Defect production in nonequilibrium phase transitions: Experimental investigation of the Kibble-Zurek mechanism in a two-qubit quantum simulator

TL;DR

This paper experimentally investigates the Kibble-Zurek mechanism in a two-qubit quantum simulator, confirming its role in defect formation during non-equilibrium quantum phase transitions.

Contribution

It provides the first experimental validation of the Kibble-Zurek mechanism in a controlled quantum system using nuclear spins.

Findings

Experimental data supports the Kibble-Zurek mechanism.

Defect formation scales with quench rate as predicted.

Quantum simulator accurately models non-equilibrium phase transitions.

Abstract

Systems passing through quantum critical points at finite rates have a finite probability of undergoing transitions between different eigenstates of the instantaneous Hamiltonian. This mechanism was proposed by Kibble as the underlying mechanism for the formation of topological defects in the early universe and by Zurek for condensed matter systems. Here, we use a system of nuclear spins as an experimental quantum simulator undergoing a non-equilibrium quantum phase transition. The experimental data confirm the validity of the Kibble-Zurek mechanism of defect formation.