Twist Operator BOPE and Entanglement Entropy in 2D Interface CFT

TL;DR

This paper investigates entanglement entropy in 2D interface CFTs using the replica method, introducing a boundary twist operator via BOPE to compute contributions and compare with holographic results.

Contribution

It introduces a boundary twist operator anchored on the interface and relates its BOPE coefficients to entanglement entropy contributions, extending boundary CFT analysis.

Findings

Derived $O(1)$ entanglement entropy contributions from BOPE coefficients.

Analyzed entanglement entropy for different intervals.

Compared results with previous holographic studies.

Abstract

We address several aspects of entanglement entropy of 2D interface CFT using the replica method. Unlike the case of boundary CFT, we consider the boundary OPE (BOPE) of the R\'enyi twist operator and find a boundary twist operator anchored on the interface. This approach gives the $O(1)$ contribution to the entanglement entropy in terms of the BOPE coefficients of the twist operator. We further analyze entanglement entropy of different intervals and compare our findings with previous holographic results.