Black holes as mirrors: quantum information in random subsystems

TL;DR

This paper models black hole information retrieval using quantum error correction and rapid mixing dynamics, showing that information is rapidly released after the halfway point of evaporation, aligning with black hole complementarity.

Contribution

It introduces a framework connecting black hole evaporation, quantum error correction, and rapid information release, providing new insights into black hole information paradox.

Findings

Information is revealed rapidly after the halfway point of evaporation.

Typical local quantum circuits encode information efficiently for quantum error correction.

Black hole retention time estimates are compatible with black hole complementarity.

Abstract

We study information retrieval from evaporating black holes, assuming that the internal dynamics of a black hole is unitary and rapidly mixing, and assuming that the retriever has unlimited control over the emitted Hawking radiation. If the evaporation of the black hole has already proceeded past the "half-way" point, where half of the initial entropy has been radiated away, then additional quantum information deposited in the black hole is revealed in the Hawking radiation very rapidly. Information deposited prior to the half-way point remains concealed until the half-way point, and then emerges quickly. These conclusions hold because typical local quantum circuits are efficient encoders for quantum error-correcting codes that nearly achieve the capacity of the quantum erasure channel. Our estimate of a black hole's information retention time, based on speculative dynamical assumptions, is just barely compatible with the black hole complementarity hypothesis.