Probing dielectric breakdown in Mott insulators through current oscillations

TL;DR

This paper develops a theoretical and experimental framework to understand dielectric breakdown in mesoscopic Mott insulators, using current oscillations to estimate the charge gap and threshold field, with validation through simulations and potential ultracold atomic experiments.

Contribution

It introduces a novel protocol for estimating the charge gap and breakdown threshold via current oscillations, validated by simulations and applicable to ultracold atomic systems.

Findings

Theoretical formula accurately predicts threshold fields for small-gap systems.

Simulation results confirm the validity of the theoretical predictions.

Method is experimentally feasible with existing ultracold atomic technologies.

Abstract

We investigate the dielectric breakdown of mesoscopic Mott insulators, a phenomenon where a strong electric field destabilizes the insulating state, resulting in a transition to a metallic phase. Using the Landau-Zener formalism, which models the excitation of a two-level system, we derive a theoretical expression for the threshold value of the field. To validate our predictions, we present an efficient protocol for estimating the charge gap and threshold field via non-equilibrium current oscillations, overcoming the computational limitations of exact diagonalization. Our simulations demonstrate the accuracy of our theoretical formula for systems with small gaps. Moreover, our findings are directly testable in ultracold atomic experiments with ring geometries and artificial gauge fields, as our method uses measurable quantities and relies on already available technologies. This work aims to bridge the gap between theoretical models and experimentally realizable protocols, providing tools to explore non-equilibrium mesoscopic phenomena in strongly correlated quantum systems.