Revealing Bosonic Exchange Symmetry in Two-Photon Temporal Wavefunction

TL;DR

This paper experimentally demonstrates the bosonic exchange symmetry in the temporal wavefunction of photon pairs, confirming a fundamental quantum principle through direct measurement of correlations and interference.

Contribution

It provides the first direct experimental observation of bosonic exchange symmetry in the time domain using photon pairs from cold atomic ensembles.

Findings

Measured two-photon correlations match theoretical predictions.

Reconstructed complex temporal wavefunction shows symmetry under exchange.

Confirmed bosonic symmetry in the time domain through interference.

Abstract

The wavefunction of two identical bosons remains invariant under particle exchange - a fundamental quantum symmetry that underlies Bose-Einstein statistics. We report the direct experimental observation of bosonic exchange symmetry in the temporal wavefunction of photon pairs generated via spontaneous four-wave mixing in a three-level cold atomic ensemble. The measured two-photon temporal correlations show excellent agreement with theoretical predictions based on symmetrized bosonic wavefunctions. In addition, we perform time-resolved two-photon interference to reconstruct the complex temporal wavefunction. Both the amplitude and phase profiles exhibit clear symmetry under photon exchange, providing a direct confirmation of bosonic exchange symmetry in the time domain.