Bridging global and local quantum quenches in conformal field theories

TL;DR

This paper analytically bridges global and local quantum quenches in 1+1D conformal field theories by studying entanglement evolution from an inhomogeneous initial state, revealing features of both quench types over different time scales.

Contribution

It introduces a unified setup for studying global and local quenches in CFTs using conformal mappings, providing analytical solutions and physical insights.

Findings

Entanglement shows global quench behavior at short times.

Entanglement exhibits local quench features at long times.

Single-point correlation functions reflect the same transition.

Abstract

Entanglement evolutions after a global quantum quench and a local quantum quench in 1+1 dimensional conformal field theories (CFTs) show qualitatively different behaviors, and are studied within two different setups. In this work, we bridge global and local quantum quenches in (1+1)-d CFTs in the same setup, by studying the entanglement evolution from a specific inhomogeneous initial state. By utilizing conformal mappings, this inhomogeneous quantum quench is analytically solvable. It is found that the entanglement evolution shows a global quantum quench feature in the short time limit, and a local quantum quench feature in the long time limit. The same features are observed in single-point correlation functions of primary fields. We provide a clear physical picture for the underlying reason.