Phonon instability of insulating states in optical lattices

TL;DR

This paper investigates how collective phonon excitations caused by intersite atomic interactions can destabilize insulating states in optical lattices, leading to atom delocalization.

Contribution

It reveals that phonon excitations can significantly reduce atom localization, causing insulating states to become delocalized, regardless of interaction range.

Findings

Phonon excitations weaken atom localization in optical lattices.

Insulating states can become delocalized due to phonon effects.

Delocalization occurs for both long-range and local interactions.

Abstract

The influence of collective phonon excitations, due to intersite atomic interactions, on the stability of optical lattices is analyzed. These phonon excitations are shown to essentially reduce the ability of atoms to be localized. The states that seem to be insulating in the absence of the phonon excitations can become delocalized when the latter are present. The delocalization effect exists for both long-range as well as local atomic interactions.