Spreading of entanglement and correlations after a quench with intertwined quasiparticles

TL;DR

This paper extends the semiclassical model for entanglement and correlation spreading after quantum quenches to systems with multiple quasiparticle species and pair correlations, providing explicit predictions and validating them with numerical results.

Contribution

It introduces a generalized semiclassical framework for multiple quasiparticle species with pair correlations and applies it to inhomogeneous lattice models.

Findings

Predicted entanglement spreading in space-time scaling limit.

Derived time evolution of order parameter correlations.

Validated predictions with exact numerical results in the Ising chain.

Abstract

We extend the semiclassical picture for the spreading of entanglement and correlations to quantum quenches with several species of quasiparticles that have non-trivial pair correlations in momentum space. These pair correlations are, for example, relevant in inhomogeneous lattice models with a periodically-modulated Hamiltonian parameter. We provide explicit predictions for the spreading of the entanglement entropy in the space-time scaling limit. We also predict the time evolution of one- and two-point functions of the order parameter for quenches within the ordered phase. We test all our predictions against exact numerical results for quenches in the Ising chain with a modulated transverse field and we find perfect agreement.