1110.2788 (Michael Schecter et al.)

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

Michael Schecter, Alex Kamenev, Dimitri Gangardt, Austen Lamacraft

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 $M_\mathrm{c}$, 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 $MView original: http://arxiv.org/abs/1110.2788