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Related papers: Universal correlations along the BEC-BCS crossover

200 papers

We study theoretically the di-neutron spatial correlations and the crossover from superfluidity of neutron Cooper pairs in the $^1S_0$ pairing channel to Bose-Einstein condensation (BEC) of di-neutron pairs for both symmetric and neutron…

Nuclear Theory · Physics 2010-05-07 Bao Yuan Sun , Hiroshi Toki , Jie Meng

We investigate density fluctuations in a coherent ensemble of interacting fermionic atoms. Adapting the concept of full counting statistics, well-known from quantum optics and mesoscopic electron transport, we study second-order as well as…

Superconductivity · Physics 2022-08-19 W. Belzig , C. Schroll , C. Bruder

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 crossover from BCS pairing to molecular BEC in an atomic gas with two fermion species with masses $m_\up \ne m_\dn$ tuned through a Feshbach resonance. We present results for the T=0 equation of state as a function of the…

Quantum Gases · Physics 2015-05-13 Roberto B. Diener , Mohit Randeria

We discuss correlations between particles of different momentum in a superfluid fermi gas, accessible through noise measurements of absorption images of the expanded gas. We include two elements missing from the simplest treatment, based on…

Statistical Mechanics · Physics 2009-11-11 Austen Lamacraft

The pair correlation function of an expanding gas is investigated with an emphasis on the BEC-BCS crossover of a superfluid Fermi gas at zero temperature. At unitarity quantum Monte Carlo simulations reveal the occurrence of a sizable…

Soft Condensed Matter · Physics 2009-11-11 C. Lobo , I. Carusotto , S. Giorgini , A. Recati , S. Stringari

We investigate the zero-temperature properties of a dilute two-component Fermi gas with attractive interspecies interaction in the BCS-BEC crossover. We build an efficient parametrization of the energy per particle based on Monte Carlo data…

Soft Condensed Matter · Physics 2009-11-10 N. Manini , L. Salasnich

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

The primary work presented in this paper focuses on the calculation of density-density dynamical correlations in an attractive two dimensional Fermi gas in several physically interesting regimes, including the strongly correlated BEC-BCS…

Quantum Gases · Physics 2019-08-27 Ettore Vitali , Jimmy Gonzalez Nunez

We present Quantum Monte Carlo calculations of the properties of a two-component mass imbalanced Fermi gas, corresponding to the $^6$Li-$^{40}$K mixture. We compute the equation of state of the unpolarized system as a function of the…

Quantum Gases · Physics 2024-10-29 Stefano Gandolfi , Ryan Curry , Alexandros Gezerlis

From an extensive calculation of static properties of a trapped Fermi superfluid at zero temperature using a density-functional formulation, we demonstrate a universal behavior of its observables, such as energy, chemical potential, radius…

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

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 experimentally determined various thermodynamic quantities of interacting two-component fermions at the zero-temperature limit from the Bardeen-Cooper-Schrieffer (BCS) region to the unitarity limit. The obtained results are very accurate…

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 consider a two-component gas of fermionic atoms confined to a quasi-two-dimensional (quasi-2D) geometry by a harmonic trapping potential in the transverse direction. We construct a mean field theory of the BCS-BEC crossover at zero…

Quantum Gases · Physics 2014-03-04 Andrea M. Fischer , Meera M. Parish

We present a numerical study of the one-dimensional BCS-BEC crossover of a spin-imbalanced Fermi gas. The crossover is described by the Bose-Fermi resonance model in a real space representation. Our main interest is in the behavior of the…

Quantum Gases · Physics 2013-05-29 F. Heidrich-Meisner , A. E. Feiguin , U. Schollwoeck , W. Zwerger

We theoretically investigate the Bardeen-Cooper-Schrieffer (BCS) to Bose-Einstein condensation (BEC) crossover in a two-dimensional Fermi gas with the finite-range interaction by using the Hartree-Fock-Bogoliubov theory. Expanding the…

Quantum Gases · Physics 2024-03-20 Hikaru Sakakibara , Hiroyuki Tajima , Haozhao Liang

The pair-condensed unpolarized spin-$1/2$ Fermi gases have a collective excitation branch in their pair-breaking continuum (V.A. Andrianov, V.N. Popov, 1976). We study it at zero temperature, with the eigenenergy equation deduced from the…

Quantum Gases · Physics 2020-09-02 Yvan Castin , Hadrien Kurkjian

We present a measurement of the potential energy of an ultracold trapped gas of $^{40}$K atoms in the BCS-BEC crossover and investigate the temperature dependence of this energy at a wide Feshbach resonance, where the gas is in the…

Other Condensed Matter · Physics 2009-02-20 J. T. Stewart , J. P. Gaebler , C. A. Regal , D. S. Jin

We calculate the equation of state of a two-component Fermi gas with attractive short-range interspecies interactions using the fixed-node diffusion Monte Carlo method. The interaction strength is varied over a wide range by tuning the…

Soft Condensed Matter · Physics 2009-11-10 G. E. Astrakharchik , J. Boronat , J. Casulleras , S. Giorgini