Quantum Entanglement of Locally Excited States in Maxwell Theory

TL;DR

This paper investigates how local excitations in Maxwell theory affect entanglement entropy, revealing electric-magnetic duality effects and differences from scalar fields, with implications for understanding quantum entanglement in gauge theories.

Contribution

It introduces a study of entanglement entropy changes due to local gauge-invariant operators in Maxwell theory, highlighting duality and late-time behavior.

Findings

Entanglement changes reflect electric-magnetic duality.

Late-time entanglement can be interpreted via electromagnetic quasi-particles.

Operators involving both electric and magnetic fields alter entanglement differently from scalar fields.

Abstract

In 4 dimensional Maxwell gauge theory, we study the changes of (Renyi) entangle-ment entropy which are defined by subtracting the entropy for the ground state from the one for the locally excited states generated by acting with the gauge invariant local operators on the state. The changes for the operators which we consider in this paper reflect the electric-magnetic duality. The late-time value of changes can be interpreted in terms of electromagnetic quasi-particles. When the operator constructed of both electric and magnetic fields acts on the ground state, it shows that the operator acts on the late-time structure of quantum entanglement differently from free scalar fields.