Hybrid spin-oscillator systems, formed by single spins coupled to mechanical oscillators, have attracted ever-increasing attention over the last years. These activities were largely triggered by the prospect of employing such devices as high-performance nanoscale sensors or as test-beds for studying macroscopic objects in the quantum regime, provided the spin-oscillator coupling is strong and robust.
In this talk, I will present recent results of such a hybrid spin-oscillator system, where diamond nanomechanical oscillators are coupled to embedded Nitrogen-Vacancy (NV) centers by crystal strain. Our strain coupling is highly robust, potentially strong and promises to yield interesting spin dynamics due to the nontrivial strain coupling Hamiltonian.
I will illustrate these aspects by presenting three of our recent findings on our hybrid quantum device. First, we demonstrate that time-varying strain fields can be employed for strong, coherent driving of the NV center’s spin. Second, we employ such coherent strain driving to effectively decouple the NV center’s spin from environmental noise, and thereby significantly increase the NV’s spin coherence time. These results constitute first essential steps towards future experiments of our hybrid system in the quantum regime.
Due to the unique combination of NV spin structure and strain coupling Hamiltonian, our hybrid spin-oscillator system is one of the few systems that allows studying a so-called closed-contour interaction. Within this approach first results demonstrate that the spin dynamics of this cyclic system strongly depend on the driving fields phases. Our findings therefore present an interesting situation, where the NV center might serve as an atomic interferometer to exactly determine the phase of our mechanical resonator.