Remote Entanglement by Coherent Multiplication of Concurrent Quantum Signals

TL;DR

This paper introduces a novel protocol for remote entanglement of quantum entities using signal multiplication, implemented via a Josephson junction circuit, which is robust against practical imperfections like detector inefficiency and photon loss.

Contribution

It presents a new entanglement protocol based on signal multiplication, differing from traditional addition-based methods, and demonstrates its feasibility with a Josephson junction circuit.

Findings

Protocol can generate entanglement despite detector inefficiencies.

Implementation via Josephson junction mixing circuit is feasible.

Robustness against photon loss demonstrated.

Abstract

Concurrent remote entanglement of distant, non-interacting quantum entities is a crucial function for quantum information processing. In contrast with the existing protocols which employ addition of signals to generate entanglement between two remote qubits, the protocol we present is based on 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 presence of practical imperfections: finite quantum efficiency of detectors and undesired photon loss in current state-of-the-art devices.