Controlling Nitrogen-Vacancy Center Spins with a Mechanical Resonator

Abstract

The spin state of the nitrogen-vacancy (NV) center in diamond offers a promising platform for the development of quantum technologies and investigations into spin dynamics at the nanoscale. With a lengthy coherence time even at room temperature, NV centers enable precision metrology with atomic scale spatial resolution and present one path towards quantum information in the solid state. These applications require coherent control of the NV center spin state, and this can be achieved with resonant magnetic fields, electric fields, or, at cryogenic temperatures, optical fields. In this thesis, we demonstrate direct mechanical control of NV center spins by coherently driving magnetically-forbidden spin transitions with the resonant lattice strain generated by a mechanical resonator. We then employ mechanical driving to perform continuous dynamical decoupling and extend the inhomogeneous dephasing time of a single NV center spin. Finally, we demonstrate and quantify a spin-strain coupling within the NV center room temperature orbital excited state and propose a dissipative protocol to cool a mechanical resonator mode using this interaction. The methods of mechanical spin control developed here unlock a new degree of freedom within the NV center Hamiltonian that may enable new sensing modes and could provide a route to NV center-mechanical resonator hybrid quantum systems.