Mott insulator breakdown through pattern formation

TL;DR

This paper investigates how a Mott insulator breaks down under an applied bias voltage, revealing a phase diagram with spatial patterns and mid-gap states that influence conductance.

Contribution

It introduces a novel non-equilibrium phase diagram showing pattern formation and mid-gap states during Mott insulator breakdown under bias voltage.

Findings

Pattern formation occurs below the equilibrium Mott gap.

Mid-gap states emerge, enabling finite conductance.

Spatial charge gap patterns are identified.

Abstract

We study the breakdown of a Mott insulator with the thermodynamic imbalance induced by an applied bias voltage. By analyzing the instabilities of the magnetic susceptibility, we describe a rich non-equilibrium phase diagram, obtained for different applied voltages, that exhibits phases with a spatially patterned charge gap. For a finite voltage, smaller than the value of the equilibrium Mott gap, the formation of patterns coincides with the emergence of mid-gap states contributing to a finite steady-state conductance. We discuss the experimental implications of this new scenario of Mott breakdown.