Proposal for room-temperature quantum repeaters with nitrogen-vacancy centers and optomechanics

TL;DR

This paper proposes a room-temperature quantum repeater architecture using nitrogen-vacancy centers and optomechanics, enabling long-distance quantum networks with current technology.

Contribution

It introduces a novel quantum repeater design that operates at room temperature, combining NV centers and optomechanics for efficient entanglement and readout.

Findings

Fidelity and efficiency of entanglement quantified.

Entanglement stored in nuclear spins for long distances.

High-fidelity spin readout schemes proposed.

Abstract

We propose a quantum repeater architecture that can operate under ambient conditions. Our proposal builds on recent progress towards non-cryogenic spin-photon interfaces based on nitrogen-vacancy centers, which have excellent spin coherence times even at room temperature, and optomechanics, which allows to avoid phonon-related decoherence and also allows the emitted photons to be in the telecom band. We apply the photon number decomposition method to quantify the fidelity and the efficiency of entanglement established between two remote electron spins. We describe how the entanglement can be stored in nuclear spins and extended to long distances via quasi-deterministic entanglement swapping operations involving the electron and nuclear spins. We furthermore propose schemes to achieve high-fidelity readout of the spin states at room temperature using the spin-optomechanics interface. Our work shows that long-distance quantum networks made of solid-state components that operate at room temperature are within reach of current technological capabilities.