Information Erasure and the Generalized Second Law of Black Hole Thermodynamics

TL;DR

This paper links quantum information theory with black hole thermodynamics, demonstrating that information erasure and Landauer's principle support the generalized second law in a quantum black hole context.

Contribution

It provides a simple proof of the generalized second law using quantum relative entropy and confirms it through the analysis of information erasure and Landauer's principle.

Findings

Quantum relative entropy proves the generalized second law.

Information erasure aligns with entropy increase in black hole scenarios.

Landauer's principle supports the thermodynamic consistency of black hole information processes.

Abstract

We consider the generalized second law of black hole thermodynamics in the light of quantum information theory, in particular information erasure and Landauer's principle (namely, that erasure of information produces at least the equivalent amount of entropy). A small quantum system outside a black hole in the Hartle-Hawking state is studied, and the quantum system comes into thermal equilibrium with the radiation surrounding the black hole. For this scenario, we present a simple proof of the generalized second law based on quantum relative entropy. We then analyze the corresponding information erasure process, and confirm our proof of the generalized second law by applying Landauer's principle.