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Related papers: BCS-BEC Crossover and the Unitary Fermi Gas

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We explore the paired superfluid phases of a Fermi gas in the presence of a continuous Rabi drive. We focus on the case where two components are strongly coupled by the drive, forming hybrid superpositions, and interacting with an uncoupled…

The crossover from Bardeen-Cooper-Schrieffer (BCS) superconductivity to Bose-Einstein condensation (BEC) is difficult to realize in quantum materials because, unlike in ultracold atoms, one cannot tune the pairing interaction. We realize…

We analyse a Bose-Einstein condensate (BEC) mixed with a superfluid two-component Fermi gas in the whole BCS-BEC cross-over. Using a quasiparticle random phase approximation combined with Beliaev theory to describe the Fermi superfluid and…

Quantum Gases · Physics 2015-05-07 J. J. Kinnunen , G. M. Bruun

The BCS-BEC crossover from strongly overlapping Cooper pairs to non-overlapping composite bosons in the strong coupling limit has been a long-standing issue of interacting many-body fermion systems. Recently, FeSe semimetal with hole and…

Superconductivity · Physics 2023-08-21 Y. Mizukami , M. Haze , O. Tanaka , K. Matsuura , D. Sano , J. Böker , I. Eremin , S. Kasahara , Y. Matsuda , T. Shibauchi

We investigate magnetic properties and strong coupling corrections in the BCS (Bardeen-Cooper-Schrieffer)-BEC (Bose-Einstein condensation) crossover regime of an ultracold Fermi gas. Within the framework of an extended $T$-matrix theory, we…

Quantum Gases · Physics 2015-10-16 Hiroyuki Tajima , Ryo Hanai , Ryota Watanabe , Yoji Ohashi

We investigate Bardeen-Cooper-Schrieffer (BCS)- Bose-Einstein condensation (BEC) crossover in a two-band superfluid Fermi gas with an energy shift between the bands. When the intraband coupling in the cold (first) band is fixed as weak, we…

Superconductivity · Physics 2019-10-09 Yuriy Yerin , Hiroyuki Tajima , Pierbiagio Pieri , Andrea Perali

We study the superfluid state of atomic Fermi gases using a BCS-BEC crossover theory. Our approach emphasizes non-condensed fermion pairs which strongly hybridize with their (Feshbach-induced) molecular boson counterparts. These pairs lead…

Soft Condensed Matter · Physics 2011-09-13 Jelena Stajic , J. N. Milstein , Qijin Chen , M. L. Chiofalo , M. J. Holland , K. Levin

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

We investigate the Bose-Einstein condensation of Fermionic pairs in a uniform two-component Fermi gas obtaining an explicit formula for the condensate density as a function of the chemical potential and the energy gap. We analyze the…

Statistical Mechanics · Physics 2009-11-11 Luca Salasnich , Nicola Manini , Alberto Parola

We investigate the quantum and thermal phase diagram of fermionic polar molecules loaded in a bilayer trapping potential with perpendicular dipole moment. We use both a BCS theory approach that is most realiable at weak-coupling and a…

Quantum Gases · Physics 2012-01-13 N. T. Zinner , B. Wunsch , D. Pekker , D. -W. Wang

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

This article is written as a Lecture given in the 2006 Varenna Summer School on "Ultracold Fermi Gases". Here we present a review of BCS--Bose Einstein condensation (BEC) crossover theory with emphasis on finite temperature effects. We…

Strongly Correlated Electrons · Physics 2011-09-13 K. Levin , Qijin Chen

In a trapped atomic Fermi gas, one can tune continuously via a Feshbach resonance the effective pairing interaction between fermionic atoms from very weak to very strong. As a consequence, the low temperature superfluidity evolves…

Quantum Gases · Physics 2011-01-17 Yi Yu , Qijin Chen

We study BCS-BEC crossover in the strongly correlated regime of two component rotating Fermi gases. We predict that the strong correlations induced by rotation will have the effect of modifying the crossover region relative to the…

Other Condensed Matter · Physics 2007-05-23 S. G. Bhongale , S. J. J. M. F. Kokkelmans

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 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

The transition from the weakly interacting BCS regime to the strongly interacting unitary regime is explored for ultracold trapped Fermi gases assuming a normal mode description of the gas instead of the conventional Cooper pairing. The…

Quantum Gases · Physics 2022-06-27 D. K. Watson

We investigate the zero-temperature quasiparticle properties of a mobile impurity immersed in a strongly interacting Fermi superfluid at the crossover from a Bose-Einstein condensate (BEC) to a Bardeen--Cooper--Schrieffer (BCS) superfluid,…

Quantum Gases · Physics 2022-02-18 Hui Hu , Jia Wang , Jing Zhou , Xia-Ji Liu

We theoretically investigate the isothermal compressibility $\kappa_{T}$ in the normal state of an ultracold Fermi gas. Including pairing fluctuations, as well as preformed-pair formations, within the framework of the self-consistent…

Quantum Gases · Physics 2022-09-09 Daichi Kagamihara , Ryohei Sato , Koki Manabe , Hiroyuki Tajima , 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