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

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, and works also in the weak coupling regime. We consider potential experimental realizations using single atom, colour centre and quantum dot cavity systems. Finally our scheme appears to be promising for implementing quantum information protocols based on non-locality. Here we discuss a possible implementation of device-independent quantum key distribution.