Localized detection of quantum entanglement through the event horizon

TL;DR

This paper introduces a localized approach to understanding how quantum entanglement degrades for accelerated observers, highlighting mode mismatch and horizon effects as key factors, with implications for quantum information in relativistic settings.

Contribution

It provides a localized detection model that isolates the effects of mode mismatch and horizon leakage on entanglement degradation in non-inertial frames.

Findings

Unruh vacuum noise has minimal impact on entanglement degradation.

Mode mismatch is the primary cause of entanglement loss.

Horizon leakage imposes fundamental limits on entanglement measurement.

Abstract

We present a completely localized solution to the problem of entanglement degradation in non-inertial frames. A two mode squeezed state is considered from the viewpoint of two observers, Alice (inertial) and Rob (accelerated), and a model of localized projective detection is used to study the amount of entanglement that they are able to extract from the initial state. The Unruh vacuum noise plays only a minor role in the degradation process. The dominant source of degradation is a mode mismatch between the mode of the squeezed state Rob observes and the mode he is able to detect from his accelerated frame. Leakage of the initial mode through Rob's horizon places a limit on his ability to fully measure the state, leading to an inevitable degradation of entanglement that even in principle cannot be corrected by changing the hardware design of his detector.