How does interference fall?

TL;DR

This paper investigates how quantum interference patterns behave under gravity, demonstrating universality of free fall, exploring relativistic effects with a quantum formalism, and revealing periodic decoherence and recoherence linked to spin-position correlations.

Contribution

It introduces a quantum formalism treating mass as an operator to analyze relativistic effects on interference patterns in a gravitational field, revealing novel decoherence phenomena.

Findings

Interference patterns fall like classical objects under gravity.

Relativistic effects cause periodic decoherence and recoherence in interference visibility.

Spin-position correlations lead to non-Markovian quantum dynamics.

Abstract

We study how single- and double-slit interference patterns fall in the presence of gravity. First, we demonstrate that universality of free fall still holds in this case, i.e., interference patterns fall just like classical objects. Next, we explore lowest order relativistic effects in the Newtonian regime by employing a recent quantum formalism which treats mass as an operator. This leads to interactions between non-degenerate internal degrees of freedom (like spin in an external magnetic field) and external degrees of freedom (like position). Based on these effects, we present an unusual phenomenon, in which a falling double slit interference pattern periodically decoheres and recoheres. The oscillations in the visibility of this interference occur due to correlations built up between spin and position. Finally, we connect the interference visibility revivals with non-Markovian quantum dynamics.