Jeudi 03 juillet 2014 à 10h15
Salle 234, Ecole de Physique

Mobile impurity propagation in a one-dimensional quantum gas

Oleksandr Gamayun, Lancaster University, UK

We investigate the time evolution of the momentum of an impurity atom injected into a degenerate Tonks-Girardeau gas. We establish that given an initial momentum $p_0$ the impurity relaxes to a steady state with a non-vanishing momentum $p_infty$. The nature of the steady state is found to be drastically different for integrable and non-integrable impurity models, which is due to multiple coherent scattering processes leading to a resonant interaction between the impurity and the host in the integrable case. The dependence of $p_infty$ on $p_0$ remains non-trivial even in the limit of vanishing interaction between the impurity and host particles. In this limit $p_infty(p_0)$ is found explicitly and the case of the external force applied to the impurities analyzed as well.