Dynamical density fluctuations of superfluids near the critical velocity

Yusuke Kato, Shohei Watabe

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)


We propose a stability criterion of superfluids in condensed Bose-Einstein systems, which incorporates the spectral function or the autocorrelation function of the local density. Within the Gross-Pitaevskii-Bogoliubov theory, we demonstrate the validity of our criterion for the soliton-emission instability, with use of explicit forms of zero modes of the Bogoliubov equation and a dynamical scaling near the saddle-node bifurcation. We also show that the criterion is applicable to the Landau phonon instability and the Landau roton instability within the single-mode approximation.

Original languageEnglish
Article number035302
JournalPhysical Review Letters
Issue number3
Publication statusPublished - 2010 Jul 16
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy(all)


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