Heterogenous III-V diamond photonic platform for quantum network nodes based on neutral silicon vacancy centers in diamond*

Photonic integration with diamond-based color centers is a promising avenue toward enabling long-haul entanglement distribution, but previously studied color centers lacked the requisite environmental insensitivity for integration in nanofabricated structures [1]. We present a heterogeneously integrated III-V diamond photonic platform specifically designed for neutral silicon vacancy (SiV⁰) color centers. The SiV⁰ center has an array of highly desirable properties, such as long spin coherence and low spectral diffusion, that make it a highly suitable candidate for nodes in quantum networks [2,3]. We utilize a highly selective III-V dry etch and stamp transfer method and entirely avoid etching the diamond substrate, preventing material damage and spectral diffusion associated with diamond nanofabrication. Using 1D photonic crystal cavities and nonlinear frequency conversion in ring resonators, SiV⁰ emission can be Purcell enhanced and efficiently collected, while providing a source of telecommunication photons for long-haul fiber optic transmission.