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Related papers: Rabi coupled fermions in the BCS-BEC crossover

200 papers

We investigate strong pairing fluctuations and effects of a harmonic trap in the superfluid phase of an ultracold Fermi gas. Including amplitude and phase fluctuations of the inhomogeneous superfluid order parameter $\Delta(r)$ in a trap…

Quantum Gases · Physics 2015-06-11 Ryota Watanabe , Shunji Tsuchiya , 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

This report adresses topics and questions of common interest in the fields of ultra-cold gases and nuclear physics in the context of the BCS-BEC crossover. The BCS-BEC crossover has recently been realized experimentally, and essentially in…

We consider a dilute atomic gas of two species of fermions with unequal concentrations under a Feshbach resonance. We find that the system can have distinct properties due to the unbound fermions. The uniform state is stable only when…

Superconductivity · Physics 2009-11-11 C. -H. Pao , Shin-Tza Wu , S. -K. Yip

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 investigate pairing in a strongly interacting two-component Fermi gas with positive scattering length. In this regime, pairing occurs at temperatures above the superfluid critical temperature; unbound fermions and pairs coexist in…

We present a theoretical review of the recent progress in nonequilibrium BCS (Bardeen-Cooper-Schrieffer)-BEC (Bose-Einstein condensation) crossover physics. As a paradigmatic example, we consider a strongly interacting driven-dissipative…

Quantum Gases · Physics 2025-03-07 Taira Kawamura , Yoji Ohashi

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 examine the effect of the trapping potential on the critical temperature, $T_C$, for the BCS transition to a superfluid state in trapped atomic gases of fermions. $T_C$ for an arbitrary power law trap is calculated in the Thomas-Fermi…

Superconductivity · Physics 2009-11-07 C. P. Search , H. Pu , W. Zhang , B. P. Anderson , P. Meystre

Using a time-dependent linear (Rabi) coupling between the components of a weakly interacting multicomponent Bose-Einstein condensate (BEC), we propose a protocol for transferring the wavefunction of one component to the other. This "Rabi…

Other Condensed Matter · Physics 2008-11-21 H. E. Nistazakis , Z. Rapti , D. J. Frantzeskakis , P. G. Kevrekidis , P. Sodano , A. Trombettoni

We theoretically investigate strong-coupling effects on specific heat at constant volume $C_{\rm V}$ in a superfluid Fermi gas with a tunable interaction associated with Feshbach resonance. Including fluctuations of the superfluid order…

Quantum Gases · Physics 2019-05-22 Daisuke Inotani , Pieter van Wyk , Yoji Ohashi

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 unconventional superfluidity in a gas of Fermi atoms with an anisotropic p-wave Feshbach resonance. Including the p-wave Feshbach resonance as well as the associated three kinds of quasi-molecules with finite orbital angular…

Other Condensed Matter · Physics 2009-11-10 Yoji Ohashi

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

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 present a theory of a two-component atomic Fermi gas with tunable attractive contact interactions on a spherical shell going through the Bardeen-Cooper-Schrieffer (BCS) - Bose Einstein condensation (BEC) crossover, inspired by the…

Quantum Gases · Physics 2022-04-01 Yan He , Hao Guo , Chih-Chun Chien

We consider the phase-transition-like behaviour in the Rabi model containing a single two-level system, or qubit, and a single harmonic oscillator. The system experiences a sudden transition from an uncorrelated state to an increasingly…

Quantum Physics · Physics 2013-12-30 S. Ashhab

We investigate a two-component Fermi gas with unequal spin populations along the BCS-BEC crossover. By using the extended BCS equations and the concept of off-diagonal-long-range-order we derive a formula for the condensate number of Cooper…

Quantum Gases · Physics 2014-09-30 G. Bighin , L. Salasnich , G. Mazzarella , L. Dell'Anna

We investigate the superfluid phase transition in a gas of Fermi atoms loaded on a three-dimensional optical lattice. When the lattice potential is strong, this system can be well described by an attractive Hubbard model. In this model, we…

Materials Science · Physics 2008-03-17 H. Tamaki , Y. Ohashi , K. Miyake

In this review article we consider theoretically and give experimental support to the models of the Fermi-Bose mixtures and the BCS-BEC crossover compared with the strong-coupling approach, which can serve as the cornerstones on the way…

Superconductivity · Physics 2019-06-05 Maxim Yu Kagan , Antonio Bianconi