Quench dynamics of R\'enyi negativities and the quasiparticle picture

TL;DR

This paper investigates the dynamics of Renyi negativities after a quantum quench, combining conformal field theory and integrability to provide a quasiparticle picture that explains entanglement evolution in many-body systems.

Contribution

It introduces a quasiparticle framework for understanding the time evolution of Renyi negativities post-quench, validated by numerical results for free models.

Findings

Quasiparticle picture accurately describes Renyi negativity dynamics.

Analytical predictions match numerical results for free-fermion and free-boson models.

Framework applicable to generic interacting integrable systems.

Abstract

The study of the moments of the partially transposed density matrix provides a new and effective way of detecting bipartite entanglement in a many-body mixed state. This is valuable for cold-atom and ion-trap experiments, as well as in the general context of quantum simulation of many-body systems. In this work we study the time evolution after a quantum quench of the moments of the partial transpose, and several related quantities, such as the R\'enyi negativities. By combining Conformal Field Theory (CFT) results with integrability, we show that, in the space-time scaling limit of long times and large subsystems, a quasiparticle description allows for a complete understanding of the R\'enyi negativities. We test our analytical predictions against exact numerical results for free-fermion and free-boson lattice models, even though our framework applies to generic interacting integrable systems.