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Related papers: BCS-BEC Crossover Effects and Pseudogap in Neutron…

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We derive a phase diagram for the pseudogap onset temperature $T^*$ (associated with the breakdown of the Fermi liquid state, due to strong pairing correlations) and the superconducting instability, $T_c$, as a function of variable pairing…

Superconductivity · Physics 2007-05-23 Jiri Maly , Boldizsar Janko , K. Levin

We investigate the superfluid phase transition and effects of mass imbalance in the BCS (Bardeen-Cooper-Schrieffer)-BEC (Bose-Einstein condensation) crossover regime of an cold Fermi gas. We point out that the Gaussian fluctuation theory…

Quantum Gases · Physics 2013-07-11 Ryo Hanai , Takashi Kashimura , Ryota Watanabe , Daisuke Inotani , Yoji Ohashi

We investigate pairing fluctuation effects in a two band fermionic system, where a shallow band in the Bardeen--Cooper--Schrieffer--Bose--Einstein condensation (BCS-BEC) crossover regime is coupled with a weakly interacting deep band.…

Superconductivity · Physics 2020-01-23 Hiroyuki Tajima , Andrea Perali , Pierbiagio Pieri

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

The physics of the crossover between weak-coupling Bardeen-Cooper-Schrieffer (BCS) and strong-coupling Bose-Einstein-condensate (BEC) limits gives a unified framework of quantum bound (superfluid) states of interacting fermions. This…

We review the properties of neutron matter in the low-density regime. In particular, we revise its ground state energy and the superfluid neutron pairing gap, and analyze their evolution from the weak to the strong coupling regime. The…

Nuclear Theory · Physics 2021-04-30 Isaac Vidana

We investigate the uniform spin susceptibility $\chi_{\rm s}$ in the BCS (Bardeen-Cooper-Schrieffer)-BEC (Bose-Einstein condensation) crossover regime of an ultracold Fermi gas. Including pairing fluctuations within the framework of an…

Quantum Gases · Physics 2015-10-16 H. Tajima , T. Kashimura , R. Hanai , R. Watanabe , Y. Ohashi

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 investigate the finite-temperature superfluid behavior of ultracold atomic Fermi gases in quasi-two-dimensional Lieb lattices with a short-range attractive interaction, using a pairing fluctuation theory within the BCS-BEC crossover…

Quantum Gases · Physics 2024-01-09 Hao Deng , Lin Sun , Chuping Li , Yuxuan Wu , Junru Wu , Qijin Chen

We investigate the specific heat at constant volume $C_V$ in the BCS (Bardeen-Cooper-Schrieffer)-BEC (Bose-Einstein condensation) crossover regime of an ultracold Fermi gas above the superfluid phase transition temperature $T_{\rm c}$.…

Quantum Gases · Physics 2016-02-03 Pieter van Wyk , Hiroyuki Tajima , Ryo Hanai , Yoji Ohashi

We study the superfluid critical temperature in a two-band attractive Fermi system with strong pairing fluctuations associated with both interband and intraband couplings. We focus specifically on a configuration where the intraband…

Quantum Gases · Physics 2019-06-05 Hiroyuki Tajima , Yuriy Yerin , Andrea Perali , Pierbiagio Pieri

The two-species Fermi gas with attractive short-range interactions in two spatial dimensions provides a paradigmatic system for the understanding of strongly correlated Fermi superfluids in two dimensions. It is known to exhibit a BEC-BCS…

Quantum Gases · Physics 2025-01-08 S. Ramachandran , S. Jensen , Y. Alhassid

We review briefly the properties of a mixture of mutually interacting bosons (bound electron pairs) and itinerant fermions on a lattice (the boson-fermion model). The calculations of the superconducting phase transition temperature…

Superconductivity · Physics 2019-12-12 R. Micnas

We review recent developments in the field of ultracold atomic Fermi gases. As the cold atom system evolves from BCS to Bose-Einstein condensation (BEC), the behavior of the thermodynamics, and the particle density profiles evolves smoothly…

Superconductivity · Physics 2011-09-13 K. Levin , Qijin Chen

We show how to describe the $T \neq 0$ behavior associated with the usual BCS- Bose Einstein condensation (BEC) crossover ground state. We confine our attention here to the BEC and near-BEC regime where analytical calculations are possible.…

Soft Condensed Matter · Physics 2011-09-13 Jelena Stajic , Qijin Chen , K. Levin

We obtain the critical magnetic field required for complete destruction of $S$-wave pairing in neutron matter, thereby setting limits on the pairing and superfluidity of neutrons in the crust and outer core of magnetars. We find that for…

Nuclear Theory · Physics 2016-02-02 Martin Stein , Armen Sedrakian , Xu-Guang Huang , John W. Clark

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 address the thermodynamics, density profiles and superfluid density of trapped fermions undergoing BCS-BEC crossover, with and without population imbalance. Our approach represents a fully consistent treatment of "pseudogap effects",…

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

The non-relativistic $G_0 G$ formalism of BCS-BEC crossover at finite temperature is extended to relativistic fermion systems. The uncondensed pairs contribute a pseudogap to the fermion excitations. The theory recovers the BCS mean field…

High Energy Physics - Phenomenology · Physics 2008-11-26 Lianyi He , Pengfei Zhuang

We investigate the Bose-Einstein condensation of fermionic pairs in three different superfluid systems: ultracold and dilute atomic gases, bulk neutron matter, and neutron stars. In the case of dilute gases made of fermionic atoms the…

Quantum Gases · Physics 2014-09-30 Luca Salasnich