Critical velocity of a mobile impurity in one-dimensional quantum liquids

M. Schecter, A. Kamenev, D. M. Gangardt, A. Lamacraft

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39 Scopus citations


We study the notion of superfluid critical velocity in one spatial dimension. It is shown that, for heavy impurities with mass M exceeding a critical mass M c, the dispersion develops periodic metastable branches resulting in dramatic changes of dynamics in the presence of an external driving force. In contrast to smooth Bloch oscillations for M<M c, a heavy impurity climbs metastable branches until it reaches a branch termination point or undergoes a random tunneling event, both leading to an abrupt change in velocity and an energy loss. This is predicted to lead to a nonanalytic dependence of the impurity drift velocity on small forces.

Original languageEnglish (US)
Article number207001
JournalPhysical review letters
Issue number20
StatePublished - May 14 2012


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