Two-boson quantum interference in time

TL;DR

This paper reveals a new two-boson interference effect in quantum amplifiers, extending the understanding of bosonic symmetry and indistinguishability beyond traditional beam splitter experiments, with broad implications for quantum physics.

Contribution

It introduces a novel two-boson interference phenomenon in quantum amplifiers via a partial time reversal symmetry, expanding the scope of bosonic interference effects.

Findings

Discovered a two-boson interferometric effect in quantum amplifiers.

Linked the effect to timelike indistinguishability and bosonic Bogoliubov transformations.

Established a duality between beam splitter coupling and amplification.

Abstract

The celebrated Hong-Ou-Mandel effect is the paradigm of two-particle quantum interference. It has its roots in the symmetry of identical quantum particles, as dictated by the Pauli principle. Two identical bosons impinging on a beam splitter (of transmittance 1/2) cannot be detected in coincidence at both output ports, as confirmed in numerous experiments with light or even matter. Here, we establish that partial time reversal transforms the beamsplitter linear coupling into amplification. We infer from this duality the existence of an unsuspected two-boson interferometric effect in a quantum amplifier (of gain 2) and identify the underlying mechanism as timelike indistinguishability. This fundamental mechanism is generic to any bosonic Bogoliubov transformation, so we anticipate wide implications in quantum physics.