Spin readout of nitrogen-vacancy centers with plasmonic nanostructures (Conference Presentation)

Nitrogen-vacancy (NV) color centers in diamond possess electronic spins that one can manipulate coherently at room temperature using RF signals. The optical spin readout plays a key role in their performance for nanoscale magnetometry and quantum information processing. We demonstrate that plasmonic nanostructures can simultaneously guide optical, microwave and low-frequency signals ensuring spin manipulation and readout in an ultracompact setting. They can also enhance detected photon rates through efficient photon collection and shortening of the fluorescence lifetime. We show that in the case of dense NV ensembles the design of the optical readout interface must emphasize photon collection efficiency over Purcell enhancement. However, in the case of single NV centers, large Purcell enhancement may significantly improve the spin readout sensitivity. Enhancement for high-fidelity readout can be provided by nanoparticle-on-metal antennas featuring ultraconfined plasmonic modes.