Expansion Dynamics of Two Dimensional Extended Bose-Hubbard Model

TL;DR

This paper investigates how extended interactions affect the expansion behavior of ultracold bosons in a 2D lattice, revealing the significant role of nearest neighbor interactions and questioning the contact potential approximation.

Contribution

It provides new insights into the dynamics of extended Bose-Hubbard systems and challenges the common contact potential approximation in the presence of Feshbach resonances.

Findings

Nearest neighbor interactions significantly influence expansion dynamics.

Validity of contact potential approximation is questionable with Feshbach resonances.

Dynamics starting from n=1 Mott state are affected by extended interactions.

Abstract

We study the expansion dynamics of harmonically trapped bosons in a two-dimensional lattice within the extended Bose-Hubbard model. We evaluate the dynamics of the system following a sudden removal of the confining potential, starting with a cloud mostly in n = 1 Mott state. We show that the nearest neighbour interactions have a strong influence on the dynamics of ultracold bosons on an optical lattice. Also we conclude that validity of the widely used contact potential approximation is questionable in the presence of Feschbach resonances.