Dispersion cancellation in a quantum interferometer with independent single photons

TL;DR

This paper demonstrates both theoretically and experimentally that group velocity dispersion effects on two-photon interference can be canceled when two independent photons experience identical pulse broadening, enhancing quantum interference quality.

Contribution

It introduces a method to cancel dispersion effects in multi-photon quantum interferometers, improving quantum information processing techniques.

Findings

Dispersion cancellation occurs when two photons undergo equal pulse broadening.

Experimental validation confirms theoretical predictions.

Applicable to multi-path interferometers in quantum communication and computing.

Abstract

A key technique to perform a proper quantum information processing is to get a high visibility quantum interference between independent single photons. One of the crucial elements that affects the quantum interference is a group velocity dispersion that occurs when the single photons pass through a dispersive medium. We theoretically and experimentally demonstrate that an effect of group velocity dispersion on the two-photon interference can be cancelled if two independent single photons experience the same amount of pulse broadening. This dispersion cancellation effect can be generalized to a multi-path linear interferometer with multiple independent single photons. As multi-path quantum interferometers are at the heart of quantum communication, photonic quantum computing, and boson sampling applications, our work should find wide applicability in quantum information science.