Dynamics of Disordered States in the Bose-Hubbard Model with Confinement

TL;DR

This paper investigates how the center of mass dynamics in trapped disordered Bose-Hubbard systems can reveal different quantum phases, including the Bose-glass, by analyzing edge state transport mechanisms at zero temperature.

Contribution

It introduces a theoretical framework for understanding edge state transport in disordered Bose-Hubbard models with trapping potentials, highlighting how center of mass motion indicates quantum phase properties.

Findings

Edge states enable center of mass motion despite insulating centers.

Transport mechanisms differ on short and long timescales.

Center of mass velocity can identify the Bose-glass phase.

Abstract

Observations of center of mass dynamics offer a straightforward method to identify strongly interacting quantum phases of atoms placed in optical lattices. We theoretically study the dynamics of states derived from the disordered Bose-Hubbard model in a trapping potential. We find that the edge states in the trap allow center of mass motion even with insulating states in the center. We identify short and long-time scale mechanisms for edge state transport in insulating phases. We also argue that the center of mass velocity can aid in identifying a Bose-glass phase. Our zero temperature results offer important insights into mechanisms of transport of atoms in trapped optical lattices while putting bounds on center of mass dynamics expected at non-zero temperature.