Remote Entanglement by Coherent Multiplication of Concurrent Quantum Signals

Phys Rev Lett. 2015 Oct 9;115(15):150503. doi: 10.1103/PhysRevLett.115.150503. Epub 2015 Oct 9.

Abstract

Concurrent remote entanglement of distant, noninteracting quantum entities is a crucial function for quantum information processing. In contrast with the existing protocols which employ the addition of signals to generate entanglement between two remote qubits, the continuous variable protocol we present is based on the multiplication of signals. This protocol can be straightforwardly implemented by a novel Josephson junction mixing circuit. Our scheme would be able to generate provable entanglement even in the presence of practical imperfections: finite quantum efficiency of detectors and undesired photon loss in current state-of-the-art devices.