Revisiting self-interference in Young double-slit experiments

TL;DR

This paper investigates self-interference in a Mach-Zehnder interferometer using attenuated laser light in a quantum regime, comparing it with classical interference to support the Born rule and explore quantum superposition.

Contribution

It provides experimental insights into quantum self-interference with attenuated laser light, bridging classical and quantum regimes and supporting fundamental quantum principles.

Findings

Classical and quantum self-interference results are equivalent.

Supports the validity of the Born rule in quantum interference.

Highlights the quantum nature of superposition in bipartite systems.

Abstract

Quantum superposition is the heart of quantum mechanics as mentioned by Dirac and Feynman. In an interferometric system, single photon self-interference has been intensively studied over the last several decades in both quantum and classical regimes. In Born rule tests, the Sorkin parameter indicates the maximum number of possible quantum superposition allowed to the input photons entering an interferometer, where multi-photon interference fringe is equivalent to that of a classical version by a laser. Here, an attenuated laser light in a quantum regime is investigated for self-interference in a Mach-Zehnder interferometer, and the results are compared with its classical version. The resulting equivalent results support the Born rule tests, where the classical interference originates in the superposition of individual single-photon self-interferences. This understanding sheds light on the fundamental physics of quantum features between bipartite systems.