Quantum interferometric visibility as a witness of general relativistic proper time

TL;DR

This paper proposes a novel quantum interferometry effect where the visibility of interference patterns acts as a witness to general relativistic proper time differences, offering a new way to test gravity's influence on quantum systems.

Contribution

It introduces a new quantum effect linking proper time differences to interference visibility, providing a potential experimental test of general relativity in quantum mechanics.

Findings

Visibility decreases with proper time differences due to gravitational effects

Proposes a method to distinguish between phase shifts from potential and proper time

Suggests gravitationally induced decoherence as a test of general relativity in quantum systems

Abstract

Current attempts to probe general relativistic effects in quantum mechanics focus on precision measurements of phase shifts in matter-wave interferometry. Yet, phase shifts can always be explained as arising due to an Aharonov-Bohm effect, where a particle in a flat space-time is subject to an effective potential. Here we propose a novel quantum effect that cannot be explained without the general relativistic notion of proper time. We consider interference of a "clock" - a particle with evolving internal degrees of freedom - that will not only display a phase shift, but also reduce the visibility of the interference pattern. According to general relativity proper time flows at different rates in different regions of space-time. Therefore, due to quantum complementarity the visibility will drop to the extent to which the path information becomes available from reading out the proper time from the "clock". Such a gravitationally induced decoherence would provide the first test of the genuine general relativistic notion of proper time in quantum mechanics.