Experimental control of remote spatial indistinguishability of photons to realize entanglement and teleportation

TL;DR

This paper demonstrates how remote control of photon indistinguishability can generate entanglement and enable quantum teleportation, highlighting a new way to manipulate quantum resources at a distance.

Contribution

It introduces an experimental setup that tunes the spatial indistinguishability of photons to produce entanglement and perform teleportation, a novel approach in quantum information processing.

Findings

Entanglement depends on the degree of spatial indistinguishability.

Teleportation fidelities exceed the classical threshold.

A basic nonlocal entangling gate was realized.

Abstract

Remote spatial indistinguishability of identical subsystems as a direct controllable quantum resource at distant sites has not been yet experimentally proven. We design a setup capable to tune the spatial indistinguishability of two photons by independently adjusting their spatial distribution in two distant regions, which leads to polarization entanglement starting from uncorrelated photons. The amount of entanglement uniquely depends on the degree of remote spatial indistinguishability, quantified by an entropic measure $\mathcal{I}$, which enables teleportation with fidelities above the classical threshold. This experiment realizes a basic nonlocal entangling gate by the inherent nature of identical quantum subsystems.