Mott transition in a cavity-boson system: A quantitative comparison between theory and experiment

TL;DR

This paper presents a quantitative comparison between experimental measurements and theoretical simulations of the Mott transition in a cavity-boson system, demonstrating a new approach for accurately determining phase boundaries.

Contribution

It introduces a novel numerical method using a two-dimensional four-well potential to accurately simulate the phase transition in cavity-boson systems.

Findings

Experimental and theoretical phase boundaries agree reasonably.

The chosen representation induces small systematic errors.

The method provides a new way to determine phase boundaries quantitatively.

Abstract

The competition between short-range and cavity-mediated infinite-range interactions in a cavity-boson system leads to the existence of a superfluid phase and a Mott-insulator phase within the self-organized regime. In this work, we quantitatively compare the steady-state phase boundaries of this transition measured in experiments and simulated using the Multiconfigurational Time-Dependent Hartree Method for Indistinguishable Particles. To make the problem computationally feasible, we represent the full system by the exact many-body wave function of a two-dimensional four-well potential. We argue that the validity of this representation comes from the nature of both the cavity-atomic system and the Bose-Hubbard physics. Additionally we show that the chosen representation only induces small systematic errors, and that the experimentally measured and theoretically predicted phase boundaries agree reasonably. We thus demonstrate a new approach for the quantitative numerical determination of the superfluid--Mott-insulator phase boundary.