  We demonstrate a photonic circuit with integrated long-lived quantum
memories. Pre-selected quantum nodes - diamond micro-waveguides containing
single, stable, and negatively charged nitrogen vacancy centers - are
deterministically integrated into low-loss silicon nitride waveguides. Each
quantum memory node efficiently couples into the single-mode waveguide (> 1
Mcps collected into the waveguide) and exhibits long spin coherence times of up
to 120 {\mu}s. Our system facilitates the assembly of multiple quantum memories
into a photonic integrated circuit with near unity yield, paving the way
towards scalable quantum information processing.
