Heralded entangled coherent states between spatially separated massive resonators

TL;DR

This paper proposes a feasible scheme to generate heralded entangled coherent states between two distant massive resonators using hybrid quantum devices, beam-splitter interference, and heralding detections, with potential applications in testing gravitational effects on quantum systems.

Contribution

It introduces a novel protocol for entangling massive resonators via hybrid devices and heralded detections, applicable with current circuit QED technology.

Findings

Successful protocol with 50% success probability

Mechanical entanglement verified through qubit entanglement

Potential for testing gravitational effects on quantum dynamics

Abstract

We put forward an experimentally feasible scheme for heralded entanglement generation between two distant macroscopic mechanical resonators. The protocol exploits a hybrid quantum device, a qubit interacting with a mechanical resonator as well as a cavity mode, for each party. The cavity modes interfere on a beam-splitter followed by suitable heralding detections which post-select a hybrid entangled state with success probability 1/2. Subsequently, by local measurements on the qubits a mechanical entangled coherent state can be achieved. The mechanical entanglement can be further verified via monitoring the entanglement of the qubit pair. The setup is envisioned as a test bench for sensing gravitational effects on the quantum dynamics of gravitationally coupled massive objects. As a concrete example, we illustrate the implementation of our protocol using the current circuit QED architectures.