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Related papers: Local-field Theory of the BCS-BEC Crossover

200 papers

We report on precision measurements of the frequency of the radial compression mode in a strongly interacting, optically trapped Fermi gas of Li-6 atoms. Our results allow for a test of theoretical predictions for the equation of state in…

Other Condensed Matter · Physics 2009-03-24 A. Altmeyer , S. Riedl , C. Kohstall , M. Wright , R. Geursen , M. Bartenstein , C. Chin , J. Hecker Denschlag , R. Grimm

We systematically study the BCS-BEC crossover and the quantum phase transition in ultracold 6Li and 40K atoms across a wide Feshbach resonance. The background scattering lengths for 6Li and 40K have opposite signs, which lead to very…

Other Condensed Matter · Physics 2007-05-23 W. Yi , L. -M. Duan

We report results of quantum Monte Carlo calculations of the ground state of dilute Fermi gases with attractive short range two-body interactions. The strength of the interaction is varied to study different pairing regimes which are…

Atomic Physics · Physics 2009-02-05 S. Y. Chang , J. Carlson , V. R. Pandharipande , K. E. Schmidt

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 develop a simple, mean-field-like theory for the normal phase of a unitary Fermi gas by deriving a self-consistent equation for its self-energy via a momentum-dependent coupling constant for both attractive and repulsive universal…

Quantum Gases · Physics 2013-01-09 Erik M. Weiler , Theja N. De Silva

We report on experimental studies on the collective behavior of a strongly interacting Fermi gas with tunable interactions and variable temperature. A scissors mode excitation in an elliptical trap is used to characterize the dynamics of…

Other Condensed Matter · Physics 2009-03-24 M. J. Wright , S. Riedl , A. Altmeyer , C. Kohstall , E. R. Sanchez Guajardo , J. Hecker Denschlag , R. Grimm

Fermi systems in the crossover regime between weakly coupled Bardeen-Cooper-Schrieffer (BCS) and strongly coupled Bose-Einstein-condensate (BEC) limits are among the most fascinating objects to study the behavior of an assembly of strongly…

We study the spontaneous formation of vortices during the superfluid condensation in a trapped fermionic gas subjected to a rapid thermal quench via evaporative cooling. Our work is based on the numerical solution of the time dependent…

Quantum Gases · Physics 2015-03-18 A. Glatz , H. L. L. Roberts , I. S. Aranson , K. Levin

We use the standard fermionic and boson-fermion Hamiltonians to study the BCS-BEC cross-over near the 202 G resonance in a two-component mixture of fermionic 40K atoms employed in the experiment of C.A. Regal et al., Phys. Rev. Lett. 92,…

Superconductivity · Physics 2009-02-05 Marzena H. Szymanska , Krzysztof Goral , Thorsten Koehler , Keith Burnett

In this paper, we study the properties of a phase slip in a superfluid Fermi gas near a Feshbach resonance. The phase slip can be generated by the phase imprinting method. Below the superfluid transition temperature, it appears as a dip in…

Other Condensed Matter · Physics 2009-11-10 Lan Yin , Ping Ao

A review on superfluidity and the BEC-BCS crossover in ultracold Fermi gases.

Other Condensed Matter · Physics 2009-11-13 Wolfgang Ketterle , Martin W. Zwierlein

We formulate a generalized mean-field theory of a mixture of fermionic and bosonic atoms, in which the fermion-boson interaction can be controlled by a Feshbach resonance. The theory correctly accounts for molecular binding energies of the…

Other Condensed Matter · Physics 2009-11-13 D. C. E. Bortolotti , A. V. Avdeenkov , J. L. Bohn

We present a mean field approach based on pairs of fermionic atoms to describe condensates in the BEC-BCS crossover regime. By introducing an effective potential, the mean field equation allows us to calculate the chemical potential, the…

Superconductivity · Physics 2007-05-23 Cheng Chin

We perform a variational quantum Monte Carlo simulation of the transition from a Bardeen-Cooper-Schrieffer superfluid (BCS) to a Bose-Einstein condensate (BEC) at zero temperature. The model Hamiltonian involves an attractive short range…

Other Condensed Matter · Physics 2008-12-01 R. Jauregui , R. Paredes , L. Rosales-Zarate , G. Toledo Sanchez

In this work dark soliton collisions in a one-dimensional superfluid Fermi gas are studied across the BEC-BCS crossover by means of a recently developed finite-temperature effective field theory [S. N. Klimin, J. Tempere, G. Lombardi, J. T.…

Quantum Gases · Physics 2018-07-06 Wout Van Alphen , Giovanni Lombardi , Sergei N. Klimin , Jacques Tempere

We investigate pseudogap phenomena originating from pairing fluctuations in the BCS-BEC crossover regime of a two-dimensional Fermi gas in a harmonic trap. Including pairing fluctuations within a $T$-matrix theory and effects of a trap…

Quantum Gases · Physics 2015-06-05 Ryota Watanabe , Shunji Tsuchiya , Yoji Ohashi

We show that both DC and AC Josephson effects with superfluid Fermi atoms in the BCS-BEC crossover can be described at zero temperature by a nonlinear Schrodinger equation (NLSE). By comparing our NLSE with mean-field extended BCS…

Other Condensed Matter · Physics 2009-04-12 L. Salasnich , F. Ancilotto , N. Manini , F. Toigo

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 determine the size of the critical region of the superfluid transition in the BCS-BEC crossover of a three-dimensional fermion gas, using a renormalization-group approach to a bosonic theory of pairing fluctuations. For the unitary Fermi…

Quantum Gases · Physics 2016-03-08 T. Debelhoir , N. Dupuis

Both the trapping geometry and the interatomic interaction strength of a dilute ultracold fermionic gas can be well controlled experimentally. When the interactions are tuned to strong attraction, Cooper pairing of neutral atoms takes place…

Other Condensed Matter · Physics 2007-05-23 J. Tempere , J. T. Devreese