Translation from a Distinguishable to Indistinguishable Two-Photon State

Abstract

Indistinguishability is a crucial element for quantuminterferencein scalable quantum information processing. Here, we demonstrate theability to erase the distinguishability of a nondegenerate two-photonstate using Bragg-scattering four-wave mixing (BS-FWM) by tuning theidler-photon frequency. We achieve a maximum translation efficiencyof 93.2 & PLUSMN; 2.0% and verify the indistinguishability using a Hong-Ou-Mandelinterferometer. The frequency anticorrelation of the input state ispreserved as the two-photon states are translated from the distinguishableto indistinguishable state, as confirmed by the joint spectral intensity.Our results demonstrate precise control of indistinguishability usingBS-FWM, which is a critical step toward large-scale quantum informationprocessing including scalable linear quantum computing and long-distancequantum communications.