Stability criterion for superfluidity based on the density spectral function

Shohei Watabe, Yusuke Kato

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)

Abstract

We study a stability criterion hypothesis for superfluids expressed in terms of the local density spectral function In(r,ω) that is applicable to both homogeneous and inhomogeneous systems. We evaluate the local density spectral function in the presence of a one-dimensional repulsive or attractive external potential within Bogoliubov theory, using solutions for the tunneling problem. We also evaluate the local density spectral function using an orthogonal basis, and calculate the autocorrelation function C n(r,t). When superfluids in a d-dimensional system flow below a threshold, In(r,ω)â̂ωd holds in the low-energy regime and Cn(r,t)â̂1/td+1 holds in the long-time regime. However, when superfluids flow with the critical current, In(r,ω)â̂ωβ holds in the low-energy regime and Cn(r,t)â̂1/tβ+1 holds in the long-time regime with β<d. These results support the stability criterion hypothesis recently proposed.

Original languageEnglish
Article number063612
JournalPhysical Review A - Atomic, Molecular, and Optical Physics
Volume88
Issue number6
DOIs
Publication statusPublished - 2013 Dec 6
Externally publishedYes

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

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