Creating and studying coherent interactions between disparate solid-state quantum systems is a challenge at the intersection of atomic physics, condensed matter physics, and engineering. In general, different physical realizations of a quantum bit (qubit) operate at different frequencies, on different size scales, and couple to different fields. Nonetheless, efforts to create “hybrid quantum systems” are appealing because they could enable a quantum concert – were parts are played by different physical qubits that each offer the best performance in a particular area. There is a growing consensus that mechanical motion is a “plastic” degree of freedom for solid-state qubits, with the potential to form a coherent interface between them, and with light. This has motivated intense research into the coherent interactions between mechanical resonators and qubits formed from photons, trapped atoms, superconducting circuits, quantum dots, and nitrogen-vacancy (NV) centers in diamond, to name a few. I will describe our experiments to coherently couple NV center spins to gigahertz-frequency mechanical resonators using dynamic crystal lattice strain. In high-quality diamond mechanical resonators, we demonstrate coherent Rabi oscillations of NV center spins driven by mechanical motion instead of an oscillating magnetic field [1, 2]. Furthermore, we show that the mechanical resonator is a resource to prolog the NV center’s spin coherence [3]. We also examine how strain can be used to control NV centers through their excited-state, both the room temperature spin-strain coupling [4] and the extremely strong low temperature orbital-strain coupling [5].
[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., Nat. Commun. 8, 14358 (2017).
[5] H. Chen et al., submitted (2018).
