechanical framework to unify the observed relationship between the superconducting energy gap $\Delta$, the pseudogap $\Delta^\ast$, and the critical temperature $T_\mathrm{c}$. In this model, fermions couple as a…

Superconductivity · Physics 2025-04-15 Chung-Ru Lee

The superfluid phase diagrams of a two-dimensional cold polarized Fermi gas in the BCS-BEC crossover are systematically and analytically investigated. In the BCS-Leggett mean field theory, the transition from unpolarized superfluid phase to…

Superconductivity · Physics 2016-09-08 Lianyi He , Pengfei Zhuang

We review the study of the superfluid phase transition in a system of fermions whose interaction can be tuned continuously along the crossover from Bardeen-Cooper-Schrieffer (BCS) superconducting phase to a Bose-Einstein condensate (BEC),…

Quantum Gases · Physics 2021-05-06 Luca Dell'Anna , Stefano Grava

The recent experimental realization of spin-orbit coupling for ultra-cold atoms has generated much interest in the physics of spin-orbit coupled degenerate Fermi gases. Although recently the BCS-BEC crossover in three-dimensional (3D)…

Quantum Gases · Physics 2012-01-05 Gang Chen , Ming Gong , Chuanwei Zhang

Using a formalism based on the two-body S-matrix we study two-dimensional Bose and Fermi gases with both attractive and repulsive interactions. Approximate analytic expressions, valid at weak coupling and beyond, are developed and applied…

Quantum Gases · Physics 2017-07-18 Guilherme Franca , Andre LeClair , Joshua Squires

We calculate the mean-field thermodynamics of a spherically trapped Fermi gas with unequal spin populations in the unitarity limit, comparing results from the Bogoliubov-de Gennes equations and the local density approximation. We follow the…

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

We investigate a mix-dimensional Fermi-Fermi mixture in which one species is confined in two-dimensional(2D) space while the other is free in three-dimensional space(3D). We determine the superfluid transition temperature $T_{c}$ for the…

Superconductivity · Physics 2015-05-27 Xiaosen Yang , Beibing Huang , Shaolong Wan

Exploiting the similarity between the bunched single-particle energy levels of nuclei and of random distributions around the Fermi surface, pairing properties of the latter are calculated to establish statistically-based bounds on the basic…

Nuclear Theory · Physics 2018-07-04 A. A. Mamun , C. Constantinou , M. Prakash

It was recently shown that the BCS formalism leads to several solutions for the energy gap and the equilibrium quasiparticle distribution, with a phase transition temperature which depends on the position of the chemical potential within…

Superconductivity · Physics 2019-08-19 Dragos-Victor Anghel

A gas of ultracold $^6$Li atoms (effective spin 1/2) confined to an elongated trap with one-dimensional properties is a candidate to display three different phases: (i) fermions bound in Cooper-pair-like states, (ii) unbound spin-polarized…

Quantum Gases · Physics 2015-05-28 Pedro Schlottmann , Andrei Zvyagin

We analyze strongly interacting Fermi gases in the unitary regime by considering the generalization to an arbitrary number N of spin-1/2 fermion flavors with Sp(2N) symmetry. For N=\infty this problem is exactly solved by the BCS-BEC…

Other Condensed Matter · Physics 2009-02-05 M. Y. Veillette , D. E. Sheehy , L. Radzihovsky

We develop an explicit description of a time-dependent response of fermionic condensates to perturbations. The dynamics of Cooper pairs at times shorter than the energy relaxation time can be described by the BCS model. We obtain a general…

Superconductivity · Physics 2009-11-10 Emil A. Yuzbashyan , Boris L. Altshuler , Vadim B. Kuznetsov , Victor Z. Enolskii

A major impediment to solving the problem of high-$T_c$ superconductivity is the ongoing confusion about the magnitude, structure and doping dependence of the superconducting gap, $\Delta_0$, and of the mysterious pseudogap found in…

Superconductivity · Physics 2009-09-01 J. L. Tallon , J. G. Storey

We theoretically investigate magnetic properties of a unitary Fermi gas in a harmonic trap. Including strong pairing fluctuations within the framework of an extended $T$-matrix approximation (ETMA), as well as effects of a trap potential…

Quantum Gases · Physics 2016-01-27 Hiroyuki Tajima , Ryo Hanai , Yoji Ohashi