Superfluid properties of an ultracold Fermi gas in the BCS-BEC crossover region

Yoji Ohashi, Naoki Fukushima

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

We investigate superfluid properties of a two-component Fermi gas in the BCS-BEC crossover region. Including strong-coupling effects within a Gaussian fluctuation approximation, we self-consistently determine the superfluid order parameter and chemical potential at finite temperatures. Using these self-consistent solutions, we calculate single-particle excitations, as well as collective mode, over the entire BCS-BEC crossover region. As one increases the strength of a pairing interaction, we show that, while the single-particle excitation gap becomes large, the velocity of collective Goldstone mode becomes small. As a result, the origin of temperature dependence of a physical quantity continuously changes from single-particle excitations to collective excitations, as one passes through the BCS-BEC crossover region. To see this, we examine the superfluid density.

Original languageEnglish
Title of host publicationProceedings of the 9th International Symposium on Foundations of Quantum Mechanics in the Light of New Technology, ISQM-Tokyo 2008
PublisherWorld Scientific Publishing Co. Pte Ltd
Pages18-23
Number of pages6
ISBN (Print)981428212X, 9789814282123
Publication statusPublished - 2009
Event9th International Symposium on Foundations of Quantum Mechanics in the Light of New Technology, ISQM-Tokyo 2008 - Hatoyama, Saitama, Japan
Duration: 2008 Aug 252008 Aug 28

Other

Other9th International Symposium on Foundations of Quantum Mechanics in the Light of New Technology, ISQM-Tokyo 2008
CountryJapan
CityHatoyama, Saitama
Period08/8/2508/8/28

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Keywords

  • BCS-BEC crossover
  • Superfluid density
  • Superfluid Fermi gas

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Cite this

Ohashi, Y., & Fukushima, N. (2009). Superfluid properties of an ultracold Fermi gas in the BCS-BEC crossover region. In Proceedings of the 9th International Symposium on Foundations of Quantum Mechanics in the Light of New Technology, ISQM-Tokyo 2008 (pp. 18-23). World Scientific Publishing Co. Pte Ltd.