Proposal for a loophole-free Bell test based on spin-photon interactions in cavities

TL;DR

This paper proposes a scheme for a loophole-free Bell test using spin-photon interactions in cavities, enabling robust quantum nonlocality demonstrations suitable for secure quantum communication.

Contribution

It introduces a heralded entanglement transfer method from photons to solid-state spins via cavity QED, enhancing robustness against channel losses.

Findings

Scheme is insensitive to channel losses due to heralded transfer

Potential experimental implementations with atoms, color centers, and quantum dots

Facilitates device-independent quantum key distribution

Abstract

We present a scheme to demonstrate loophole-free Bell inequality violation where the entanglement between photon pairs is transferred to solid state (spin) qubits mediated by cavity QED interactions. As this transfer can be achieved in a heralded way, our scheme is basically insensitive to losses on the channel. This makes it appealing for the implementation of quantum information protocols based on nonlocality, such as device-independent quantum key distribution. We consider potential experimental realisations of our scheme using single atom, colour centre and quantum dot cavity systems.