One-particle entanglement for one dimensional spinless fermions after an interaction quantum quench

TL;DR

This paper investigates the dynamics of one-particle entanglement entropy in a one-dimensional spinless fermion model after an interaction quench, combining numerical methods and field theory comparisons.

Contribution

It provides a detailed numerical study of post-quench entanglement and momentum distribution in an integrable fermionic model, connecting with bosonization predictions.

Findings

Numerical results agree with bosonization in the thermodynamic limit.

Post-quench momentum distribution exhibits characteristic time evolution.

Interaction cutoff can be uniquely determined from ground state properties.

Abstract

Particle entanglement provides information on quantum correlations in systems of indistinguishable particles. Here, we study the one particle entanglement entropy for an integrable model of spinless, interacting fermions both at equilibrium and after an interaction quantum quench. Using both large scale exact diagonalization and time dependent density matrix renormalization group calculations, we numerically compute the one body reduced density matrix for the J-V model, as well as its post-quench dynamics. We include an analysis of the fermionic momentum distribution, showcasing its time evolution after a quantum quench. Our numerical results, extrapolated to the thermodynamic limit, can be compared with field theoretic bosonization in the Tomonaga-Luttinger liquid regime. Excellent agreement is obtained using an interaction cutoff that can be determined uniquely in the ground state.