Interaction-induced Bloch oscillation in a harmonically trapped and fermionized quantum gas in one dimension

Abstract

Motivated by a recent experiment by F. Meinert et al, arxiv:1608.08200, we study the dynamics of an impurity moving in the background of a harmonically trapped one-dimensional Bose gas in the hard-core limit. We show that due to the hidden "lattice" structure of background bosons, the impurity effectively feels a quasi-periodic potential via impurity-boson interactions that can drive the Bloch oscillation under an external force, even in the absence of real lattice potentials. Meanwhile, the inhomogeneous density of trapped bosons imposes an additional harmonic potential to the impurity, resulting in a similar oscillation dynamics but with a different period and amplitude. We show that the sign and strength of the impurity-boson coupling can significantly affect the above two potentials in determining the impurity dynamics.

Emergence of junction dynamics in a strongly interacting Bose mixture

“…Approaching the problem of few atoms in a trap in the strongly interacting regime has also provided knowledge of the fundamental properties of quantum magnetism [30][31][32][33][34][35]. On the other hand, the many-body case in the limit of total population imbalance-the 'impurity' problemalso presents many interesting features, such as quantum flutter [36] and Bloch oscillations in the absence of a lattice [37][38][39][40][41] (the latter having been recently observed in experiments [42]).…”