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Related papers: BEC-BCS Crossover in the Epsilon Expansion

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We systematically study relativistic two-species fermions with tunable attractive interactions and number-density asymmetry at zero temperature. In general, a Bardeen-Cooper-Schrieffer (BCS) - Bose-Einstein Condensation (BEC) - relativistic…

High Energy Physics - Phenomenology · Physics 2014-11-18 Hao Guo , Chih-Chun Chien , Yan He

We determine the phase diagram of strongly correlated fermions in the crossover from Bose-Einstein condensates of molecules (BEC) to Cooper pairs of fermions (BCS) utilizing an artificial neural network. By applying advanced image…

Quantum Gases · Physics 2023-10-25 M. Link , K. Gao , A. Kell , M. Breyer , D. Eberz , B. Rauf , M. Köhl

We perform a detailed study of the collective mode across the whole BEC-BCS crossover in fermionic gases at zero temperature, covering the whole range of energy beyond the linear regime. This is done on the basis of the dynamical BCS model.…

Other Condensed Matter · Physics 2014-11-17 R. Combescot , M. Yu. Kagan , S. Stringari

The Josephson relation for the superfluid density is derived for a Fermi superfluid in the BCS-BEC crossover. This identity extends the original Josephson relation for Bose superfluids. It gives a simple exact relation between the…

Other Condensed Matter · Physics 2008-12-12 Edward Taylor

We investigate magnetic properties and effects of pairing fluctuations in the BCS (Bardeen-Cooper-Schrieffer)-BEC (Bose-Einstein condensation) crossover regime of an ultracold Fermi gas. Recently, Liu and Hu, and Parish, pointed out that…

Quantum Gases · Physics 2015-06-11 Takashi Kashimura , Ryota Watanabe , Yoji Ohashi

We investigate the ground state of interacting spin-$\half$ fermions (3D) at a finite density ($\rho \sim \kf^3$) in the presence of a uniform non-Abelian gauge field. The gauge field configuration (GFC) described by a vector $\blam \equiv…

Quantum Gases · Physics 2011-07-27 Jayantha P. Vyasanakere , Shizhong Zhang , Vijay B. Shenoy

The effect of particle-hole fluctuations for the BCS-BEC crossover is investigated by use of functional renormalization. We compute the critical temperature for the whole range in the scattering length $a$. On the BCS side for small…

Superconductivity · Physics 2009-01-23 S. Floerchinger , M. Scherer , S. Diehl , C. Wetterich

Thermodynamics of the unitary Fermi gas at finite temperature is investigated from the perspective of the expansion over epsilon=4-d with d being the dimensionality of space. We show that the thermodynamics is dominated by bosonic…

Other Condensed Matter · Physics 2009-02-05 Yusuke Nishida

The static and dynamic structure factors of an interacting Fermi gas along the BCS-BEC crossover are calculated at momentum transfer $\hbar{\bf k}$ higher than the Fermi momentum. The spin structure factor is found to be very sensitive to…

Other Condensed Matter · Physics 2009-11-11 R. Combescot , S. Giorgini , S. Stringari

We introduce a quasi-analytic nonlinear Schr\"odinger equation with beyond mean-field corrections to describe the dynamics of a zero-temperature dilute superfluid Fermi gas in the crossover from the weak-coupling Bardeen-Cooper-Schrieffer…

Other Condensed Matter · Physics 2009-11-13 S. K. Adhikari

We derive an expression for the superfluid density of a uniform two-component Fermi gas through the BCS-BEC crossover in terms of the thermodynamic potential in the presence of an imposed superfluid flow. Treating the pairing fluctuations…

Other Condensed Matter · Physics 2008-12-12 E. Taylor , A. Griffin , N. Fukushima , Y. Ohashi

We review the BCS to Bose Einstein condensation (BEC) crossover scenario which is based on the well known crossover generalization of the BCS ground state wavefunction $\Psi_0$. While this ground state has been summarized extensively in the…

Superconductivity · Physics 2011-09-13 Qijin Chen , Jelena Stajic , Shina Tan , Kathryn Levin

We analyze the evolution of the dynamics of a neutral s-wave superconductor between BCS and BEC regimes. We consider 2d case, when BCS-BEC crossover occurs already at weak coupling as a function of the ratio of the two scales -- the Fermi…

Superconductivity · Physics 2019-05-22 Dmitry Mozyrsky , Andrey V. Chubukov

We extend our previous investigations of fermionic condensation in broad Feshbach resonances by using the two-channel model developed for narrow Feshbach resonances. We investigate two crossovers: the BCS-BEC crossover by changing the…

Quantum Gases · Physics 2012-11-19 Luca Salasnich

In paired Fermi systems, strong many-body effects exhibit in the crossover regime between the Bardeen-Cooper-Schrieffer (BCS) and the Bose-Einstein condensation (BEC) limits. The concept of the BCS-BEC crossover, which is studied…

Superconductivity · Physics 2019-10-16 Shuyuan Zhang , Guangyao Miao , Jiaqi Guan , Xiaofeng Xu , Bing Liu , Fang Yang , Weihua Wang , Xuetao Zhu , Jiandong Guo

We investigate chiral symmetry breaking in a model of Dirac fermions with a complexified coupling constant whose imaginary part represents dissipation. We introduce a chiral chemical potential and observe that for real coupling a…

High Energy Physics - Theory · Physics 2021-03-16 Takuya Kanazawa

Spherical collapse of the Bose-Einstein Condensate (BEC) dark matter model is studied in the Thomas Fermi approximation. The evolution of the overdensity of the collapsed region and its expansion rate are calculated for two scenarios. We…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-11 Rodolfo C. de Freitas , Hermano Velten

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

Strong evidence for pairing and superfluidity has recently been found in atomic Fermi gases at the BCS-BEC crossover both in collective modes and RF excitation energies. It is argued that the scale for the effective pairing gaps measured in…

Superconductivity · Physics 2009-11-10 H. Heiselberg

We develop a self-consistent theory unifying the description of a quantum Fermi gas in the presence of a Fano-Feshbach resonance in the whole phase diagram ranging from BCS to BEC type of superfluidity and from narrow to broad resonances,…

Quantum Gases · Physics 2019-08-29 Pietro Maria Bonetti , Maria Luisa Chiofalo
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