Heterogenous Integration of Diamond and Lithium Niobate Nanophotonics for Quantum Networks*

Group-IV diamond color centers are promising qubit candidates for quantum nodes due to their optical addressability, excellent spin properties, and compatibility with nanophotonic integration. However, a monolithic diamond platform lacks the capabilities necessary for scalable quantum networks due to diamond’s structural symmetry and absence of second order nonlinearity. To address this challenge, heterogenous integration of diamond quantum systems with lithium niobate is an attractive approach. We report coupling of tapered diamond nanobeams and lithium niobate passive components with high adiabatic transmission efficiencies. We then present the ability to address and characterize single color centers in an integrated device. Lastly, we discuss the potential for spin control and quantum interference in the platform of interest.