Highly Retrievable Spinwave-Photon Entanglement Source

TL;DR

This paper presents a highly efficient spinwave-photon entanglement source with a 76% retrieval efficiency, advancing quantum repeater and network technologies by enabling more scalable quantum communication.

Contribution

The authors develop a novel entanglement source with a resonant cavity design that significantly improves retrieval efficiency compared to previous methods.

Findings

Achieved intrinsic retrieval efficiency of 76(4)%

Created polarization entanglement via atom-photon interaction

Enabled efficient retrieval of spinwave qubits

Abstract

Entanglement between a single photon and a quantum memory forms the building blocks for quantum repeater and quantum network. Previous entanglement sources are typically with low retrieval efficiency, which limits future larger-scale applications. Here, we report a source of highly retrievable spinwave-photon entanglement. Polarization entanglement is created through interaction of a single photon with ensemble of atoms inside a low-finesse ring cavity. The cavity is engineered to be resonant for dual spinwave modes, which thus enables efficient retrieval of the spinwave qubit. An intrinsic retrieval efficiency up to 76(4)% has been observed. Such a highly retrievable atom-photon entanglement source will be very useful in future larger-scale quantum repeater and quantum network applications.