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

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By using a well established 'ab initio' theoretical approach developed in the past to quantitatively study the superconductivity of condensed matter systems, which is based on the Kohn-Sham Density Functional theory, I study the superfluid…

Quantum Gases · Physics 2016-06-01 Francesco Ancilotto

Bose-Einstein condensation (BEC) in two dimensions (2D) (e.g., to describe the quasi-2D cuprates) is suggested as the possible mechanism widely believed to underlie superconductivity in general. A crucial role is played by nonzero…

Superconductivity · Physics 2016-08-15 S. K. Adhikari , M. Casas , A. Puente , A. Rigo , M. Fortes , M. A. Solís , M. de Llano , A. A. Valladares , O. Rojo

We present a theory of superconducting p-n junctions. We consider a 2-band model of doped bulk semiconductors with attractive interactions between the charge carriers and derive the superconducting order parameter, the quasiparticle density…

Superconductivity · Physics 2020-03-25 A. Niroula , G. Rai , S. Haas , S. Kettemann

The subject of BCS - Bose Einstein condensation (BEC) crossover is particularly exciting because of its realization in ultracold Fermi gases and its possible relevance to high temperature superconductors. In the paper we review that body of…

Other Condensed Matter · Physics 2015-05-13 K. Levin , Qijin Chen , Chih-Chun Chien , Yan He

We study a gas of fermions undergoing a wide resonance s-wave BCS-BEC crossover, in the BEC regime at zero temperature. We calculate the chemical potential and the speed of sound of this Bose-condensed gas, as well as the condensate…

Superconductivity · Physics 2009-11-11 J. Levinsen , V. Gurarie

We use the functional integral approach to study low energy collective excitations in a continuum model of neutral two-band superfluids at T=0 for all couplings with a separable pairing interaction. In the long wavelength and low frequency…

Superconductivity · Physics 2009-11-10 M. Iskin , C. A. R. Sa de Melo

This paper gives a survey of a diagrammatic approach for fermionic pairing fluctuations, which are relevant to the BCS-BEC crossover realized with ultracold Fermi gases. Emphasis will be given to the physical intuition about the relevant…

Quantum Gases · Physics 2010-11-29 G. C. Strinati

In this work, we present a theoretical study for the collective oscillation modes, i.e. quadrupole, radial and axial mode, of a mixture of Bose and Fermi superfluids in the crossover from a Bardeen-Cooper-Schrieffer (BCS) superfluid to a…

Quantum Gases · Physics 2019-10-03 Wen Wen , Ying Wang , Jianyong Wang

We examine key aspects of the theory of the Bardeen-Cooper-Schrieffer (BCS) to Bose-Einstein condensation (BEC) crossover, focusing on the temperature dependence of the chemical potential, $\mu$. We identify an accurate method of…

Superconductivity · Physics 2023-10-16 John Sous , Yu He , Steven A. Kivelson

The pairing and superfluid phenomena in a two-component Fermi gas can be strongly affected by the population and mass imbalances. Here we present phase diagrams of atomic Fermi gases as they undergo BCS--Bose-Einstein condensation (BEC)…

Quantum Gases · Physics 2014-04-24 Jibiao Wang , Hao Guo , Qijin Chen

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

Experiments with ultracold atoms provide a highly controllable laboratory setting with many unique opportunities for precision exploration of quantum many-body phenomena. The nature of such systems, with strong interaction and quantum…

Quantum Gases · Physics 2017-12-13 Ettore Vitali , Hao Shi , Mingpu Qin , Shiwei Zhang

We examine collective modes, stability, and BCS pairing in a quasi-two-dimensional gas of dipolar fermions aligned by an external field. By using the (conserving) Hartree-Fock approximation, which treats direct and exchange interactions on…

Quantum Gases · Physics 2011-12-26 L. M. Sieberer , M. A. Baranov

We investigate the ground-state properties of ultracold two-component Fermi gases in the presence of a transverse harmonic potential, focusing on the strongly interacting regime in which pairs of fermions form tightly bound molecules. Using…

Quantum Gases · Physics 2025-12-11 Giovanni Midei , Jordi Boronat , Grigory E. Astrakharchik

We investigate the ground state of interacting spin-$\half$ fermions (3D) at a finite density ($\rho \sim \kf^3$) in the presence of a uniform non-Abelian gauge field. The gauge field configuration (GFC) described by a vector $\blam \equiv…

Quantum Gases · Physics 2011-07-27 Jayantha P. Vyasanakere , Shizhong Zhang , Vijay B. Shenoy

The functional renormalisation group is used for the BCS-BEC crossover in gases of ultracold fermionic atoms. In a simple truncation, we see how universality and an effective theory with composite bosonic di-atom states emerge. We obtain a…

Superconductivity · Physics 2009-11-13 S. Diehl , H. Gies , J. M. Pawlowski , C. Wetterich

We use the functional renormalization group approach with partial bosonization in the particle-particle channel to study the effect of order parameter fluctuations on the BCS-BEC crossover of superfluid fermions in three dimensions. Our…

Quantum Gases · Physics 2009-09-29 Lorenz Bartosch , Peter Kopietz , Alvaro Ferraz

We analyze the evolution of two-band superfluidity from the weak coupling Bardeen-Cooper-Schrieffer (BCS) to the strong coupling Bose-Einstein condensation (BEC) limit. When the interband interaction is tuned from negative to positive…

Superconductivity · Physics 2009-11-11 M. Iskin , C. A. R. Sá de Melo

We study the evolution of dynamic properties of the BCS/BEC (Bose-Einstein Condensate) crossover in a relativistic superfluid as well as its thermodynamics. We put particular focus on the change in the soft mode dynamics throughout the…

High Energy Physics - Phenomenology · Physics 2008-11-26 H. Abuki

We review efforts to unify both the Bardeen, Cooper and Schrieffer (BCS) and Bose-Einstein condensation (BEC) pictures of superconductivity. We have finally achieved this in terms of a "\textit{complete} boson-fermion (BF) model" (CBFM)…

Superconductivity · Physics 2007-05-23 J. Batle , M. Casas , M. Fortes , M. de Llano , O. Rojo , F. J. Sevilla , M. A. Solis , V. V. Tolmachev