The entanglement entropy of one-dimensional gases

TL;DR

This paper presents a systematic method for calculating the bipartite entanglement entropy in one-dimensional quantum gases, applicable to various boundary conditions, potentials, and time-dependent scenarios.

Contribution

The authors develop a general framework for entanglement entropy calculation in 1D gases mapped to noninteracting fermions, covering diverse physical setups.

Findings

Applicable to periodic, boundary-confined, and junction systems

Handles time-dependent potentials

Demonstrates wide applicability of the formalism

Abstract

We introduce a systematic framework to calculate the bipartite entanglement entropy of a spatial subsystem in a one-dimensional quantum gas which can be mapped into a noninteracting fermion system. To show the wide range of applicability of the proposed formalism, we use it for the calculation of the entanglement in the eigenstates of periodic systems, in a gas confined by boundaries or external potentials, in junctions of quantum wires and in a time-dependent parabolic potential.