Anomalous universal adiabatic dynamics: The case of the Fredkin model

TL;DR

This paper investigates a universal scaling law for defect production during quantum phase transitions, revealing a breakdown of the Kibble-Zurek mechanism in the deformed Fredkin spin chain.

Contribution

It introduces a new universal scaling law for defect formation that differs from Kibble-Zurek, demonstrated through the deformed Fredkin model.

Findings

Discovery of a new universal defect scaling law

Demonstration of Kibble-Zurek breakdown in a specific quantum model

Analysis of critical exponents' role in defect dynamics

Abstract

When a system is driven across a second-order quantum phase transition, the number of defects which are produced scales with the speed of the variation of the tuning parameter according to a universal law described by the Kibble-Zurek mechanism. We study a possible breakdown of this prediction proving that the number of defects can exhibit another universal scaling law which is still related only to the critical exponents $z$ and $\nu$, but differs from the Kibble-Zurek result. Finally we provide an example, the deformed Fredkin spin chain, where this violation of the standard adiabatic dynamics can occur.