Momentum space entanglement of four fermion field theory

TL;DR

This paper calculates the momentum space entanglement in four fermion field theory using a perturbative Wilsonian effective action, revealing nonlocal terms as the key source of entanglement and introducing new Feynman rules for diagram interpretation.

Contribution

It introduces a perturbative method to compute momentum space entanglement in four fermion theories and proposes new Feynman rules for diagrammatic analysis.

Findings

Local terms are perturbatively non-relevant in low energy effective action.

Nonlocal terms are the primary source of momentum space entanglement.

Basketball Feynman diagrams effectively represent the entanglement calculations.

Abstract

Momentum space entanglement of four fermion field theory is calculated from the Wilsonian effective action pertubatively using replica trick, local terms in low energy effective action are proved to be non-relevant pertubatively and nonlocal terms are the only source of entanglement between different momentum modes. The final result again can be represented by a set of basketball feynmann diagrams with new feynmann rules proposed to inteprete them.