English
Related papers

Related papers: The induced interaction in a Fermi gas with a BEC-…

200 papers

We study the mass imbalanced Fermi-Fermi mixture within the framework of a two-dimensional lattice fermion model. Based on the thermodynamic and species dependent quasiparticle behavior we map out the finite temperature phase diagram of…

Strongly Correlated Electrons · Physics 2018-03-28 Madhuparna Karmakar

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

We investigate strong-coupling effects on normal state properties of an ultracold Fermi gas. Within the framework of $T$-matrix approximation in terms of pairing fluctuations, we calculate the single-particle density of states (DOS), as…

Quantum Gases · Physics 2013-05-29 Shunji Tsuchiya , Ryota Watanabe , Yoji Ohashi

We investigate pseudogap phenomena originating from pairing fluctuations in the BCS-BEC crossover regime of a two-dimensional Fermi gas in a harmonic trap. Including pairing fluctuations within a $T$-matrix theory and effects of a trap…

Quantum Gases · Physics 2015-06-05 Ryota Watanabe , Shunji Tsuchiya , Yoji Ohashi

We investigate single-particle excitations and strong-coupling effects in the BCS-BEC crossover regime of a superfluid Fermi gas. Including phase and amplitude fluctuations of the superfluid order parameter within a $T$-matrix theory, we…

Quantum Gases · Physics 2015-05-19 Ryota Watanabe , Shunji Tsuchiya , Yoji Ohashi

We argue that, for the recent experiments with imbalanced fermion gases, a temperature difference may occur between the normal (N) and the gapped superfluid (SF) phase. Using the mean-field formalism, we study particle scattering off the…

Other Condensed Matter · Physics 2007-05-23 Bert Van Schaeybroeck , Achilleas Lazarides

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 determine the superfluid transition temperature $T_c$ and related finite temperature phase diagrams for the entire BCS-Bose Einstein condensation crossover in a homogeneous mixture of $^{6}$Li and $^{40}$K atoms with population…

Other Condensed Matter · Physics 2013-05-29 Hao Guo , Chih-Chun Chien , Qijin Chen , Yan He , K. Levin

We propose a simple bose-fermi model in two dimensions, with a coupling that converts pairs of opposite spin fermions into localized bosons and vice versa. We show that tracing out one of the degrees, either the bosons or fermions,…

Superconductivity · Physics 2020-10-23 Maciej M. Maśka , Nandini Trivedi

S-substituted FeSe superconductors in the tetragonal phase display several unique features among iron-based superconductors, particularly the presence of zero-energy excitations in the superconducting (SC) state. The recent concept of…

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

We present a systematic investigation of the effects of "nonmagnetic" impurities on the $s$-wave BCS-BEC crossover in atomic Fermi gases within a pairing fluctuation theory. Both pairing and impurity scattering $T$-matrices are treated…

Quantum Gases · Physics 2017-02-28 Yanming Che , Qijin Chen

Many-body effects may influence properties, such as scattering parameters, nature of pairing, etc., close to a Feshbach resonance in the fermion BEC-BCS crossover problem. We study effects such as these using a tractable crossing-symmetric…

Quantum Gases · Physics 2015-06-05 Renyuan Liao , Khandker F. Quader

We study Gaussian fluctuations of the zero-temperature attractive Fermi gas in the 2D BCS-BEC crossover showing that they are crucial to get a reliable equation of state in the BEC regime of composite bosons, bound states of fermionic…

Quantum Gases · Physics 2015-01-27 L. Salasnich , F. Toigo

The pairing of interacting fermions leading to superfluidity has two limiting regimes: the Bardeen-Cooper-Schrieffer (BCS) scheme for weakly interacting degenerate fermions and the Bose-Einstein condensation (BEC) of bosonic pairs of…

Superconductivity · Physics 2022-01-27 Y. Suzuki , K. Wakamatsu , J. Ibuka , H. Oike , T. Fujii , K. Miyagawa , H. Taniguchi , K. Kanoda

We theoretically study the Josephson effect in ultracold Fermi gases, where the two sides of the Josephson junction are independently tuned to different regions of the Bardeen-Cooper-Schrieffer (BCS)-Bose-Einstein condensation (BEC)…

Quantum Gases · Physics 2026-03-27 Tingyu Zhang , Hiroyuki Tajima

We theoretically investigate strong-coupling properties of an ultracold Fermi gas in the BCS-BEC crossover regime in the non-equilibrium steady state, being coupled with two fermion baths. By developing a non-equilibrium strong-coupling…

Quantum Gases · Physics 2020-01-09 Taira Kawamura , Ryo Hanai , Daichi Kagamihara , Daisuke Inotani , Yoji Ohashi

The diagrammatic t-matrix approximation has often been adopted to describe a dilute Fermi gas. This approximation, originally considered by Galitskii for a repulsive inter-particle interaction (Galitskii-1958), has later been widely…

Quantum Gases · Physics 2020-12-07 M. Pini , P. Pieri , G. Calvanese Strinati

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

BCS--Bose-Einstein condensation (BEC) crossover is effected by increasing pairing strength between fermions from weak to strong in the particle-particle channel. Here we study the effect of the particle-hole channel on the zero $T$ gap…

Quantum Gases · Physics 2016-05-27 Qijin Chen