Matter-wave scattering from strongly interacting bosons in an optical lattice

TL;DR

This paper investigates how matter-waves scatter off strongly interacting bosons in an optical lattice, revealing persistent inelastic scattering in the Mott insulator phase and its dependence on interaction strength.

Contribution

It provides analytical expressions for the scattering cross section in the strong-interaction regime and compares them with exact numerical results.

Findings

Inelastic cross section remains non-zero in the Mott insulator phase.

Inelastic scattering decays quadratically with increasing interaction strength.

Analytical results agree with numerical simulations.

Abstract

We study the scattering of a matter-wave from an interacting system of bosons in an optical lattice, focusing on the strong-interaction regime. Analytical expressions for the many-body scattering cross section are derived from a strong-coupling expansion and a site-decoupling mean-field approximation, and compared to numerically obtained exact results. In the thermodynamic limit, we find a non-vanishing inelastic cross section throughout the Mott insulating regime, which decays quadratically as a function of the boson-boson interaction.