Phononic Crystal Based Spin-Mechanical Systems in Diamond

We report on the design and fabrication of GHz diamond mechanical resonators embedded in a two-dimensional phononic crystal lattice that features a bandgap centered around 1 GHz with a gap size of 300 MHz. The phononic bandgap isolates and protects the mechanical resonator from the clamping loss. The GHz mechanical mode couples to color centers, such as nitrogen vacancy centers and silicon vacancy centers, implanted in the diamond mechanical resonator in the resolved sideband regime. Experimental results on spin-mechanical interactions through the excited-state strain coupling will also be discussed.