Critical behavior at the dynamic Mott transition

TL;DR

This paper explores the dynamic Mott transition in a superconducting island array, revealing a current-driven insulator-metal transition with critical behavior similar to liquid-gas transitions, linking equilibrium and nonequilibrium phenomena.

Contribution

It introduces the observation of a vortex Mott insulator and characterizes its critical behavior, providing a quantum mechanical framework for understanding the transition.

Findings

Discovery of vortex Mott insulator in superconducting arrays

Identification of an insulator-to-metal transition driven by electric current

Critical exponents similar to thermodynamic liquid-gas transition

Abstract

We investigate magnetoresistance of a square array of superconducting islands placed on a normal metal, which offers a unique tunable laboratory for realizing and exploring quantum many-body systems and their dynamics. A vortex Mott insulator where magnetic field-induced vortices are frozen in the dimples of the egg crate potential by their strong repulsion interaction is discovered. We find an insulator-to-metal transition driven by the applied electric current and determine critical exponents that exhibit striking similarity with the common thermodynamic liquid-gas transition. A simple and straightforward quantum mechanical picture is proposed that describes both tunneling dynamics in the deep insulating state and the observed scaling behavior in the vicinity of the critical point. Our findings offer a comprehensive description of dynamic Mott critical behavior and establish a deep connection between equilibrium and nonequilibrium phase transitions.