Nanophotonics for quantum optics using nitrogen-vacancy centers in diamond

Abstract

Optical microcavities and waveguides coupled to diamond are needed to enable efficientcommunication between quantum systems such as nitrogen-vacancy centers which areknown already to have long electron spin coherence lifetimes. This paper describes recentprogress in realizing microcavities with low loss and small mode volume in twohybrid systems: silica microdisks coupled to diamond nanoparticles, and galliumphosphide microdisks coupled to single-crystal diamond. A theoretical proposal for agallium phosphide nanowire photonic crystal cavity coupled to diamond is alsodiscussed. Comparing the two material systems, silica microdisks are easier tofabricate and test. However, at low temperature, nitrogen-vacancy centers in bulkdiamond are spectrally more stable, and we expect that in the long term the bulkdiamond approach will be better suited for on-chip integration of a photonicnetwork.