Entanglement in a periodic quench

TL;DR

This paper investigates how entanglement entropy evolves in a periodically driven free electron chain, revealing stepwise growth, oscillations, and explicit solutions for specific parameters, with connections to equilibrium models.

Contribution

It provides a detailed analysis of entanglement dynamics under periodic quenches and offers explicit solutions for certain cases, advancing understanding of non-equilibrium quantum systems.

Findings

Entanglement entropy grows stepwise towards a segment-length proportional value.

Entanglement exhibits slow oscillations during evolution.

Explicit solutions are derived for specific quench periods and full dimerization.

Abstract

We consider a chain of free electrons with periodically switched dimerization and study the entanglement entropy of a segment with the remainder of the system. We show that it evolves in a stepwise manner towards a value proportional to the length of the segment and displays in general slow oscillations. For particular quench periods and full dimerization an explicit solution is given. Relations to equilibrium lattice models are pointed out.