Experimental storage of photonic polarization entanglement in a broadband cyclical quantum memory

Date

2023-06-16

Department

Program

Citation of Original Publication

Rights

This item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.
Attribution 4.0 International (CC BY 4.0)

Subjects

Abstract

We describe an experiment in which one member of a polarization-entangled photon pair is stored in an active Cyclical Quantum Memory (CQM) device, while the other propagates through a passive optical delay line. A comparison of Bell's inequality tests performed before and after the storage is used to investigate the ability of the CQM to maintain entanglement, and demonstrate a rudimentary entanglement distribution protocol. The entangled photons are produced by a conventional Spontaneous Parametric Down Conversion source with center wavelengths at 780 nm and bandwidths of ∼10 THz, while the CQM has an even wider operational bandwidth that is enabled by the weakly dispersive nature of the Pockels effect used for active switching in a loop-based quantum memory platform.