Two-particle superposition effects in two-slit interference

TL;DR

This paper investigates how entanglement influences two-particle interference in a two-slit experiment, revealing complex effects and proposing a method to detect multi-particle superpositions, with non-monotonic dependence on entanglement degree.

Contribution

It introduces a novel analysis of multi-particle interference with entangled particles using path integral formalism and suggests a scheme for detecting multi-particle superpositions.

Findings

Entanglement modifies two-particle interference patterns.

The scheme can detect multi-particle superpositions.

Effect depends non-monotonically on entanglement degree.

Abstract

Entanglement can modify the interference patterns of multi-particle systems. We analyse, using the path integral formalism, a novel example of multi-particle interference and some unexplored aspects of this phenomenon by considering the two-slit arrangement with two distinguishable particles in a superposition state. The two components of entanglement, multiplicity of multi-particle terms and their coherence, can be studied separately by comparing the patterns of product, mixed and superposition states. This suggests a scheme to detect multi-particle superposition in some favourable cases. Moreover, the dependence of the effect on the entanglement degree, measured by the Schmidt number, is not a monotone.