Spin and Orbital Resonance Driven by a Mechanical Resonator*

I describe our experiments to drive spin and orbital resonance of single diamond nitrogen-vacancy (NV) centers using the gigahertz-frequency strain oscillations produced within a diamond acoustic resonator. Strain-based coupling between a resonator and a defect center takes advantage of intrinsic and reproducible coupling mechanisms while maintaining compatibility with conventional magnetic and optical techniques, thus providing new functionality for quantum-enhanced sensing and quantum information processing. Using a spin-strain interaction at room temperature, we demonstrate coherent spin control [1] and spin coherence protection [2]. At cryogenic temperatures, we use orbital-strain interactions driven by a diamond acoustic resonator to examine multi-phonon orbital resonance of a single NV center [3]. We drive a strong mechanical modulation of the orbital state energies in the side-band resolved limit and produce nine orders of coherent Raman sidebands. When we match the resonator frequency to half of the orbital splitting, we demonstrate resonance between the orbital states using a transverse orbital-strain interaction. The resulting dressed orbital states display Autler-Townes splitting as a function of resonator amplitude that is well-described by a 2-phonon resonance process. Finally, we discuss orbital decoherence protection as means of engineering NV centers to be a better spin-photon interface as a potential application of these techniques.
1. E. R. MacQuarrie et al., Optica 2, 233 (2015).
2. E. R. MacQuarrie et al., Phys. Rev. B 92, 224419 (2015).
3. H. Chen et al., Phys. Rev. Lett. 120, 167401 (2018).