The colored Hanbury Brown--Twiss effect

TL;DR

This paper introduces a generalized Hanbury Brown--Twiss effect that incorporates photon frequency, revealing that photons of different colors tend to avoid each other, and suggesting fermions could exhibit boson-like correlations through frequency filtering.

Contribution

The study presents a novel experimental technique to include photon frequency in the Hanbury Brown--Twiss effect, expanding understanding of photon correlations based on color and energy.

Findings

Photons of different colors tend to avoid each other.

A generalized effect includes photon frequency, revealing new correlation behaviors.

Fermions might exhibit boson-like correlations via frequency filtering.

Abstract

The Hanbury Brown--Twiss effect is one of the celebrated phenomenologies of modern physics that accommodates equally well classical (interferences of waves) and quantum (correlations between indistinguishable particles) interpretations. The effect was discovered in the late thirties with a basic observation of Hanbury Brown that radio-pulses from two distinct antennas generate signals on the oscilloscope that wiggle similarly to the naked eye. When Hanbury Brown and his mathematician colleague Twiss took the obvious step to propose bringing the effect in the optical range, they met with considerable opposition as single-photon interferences were deemed impossible. The Hanbury Brown--Twiss effect is nowadays universally accepted and, being so fundamental, embodies many subtleties of our understanding of the wave/particle dual nature of light. Thanks to a novel experimental technique, we report here a generalized version of the Hanbury Brown--Twiss effect to include the frequency of the detected light, or, from the particle point of view, the energy of the detected photons. In addition to the known tendencies of indistinguishable photons to arrive together on the detector, we find that photons of different colors present the opposite characteristic of avoiding each others. We postulate that fermions can be similarly brought to exhibit positive (boson-like) correlations by frequency filtering.