Measurement-Induced Long-Distance Entanglement of Superconducting Qubits using Optomechanical Transducers

TL;DR

This paper proposes a method to generate long-distance entanglement between superconducting qubits using optomechanical transducers, enabling quantum networking despite the challenge of interfacing superconducting systems with light.

Contribution

It introduces a measurement-based entanglement scheme mediated by mechanical oscillators that does not require ground-state cooling and tolerates transmission loss, advancing superconducting quantum networks.

Findings

Entanglement can be generated without ground-state cooling.

The setup tolerates substantial transmission loss.

Scalable to multipartite entanglement.

Abstract

Although superconducting systems provide a promising platform for quantum computing, their networking poses a challenge as they cannot be interfaced to light---the medium used to send quantum signals through channels at room temperature. We show that mechanical oscillators can mediated such coupling and light can be used to measure the joint state of two distant qubits. The measurement provides information on the total spin of the two qubits such that entangled qubit states can be postselected. Entanglement generation is possible without ground-state cooling of the mechanical oscillators for systems with optomechanical cooperativity moderately larger than unity; in addition, our setup tolerates a substantial transmission loss. The approach is scalable to generation of multipartite entanglement and represents a crucial step towards quantum networks with superconducting circuits.