Cross-entangling electronic and nuclear spins of distant nitrogen-vacancy centers in noisy environments by means of quantum microwave radiation

TL;DR

This paper demonstrates the feasibility of transferring entanglement from quantum microwave radiation to electronic and nuclear spins of distant NV centers in noisy environments, advancing quantum communication potential.

Contribution

It introduces a method for entanglement transfer from microwave photons to NV centers and extends analysis to include nuclear spin baths, considering realistic noise effects.

Findings

Entanglement transfer from microwave photons to NV electron spins is feasible.

The process remains robust under nuclear spin bath dephasing and dissipation.

Potential for entangling remote nuclear spins linked to NV centers is assessed.

Abstract

Nitrogen-vacancy (NV) defect centers in diamond are strong candidates to generate entangled states in solid-state environments even at room temperature. Quantum correlations in spatially separated NV systems, for distances between NVs ranging from a few nanometers to a few kilometers, have been recently reported. In the present work we consider the entanglement transfer from two- mode microwave squeezed (entangled) photons, which are in resonance with the two lowest NV electron spin states, to initially unentangled NV centers. We first demonstrate that the entanglement transfer process from quantum microwaves to isolated NV electron spins is feasible. We then proceed to extend the previous results to more realistic scenarios where 13 C nuclear spin baths surrounding each NV are included, quantifying the entanglement transfer efficiency and robustness under the effects of dephasing/dissipation noisy nuclear baths. Finally, we address the issue of assessing the possibility of entanglement transfer from the squeezed microwave light to two remote nuclear spins closely linked to different NV centers.