Diamond Nanomechanical Resonators with Narrow Linewidth NVs

Nitrogen vacancy centers in diamond are promising qubit candidates which have had recent work focusing on interfacing NVs with acoustic fields. One approach, which is monolithic and doesn’t require external driving of phonons, is coupling NVs to high quality factor mechanical resonators in diamond. This approach necessitates low mass, thin membranes which are generally fabricated by thinning down a thicker diamond sample with a plasma etch. However, plasma damage to the diamond results in deep charge defects and poor surface termination which affects the spin and optical properties of the NV center. Here we report on the fabrication of thin mechanical resonators imbedded in a phononic crystal and the measurement of improved optical properties of NVs in those membranes.