Observation of Young's Double-Slit Interference with the Three-Photon N00N State

TL;DR

This paper reports the first experimental observation of three-photon N00N state interference, demonstrating super-resolved spatial quantum interference with potential applications in quantum lithography and imaging.

Contribution

It is the first to experimentally observe three-photon N00N state spatial interference, advancing quantum entanglement applications in super-resolution imaging.

Findings

Three-photon N00N state produces three times denser interference fringes.

Interference visibility of 0.49 exceeds classical super-resolution limit.

Demonstrates spatial quantum interference with more than two photons.

Abstract

Spatial interference of quantum mechanical particles exhibits a fundamental feature of quantum mechanics. A two-mode entangled state of N particles known as N00N state can give rise to non-classical interference. We report the first experimental observation of a three-photon N00N state exhibiting Young's double-slit type spatial quantum interference. Compared to a single-photon state, the three-photon entangled state generates interference fringes that are three times denser. Moreover, its interference visibility of $0.49 \pm 0.09$ is well above the limit of 0.1 for spatial super-resolution of classical origin. The demonstration of spatial quantum interference by a N00N state composed of more than two photons represents an important step towards applying quantum entanglement to technologies such as lithography and imaging.