Stability of the Mott phase in excitonic double layers

TL;DR

This paper investigates the stability of excitonic Mott phases in double-layer systems, using a hybrid theoretical approach to map out phase transitions relevant to recent experimental observations.

Contribution

It introduces a combined mean-field and hopping expansion method to analyze the stability of Mott phases under non-local interactions and periodic potentials.

Findings

Established a phase diagram for Mott to superfluid transition.

Identified criteria for Mott phase stability against fluctuations.

Provided insights applicable to electron-hole crystal experiments.

Abstract

We study the stability of excitonic Mott phases in the presence of a periodic potential and a non-local exciton-exciton interaction. The non-local interaction is treated in a mean-field approximation, while the local repulsion of the excitons is treated in a hopping expansion. The convergence of the latter is the criterion for the stability of the Mott phase with respect to quantum and thermal fluctuations. This hybrid approach enables us to establish a phase diagram for a bosonic Mott to superfluid transition. Our results could be useful to interpret recent experiments on electron-hole crystals in van der Waals heterostructures.