Mechanical spin control of nitrogen-vacancy centers in diamond

Abstract: As spin-based quantum technology evolves, the ability to manipulate spin with non-magnetic fields is critical - both for the development of hybrid quantum systems and for compatibility with conventional technology. Particularly useful examples are electric fields, optical fields, and mechanical lattice vibrations. The last of these represents direct spin-phonon coupling, which has garnered fundamental interest as a potential mediator of spin-spin interactions, but could also find applications in high-stability inertial sensing. In this Letter, we demonstrate direct coupling between phonons and nitrogen-vacancy (NV) center spins in diamond by inducing spin transitions with mechanically-driven harmonic strain. The ability to control NV spins mechanically can enhance NV-based quantum metrology, grant access to all transitions within the spin-1 quantum state of the NV center, and provide a platform to study spin-phonon interactions at the level of a few interacting spins.