Spin-photon interfaces based on tin-vacancy centers in diamond

Color centers in diamond are quantum systems that can combine long-lived spin degrees of freedom with coherent optical transitions for applications in quantum networks and information processing. The tin-vacancy (SnV) center in diamond in particular combines the characteristic inversion symmetry of the Group IV-vacancy complexes with a large spin-orbit splitting of its ground-state orbitals, enabling the demonstration of long spin coherence times at accessible temperatures. Several challenges remain in the application and understanding of these centers, including a complete theoretical description of the electronic structure, universal spin control, and the engineering of efficient light-matter interaction. Here we discuss theoretical and experimental work towards coherent spin-photon interfaces based on SnV centers at liquid-helium temperatures.