Spin-gap phenomenon in a strongly interacting ultracold Fermi gas

H. Tajima, R. Hanai, Y. Ohashi

Research output: Contribution to journalConference article

Abstract

We investigate magnetic properties of a strongly interacting ultracold Fermi gas. Within the framework of an extended T-matrix approximation, we calculate the spin susceptibility χ in the unitarity limit. We show that effects of pairing fluctuations on this magnetic quantity are quite different in between the normal state and the superfluid phase. In the normal state, pairing fluctuations cause spin-gap phenomenon near the superfluid phase transition temperature Tc, where χ is anomalously suppressed. In the superfluid phase, on the other hand, the ordinary suppression of χ by the BCS energy gap is weakened by pairing fluctuations, because they induce finite density of states inside the gap. Our results indicate that the spin susceptibility is a useful quantity for the study of pairing fluctuations in the BCS-BEC crossover regime of an ultracold Fermi gas.

Original languageEnglish
Article number012019
JournalJournal of Physics: Conference Series
Volume568
DOIs
Publication statusPublished - 2014 Jan 1
Event27th International Conference on Low Temperature Physics, LT 2014 - Buenos Aires, Argentina
Duration: 2014 Aug 62014 Aug 13

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ASJC Scopus subject areas

  • Physics and Astronomy(all)

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