Characterizing a 72-channel defect-free array of diamond quantum memories in a photonic integrated circuit

In a previous abstract, we described the unity creation, coupling and integration of diamond "artificial atoms" of silicon vacancy (SiV) and germanium vacancy (GeV) centers with a large-scale photonic integrated circuit (PIC) in aluminum nitride. Here, we present the characterization of our 72-channel quantum memory chip. First, we demonstrate the routing of single-photon emission from 72 distinct optical channels in a fiber-coupled PIC. We performed low-temperature spectroscopy of the emitters, finding near-lifetime-limited optical transitions from both SiV and GeV centers following nanofabrication, micromanipulation, and heterogeneous integration. Additionally, we demonstrate the tuning of optical transitions with the same integrated system, overcoming the spectral inhomogeneities between separate emitter-waveguide systems. These advances set the stage for high-rate, multi-channel photon-mediated entanglement for quantum repeaters and computers.