Dynamical quantum phase transitions in spin-$S$ $\mathrm{U}(1)$ quantum link models

TL;DR

This paper investigates dynamical quantum phase transitions in spin-$S$ $ ext{U}(1)$ quantum link models using matrix product states, revealing diverse types of DQPTs beyond traditional order parameter sign changes.

Contribution

It demonstrates that DQPTs in quantum link models are more varied than previously understood, especially for $S>1/2$, and differ from the Wilson--Kogut--Susskind limit.

Findings

Diverse types of DQPTs identified beyond order parameter sign change

DQPTs differ significantly between $S=1/2$ and higher spin cases

Quantum link formalism captures different DQPT behavior than Wilson--Kogut--Susskind limit

Abstract

Dynamical quantum phase transitions (DQPTs) are a powerful concept of probing far-from-equilibrium criticality in quantum many-body systems. With the strong ongoing experimental drive to quantum-simulate lattice gauge theories, it becomes important to investigate DQPTs in these models in order to better understand their far-from-equilibrium properties. In this work, we use infinite matrix product state techniques to study DQPTs in spin-$S$ $\mathrm{U}(1)$ quantum link models. Although we are able to reproduce literature results directly connecting DQPTs to a sign change in the dynamical order parameter in the case of $S=1/2$ for quenches starting in a vacuum initial state, we find that for different quench protocols or different values of the link spin length $S>1/2$ this direct connection is no longer present. In particular, we find that there is an abundance of different types of DQPTs not directly associated with any sign change of the order parameter. Our findings indicate that DQPTs are fundamentally different between the Wilson--Kogut--Susskind limit and its representation through the quantum link formalism.