Multi-axis Coherent Control of the Tin Vacancy Center Spin in Diamond*

Group-IV color centers in diamond are a promising building block candidate for future quantum networks. The negatively charged tin-vacancy center (SnV) offers the benefits of strong protection against phonon dephasing and robust cyclicity of its optical transitions arising from its strong spin-orbit interaction. In the work covered in this talk, we deploy an all-optical stimulated Raman drive between the ground and excited states to realize multi-axis coherent control of the SnV spin qubit. We utilize coherent population trapping and optically driven electronic spin resonance to confirm coherent access to the qubit at 1.7 K, and obtain spin Rabi oscillations at a rate of Omega/2pi = 19.0(1) MHz. All-optical Ramsey interferometry reveals a spin dephasing time of T2* = 1.3(3) us and a CPMG-4 dynamical decoupling extends the spin coherence time to T_2 = 0.30(8) ms. These results, paired with previously reported transform-limited photons and integration into photonic nanostructures, establish the SnV as a competitive candidate for quantum network applications.