Single photon emission and single spin coherence of a nitrogen vacancy center encapsulated in silicon nitride

Finding the right material platform for engineering efficient photonic interfaces to solid state emitters has been a long-standing bottleneck for scaling up solid state quantum systems. In this work, we demonstrate that nitrogen rich silicon nitride, with its low auto-fluorescence at visible wavelengths, is a viable quantum photonics platform by showing that nitrogen vacancy centers embedded in nanodiamonds preserve both their quantum optical and spin properties post-encapsulation. Given the variety of high-performance photonic components already demonstrated in silicon nitride, our work opens up a promising avenue for building integrated photonic platforms using solid state emitters.