Variation of Entanglement Entropy in Scattering Process

TL;DR

This paper investigates how entanglement entropy varies during two-particle scattering processes, analyzing changes from initial to final states in quantum mechanics and field theory.

Contribution

It provides a perturbative calculation of entanglement entropy change in scattering, considering both initially entangled and unentangled states, with examples in field theory and quantum mechanics.

Findings

Entanglement entropy changes depend on initial state entanglement.

Perturbative methods effectively quantify entropy variation in scattering.

Examples demonstrate the theoretical framework in practical scenarios.

Abstract

In a scattering process, the final state is determined by an initial state and an S-matrix. We focus on two-particle scattering processes and consider the entanglement between these particles. For two types initial states; i.e., an unentangled state and an entangled one, we calculate perturbatively the change of entanglement entropy from the initial state to the final one. Then we show a few examples in a field theory and in quantum mechanics.