The origin of indistinguishability of quantum features in an interferometric system

TL;DR

This paper challenges traditional views by proposing that a strong mutual phase dependency, rather than indistinguishability alone, is fundamental to photon bunching in interferometric systems, supported by a coherent model analysis.

Contribution

It introduces a new perspective that phase relationships are essential for quantum features, extending the analysis to a Mach-Zehnder interferometer with a coherent model.

Findings

Photon bunching depends on mutual phase relationships.

Phase-basis superposition explains quantum indistinguishability.

Extended scheme validates phase dependency in interferometric systems.

Abstract

One of the most fundamental quantum features is the two-photon intensity correlation on a beam splitter, resulting in photon bunching into either output port. According to the conventional understanding of quantum mechanics, the origin of photon bunching on a beam splitter is in the indistinguishable characteristics between coincident photons, resulting in destructive quantum interference even without a clear definition of phase information of the paired photons. Here, a completely different approach is presented for the same quantum feature, where a strong mutual phase dependency is the essential requirement for the nonclassical feature of photon bunching. This definite phase relationship is now understood as the origin of this quantum feature resulting from the phase-basis superposition of the photon-BS system, resulting in photon indistinguishability. On behalf of a coherent model with a single input-port BS system, an extended scheme of a Mach-Zehnder interferometer is additionally analyzed for the validity of forbidden phase-basis superposition in the quantum feature.