General relativistic effects in quantum interference of photons

TL;DR

This paper proposes a quantum interference experiment with single photons in curved space-time to test the interplay between quantum mechanics and general relativity, predicting observable effects on interference visibility due to gravitational time dilation.

Contribution

It introduces a novel experimental setup to probe quantum effects in curved space-time, bridging a gap between quantum mechanics and general relativity testing.

Findings

Interference visibility drops when gravitational time dilation exceeds photon coherence time

Shorter time dilations cause only phase shifts, not visibility loss

Feasibility analysis suggests potential for experimental realization

Abstract

Quantum mechanics and general relativity have been extensively and independently confirmed in many experiments. However, the interplay of the two theories has never been tested: all experiments that measured the influence of gravity on quantum systems are consistent with non-relativistic, Newtonian gravity. On the other hand, all tests of general relativity can be described within the framework of classical physics. Here we discuss a quantum interference experiment with single photons that can probe quantum mechanics in curved space-time. We consider a single photon travelling in superposition along two paths in an interferometer, with each arm experiencing a different gravitational time dilation. If the difference in the time dilations is comparable with the photon's coherence time, the visibility of the quantum interference is predicted to drop, while for shorter time dilations the effect of gravity will result only in a relative phase shift between the two arms. We discuss what aspects of the interplay between quantum mechanics and general relativity are probed in such experiments and analyze the experimental feasibility.