Structured position-momentum entangled two-photon fields

TL;DR

This paper reports the experimental generation of structured two-photon fields with position-momentum entanglement, advancing quantum imaging and sensing capabilities by combining spatial structuring with entanglement.

Contribution

It demonstrates a method to produce structured, position-momentum entangled two-photon fields via phase-matching manipulation in spontaneous parametric down-conversion.

Findings

Successfully generated structured entangled two-photon fields.

Measured the minimum entanglement of formation.

Verified position-momentum entanglement in structured fields.

Abstract

Structured optical fields have led to several ground-breaking techniques in classical imaging and microscopy. At the same time, in the quantum domain, position-momentum entangled photon fields have been shown to have several unique features that can lead to beyond-classical imaging and microscopy capabilities. Therefore, it is natural to expect that position-momentum entangled two-photon fields that are structured can push the boundaries of quantum imaging and microscopy even further beyond. Nonetheless, the existing experimental schemes are able to produce either structured two-photon fields without position-momentum entanglement, or position-momentum entangled two-photon fields without structures. In this article, by manipulating the phase-matching condition of the spontaneous parametric down-conversion process, we report experimental generation of two-photon fields with various structures in their spatial correlations. We experimentally measure the minimum bound on the entanglement of formation and thereby verify the position-momentum entanglement of the structured two-photon field. We expect this work to have important implications for quantum technologies related to imaging and sensing.