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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

In this article we have investigated the effect of weak random disorder in the BCS-BEC crossover region. The disorder is included in the mean field formalism through NSR theory of superconducting fluctuations. A self consistent numerical…

Quantum Gases · Physics 2012-06-11 Ayan Khan , Saurabh Basu , Sang Wook Kim

The possibility of the crossover from the BCS pairing to the Bose-Einstein condensate (BEC) of diquarks with going down in density is discussed in the framework of in the Nambu Jona-Lasinio (NJL) model. We find that the quark matter at…

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

Several novel multi-component fermionic condensates show universal behavior under imbalance in the number of fermionic species. Here I discuss their phase structure, thermodynamics, and the transition from the weak (BCS) to strong (BEC)…

Nuclear Theory · Physics 2011-09-23 Armen Sedrakian

We present a numerical study of the one-dimensional BCS-BEC crossover of a spin-imbalanced Fermi gas. The crossover is described by the Bose-Fermi resonance model in a real space representation. Our main interest is in the behavior of the…

Quantum Gases · Physics 2013-05-29 F. Heidrich-Meisner , A. E. Feiguin , U. Schollwoeck , W. Zwerger

We study finite-temperature properties of a two-dimensional superfluid made of ultracold alkali-metal atoms in the BCS-BEC crossover. We investigate the region below the critical temperature $T_{BKT}$ of the Berezinskii-Kosterlitz-Thouless…

Quantum Gases · Physics 2013-11-20 L. Salasnich , P. A. Marchetti , F. Toigo

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

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

The BCS-to-BEC crossover, as well as the nature of Cooper pairs, in a superconducting and Fermi superfluid medium is studied from the exact ground state wavefunction of the reduced BCS Hamiltonian. As the strength of the interaction…

Superconductivity · Physics 2009-11-11 Gerardo Ortiz , Jorge Dukelsky

We demonstrate the existence of supersonic bell soliton in the Bardeen-Cooper-Schrieffer-Bose-Einstein condensate (BCS-BEC) crossover regime. Starting from the extended Thomas-Fermi density functional theory of superfluid order parameter, a…

Quantum Gases · Physics 2013-05-13 Ayan Khan , Prasanta K Panigrahi

The strongly-correlated regime of the BCS-BEC crossover can be realized by diluting a system of two-component fermions with a short-range attractive interaction. We investigate this system via a novel continuous-space-time diagrammatic…

Strongly Correlated Electrons · Physics 2009-11-13 Evgeni Burovski , Evgeny Kozik , Nikolay Prokof'ev , Boris Svistunov , Matthias Troyer

We provide an analytic solution for the mean-field equations and for the relevant physical quantities at the Gaussian level, in terms of the complete elliptic integrals of the first and second kinds, for the crossover problem from BCS…

Superconductivity · Physics 2009-10-30 M. Marini , F. Pistolesi , G. C. Strinati

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

The superfluid phases in the resonant dipolar Fermi gases are investigated by the standard mean-field theory. In contrast to the crossover from Bose-Einstein condensation (BEC) to Bardeen-Cooper-Schrieffer (BCS) superfluid in the Fermi…

Quantum Gases · Physics 2013-05-30 T. Shi , S. -H. Zou , H. Hu , C. -P. Sun , S. Yi

We consider the problem of the crossover from BCS superconductivity to Bose-Einstein condensation in three dimensions for a system of fermions with an attractive interaction, for which we adopt the simplifying assumption of a suitably…

Superconductivity · Physics 2009-10-31 P. Pieri , G. C. Strinati

We explore a BCS Bose Einstein crossover scenario for $0 \leq T \leq T_c$ and its implications for the superfluid density and specific heat. The low lying excitations consist of nodal (fermionic) quasi-particles as well as excited (bosonic)…

Superconductivity · Physics 2007-05-23 Qijin Chen , Ioan Kosztin , K. Levin

Phase transitions are ubiquitous in our three-dimensional world. By contrast most conventional transitions do not occur in infinite uniform two-dimensional systems because of the increased role of thermal fluctuations. Here we explore the…

We discuss several possible experimental signatures of the Bose-Einstein condensation (BEC) transition for an ultracold Bose gas in an inhomogeneous optical lattice. Based on the commonly used time-of-flight imaging technique, we show that…

Superconductivity · Physics 2008-05-21 G. -D. Lin , Wei Zhang , L. -M. Duan

The crossover between low and high density regimes of exciton-polariton condensates is examined using a BCS wavefunction approach. Our approach is an extension of the BEC-BCS crossover theory for excitons, but includes a cavity photon…

Quantum Gases · Physics 2010-10-28 Tim Byrnes , Tomoyuki Horikiri , Natsuko Ishida , Yoshihisa Yamamoto

We study the behaviour of ultracold bosonic gas in the critical region above the Bose-Einstein condensation in the presence of an artificial magnetic field, $B_\mathrm{art}$. We show that the condensate fluctuations above the critical…

Quantum Gases · Physics 2016-06-01 Arvid J. Kingl , D. M. Gangardt , Igor V. Lerner