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 lengthy coherence times even at room temperature, NV centers present one path towards quantum information in the solid state and enable precision metrology with atomic scale spatial resolution. The NV center spin state can be coherently manipulated with resonant magnetic fields, electric fields, or, at cryogenic temperatures, optical fields. Here, we demonstrate direct mechanical control of an NV center spin by coherently driving magnetically-forbidden spin transitions with the resonant lattice strain generated by a bulk-mode mechanical resonator [1,2]. We then employ this mechanical driving to perform continuous dynamical decoupling and extend the inhomogeneous dephasing time of a single NV center spin [3]. Finally, we experimentally demonstrate that a spin-strain coupling exists within the NV center room temperature excited state and theoretically analyze a dissipative protocol that uses this newly discovered coupling to cool a mechanical resonator [4]. 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 diamond-mechanical resonator hybrid quantum systems.
[1] E. R. MacQuarrie, et al, Phys. Rev. Lett. 111, 227602 (2013).
[2] E. R. MacQuarrie, et al, Optica 2, 233 (2015).
[3] E. R. MacQuarrie, et al, Phys. Rev. B 92, 224419 (2015).
[4] E. R. MacQuarrie, et al, arXiv:1605.07131 (2016).