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Related papers: BCS-BEC crossover in a random external potential

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We review the BCS-BEC crossover in relativistic Fermi systems, including the QCD matter at finite density. In the first part we study the BCS-BEC crossover in a relativistic four-fermion interaction model and show how the relativistic…

Quantum Gases · Physics 2017-02-17 Lianyi He , Shijun Mao , Pengfei Zhuang

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 investigate the crossover from the Bardeen-Cooper-Schrieffer (BCS) state of weakly-bound Cooper pairs to the Bose-Einstein Condensate (BEC) of strongly-bound molecular dimers in a gas of ultracold atoms loaded on a two-dimensional…

Quantum Gases · Physics 2012-08-21 Luca Salasnich , Flavio Toigo

We derive the criterion for the Bose-Einstein condensation (BEC) of a Gaussian field $\phi$ (real or complex) in the thermodynamic limit. The field is characterized by its covariance function and the control parameter is the intensity…

Statistical Mechanics · Physics 2015-06-03 Philippe Mounaix , Satya N. Majumdar , Abhimanyu Banerjee

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 study the finite temperature $T$ behavior of trapped Fermi gases as they undergo BCS-Bose Einstein condensation (BEC) crossover, in the presence of a population imbalance. Our results, in qualitative agreement with recent experiments,…

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

We investigate the properties of a three-dimensional homogeneous dipolar Bose gas in a weak random potential with a Gaussian correlation function at finite temperature. Using the Bogoliubov theory (beyond the mean field), we calculate the…

Disordered Systems and Neural Networks · Physics 2015-08-26 Abdelaali Boudjemaa

We study multiple period states of a two-component unpolarized superfluid Fermi gas in an optical lattice along the Bardeen-Cooper-Schrieffer (BCS) to Bose-Einstein condensate (BEC) crossover. The existence of states whose period is a…

Quantum Gases · Physics 2016-02-02 Sukjin Yoon , Franco Dalfovo , Takashi Nakatsukasa , Gentaro Watanabe

We reinvestigate the Bose-Einstein condensation (BEC) thermodynamics of a weakly interacting dilute Bose gas under the action of a trap using a semiclassical two-fluid mean-field model in order to find the domain of applicability of the…

Soft Condensed Matter · Physics 2009-10-31 Sadhan K. Adhikari , A. Gammal

The condensation of fermion pairs lies at the heart of superfluidity. However, for strongly correlated systems with reduced dimensionality the mechanisms of pairing and condensation are still not fully understood. In our experiment we use…

Quantum Gases · Physics 2015-06-11 M. G. Ries , A. N. Wenz , G. Zürn , L. Bayha , I. Boettcher , D. Kedar , P. A. Murthy , M. Neidig , T. Lompe , S. Jochim

Atomic Fermi gases have been an ideal platform for simulating conventional and engineering exotic physical systems owing to their multiple tunable control parameters. Here we investigate the effects of mixed dimensionality on the superfluid…

Quantum Gases · Physics 2017-10-12 Leifeng Zhang , Yanming Che , Jibiao Wang , Qijin Chen

We use the variational cluster approximation to study the superconducting ground state in the two-dimensional attractive Hubbard model, putting particular emphasis on the significance of quantum fluctuations of the system. We first show…

Strongly Correlated Electrons · Physics 2014-01-22 Tatsuya Kaneko , Yukinori Ohta

A realistic description of the Josephson effect at finite temperature with ultra-cold Fermi gases embedded in nontrivial geometrical constraints (typically, a trap plus a barrier) requires appropriate consideration of pairing fluctuations…

Superconductivity · Physics 2024-03-25 Verdiana Piselli , Leonardo Pisani , Giancarlo Calvanese Strinati

We consider a two-component gas of fermionic atoms confined to a quasi-two-dimensional (quasi-2D) geometry by a harmonic trapping potential in the transverse direction. We construct a mean field theory of the BCS-BEC crossover at zero…

Quantum Gases · Physics 2014-03-04 Andrea M. Fischer , Meera M. Parish

In this paper we discuss Bose-Einstein condensation (BEC) in systems of pairwise non-interacting bosons in random potentials in $d$ dimensions. Working in a rather general framework, we provide a "gap condition" which is sufficient to…

Mathematical Physics · Physics 2020-07-20 Joachim Kerner , Maximilian Pechmann , Wolfgang Spitzer

We determine the effects on the BCS-BEC crossover of the energy dependence of the effective two-body interaction, which at low energies is determined by the effective range. To describe interactions with an effective range of either sign,…

Superconductivity · Physics 2008-11-26 L. M. Jensen , H. M. Nilsen , Gentaro Watanabe

Preparation of molecular quantum gas promises novel applications including quantum control of chemical reactions, precision measurements, quantum simulation and quantum information processing. Experimental preparation of colder and denser…

Atomic Physics · Physics 2021-04-29 Zhendong Zhang , Liangchao Chen , Kaixuan Yao , Cheng Chin

We describe the effects of disorder on the critical temperature of s-wave superfluids from the BCS to the BEC regime, with direct application to ultracold Fermi atoms. In the BCS regime the pair breaking and phase coherence temperature…

Quantum Gases · Physics 2009-04-28 Li Han , Carlos A. R. Sa de Melo

We investigate a Bose-Einstein condensate trapped in a 2D optical lattice in the presence of weak disorder within the framework of the Bogoliubov theory. In particular, we analyze the combined effects of disorder and an optical lattice on…

Quantum Gases · Physics 2015-05-14 Ying Hu , Zhaoxin Liang , Bambi Hu

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