Time-bin entangled photon holes

TL;DR

This paper introduces the concept of time-bin entangled photon holes, demonstrating their creation, properties, and equivalence to photon-pair states, with experimental validation via Bell inequality violation.

Contribution

It presents the first experimental realization of time-bin entangled photon holes and shows their equivalence to entangled photon pairs under certain conditions.

Findings

Successfully generated time-bin entangled photon holes

Demonstrated Bell inequality violation with these states

Established equivalence to photon-pair entangled states

Abstract

The general concept of entangled photon holes is based on a correlated absence of photon pairs in an otherwise constant optical background. Here we consider the specialized case when this background is confined to two well-defined time bins, which allows the formation of time-bin entangled photon holes. We show that when the typical coherent state background is replaced by a true single-photon (Fock state) background, the basic time-bin entangled photon-hole state becomes equivalent to one of the time-bin entangled photon-pair states. We experimentally demonstrate these ideas using a parametric down-conversion photon-pair source, linear optics, and post-selection to violate a Bell inequality with time-bin entangled photon holes.