English
Related papers

Related papers: Finite temperature damping of collective modes of …

200 papers

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

We discuss the BCS-BEC crossover in a degenerate Fermi gas of two hyperfine states interacting close to a Feshbach resonance. This system has quasi-molecular Bosons associated with a Feshbach resonance, and this kinds of coupled…

Soft Condensed Matter · Physics 2016-08-31 Y. Ohashi , A. Griffin

The present work aims at providing a systematic analysis of the current density versus momentum characteristics for a fermionic superfluid throughout the BCS-BEC crossover, even in the fully homogeneous case. At low temperatures, where…

Superconductivity · Physics 2024-03-20 Leonardo Pisani , Verdiana Piselli , Giancarlo Calvanese Strinati

The amplitude mode of a fermionic superfluid, analogous to the Higgs Boson, becomes undamped in the strong coupling regime when its frequency is pushed inside the BCS energy gap. We argue that this is the case in cold gases due to the…

Superconductivity · Physics 2007-05-23 R. A. Barankov , L. S. Levitov

Thermodynamic properties of an ultracold Fermi gas in a harmonic trap are calculated within a local density approximation, using a conserving many-body formalism for the BCS to BEC crossover problem, which has been developed by Haussmann et…

Statistical Mechanics · Physics 2009-11-13 R. Haussmann , W. Zwerger

The low-energy modes of a spin-imbalanced superfluid Fermi gas in the Bardeen-Cooper-Schrieffer (BCS) side are studied. The gas is assumed to be sufficiently dilute so that the pairing of atoms can be considered effective only in s-wave…

Quantum Gases · Physics 2017-12-06 F. Matera , M. F. Wagner

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

The thermodynamic potential is calculated for a uniform superfluid gas of fermi atoms from the mean field BCS equations including corrections from induced interactions, Hartree-Fock energies and quasiparticle selfenergies. The entropy,…

Superconductivity · Physics 2007-05-23 H. Heiselberg

We study an effective field theory describing cold fermionic atoms near a Feshbach resonance. The theory gives a unique description of the dynamics in the limit that the energy of the Feshbach resonance is tuned to be twice that of the…

Condensed Matter · Physics 2016-08-31 Deog Ki Hong , Stephen D. H. Hsu

Sound propagation is a macroscopic manifestation of the interplay between the equilibrium thermodynamics and the dynamical transport properties of fluids. Here, for a two-dimensional system of ultracold fermions, we calculate the first and…

Quantum Gases · Physics 2021-07-21 A. Tononi , A. Cappellaro , G. Bighin , L. Salasnich

A strongly interacting Fermi gas, such as that of cold atoms operative near a Feshbach resonance, is difficult to study by perturbative many-body theory to go beyond mean field approximation. Here I develop an effective field theory for the…

Other Condensed Matter · Physics 2007-05-23 W. Vincent Liu

We have observed condensation of fermionic atom pairs in the BCS-BEC crossover regime. A trapped gas of fermionic 40K atoms is evaporatively cooled to quantum degeneracy and then a magnetic-field Feshbach resonance is used to control the…

Statistical Mechanics · Physics 2009-11-10 C. A. Regal , M. Greiner , D. S. Jin

A gas of interacting ultracold fermions can be tuned into a strongly interacting regime using a Feshbach resonance. Here we theoretically study quasiparticle transport in a system of two reservoirs of interacting ultracold fermions on the…

Quantum Gases · Physics 2016-09-19 Tibor Sekera , Christoph Bruder , Wolfgang Belzig

Using an effective field theory we describe the low energy bosonic excitations in a three dimensional ultra-cold mixture of spin-1 bosons and spin-1/2 fermions. We establish an interesting fermionic excitation induced generic damping of the…

Quantum Gases · Physics 2015-07-20 J. H. Pixley , Xiaopeng Li , S. Das Sarma

We examine collective modes, stability, and BCS pairing in a quasi-two-dimensional gas of dipolar fermions aligned by an external field. By using the (conserving) Hartree-Fock approximation, which treats direct and exchange interactions on…

Quantum Gases · Physics 2011-12-26 L. M. Sieberer , M. A. Baranov

We investigate dipole oscillations of ultracold Fermi gases along the BEC-BCS crossover through disordered potentials. We observe a disorder-induced damping of oscillations as well as a change of the fundamental Kohn-mode frequency. The…

We evaluate the frequencies of collective modes and the anisotropic expansion rate of a harmonically trapped Fermi superfluid at varying coupling strengths across a Feshbach resonance driving a BCS-BEC crossover. The equations of motion for…

Statistical Mechanics · Physics 2007-05-23 Hui Hu , A. Minguzzi , Xia-Ji Liu , M. P. Tosi

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 study a system of ultracold fermionic Potassium (40K) atoms in a three-dimensional optical lattice in the vicinity of an s-wave Feshbach resonance. Close to resonance, the system is described by a multi-band Bose-Fermi Hubbard…

Quantum Gases · Physics 2010-06-30 I. Titvinidze , M. Snoek , W. Hofstetter

We consider the BCS-BEC crossover for a system of trapped Fermi atoms at finite temperature, both below and above the superfluid critical temperature, by including fluctuations beyond mean field. We determine the superfluid critical…

Superconductivity · Physics 2009-02-20 A. Perali , P. Pieri , L. Pisani , G. C. Strinati