Nanophotonic Quantum Memory

A method of making a quantum network node comprising:

• calculating a plurality of scoring function F values for an array of at least two photonic crystal cavity unit cells, each photonic crystal cavity unit cell having a lattice constant α and a hole having a length Hx and a width Hy, wherein the scoring function comprises:
• F
• =
• min
• ⁢
• (
• Q
• ,
• Q
• cutoff
• )
• /
• (
• Q
• cutoff
• ×
• V
• m
• ⁢
• o
• ⁢
• d
• ⁢
• e
• )
• wherein Q is a cavity quality factor, Qcutoff is an estimated maximum realizable Q, and Vmode is a cavity mode volume;
• selecting a value of α, a value of Hz, and a value of Hy for which the scoring function value meets a scoring function value criteria;
• forming, on a substrate, a waveguide region and the array of at least two photonic crystal cavity unit cells based on the selected value α, the selected value Hz, and the selected value Hy;
• implanting at least one ion between a hole of a first photonic crystal cavity unit cell and a second photonic crystal cavity unit cell;
• annealing the at least one implanted ion into at least one quantum defect;
• and
• forming a coplanar microwave waveguide on the substrate in proximity to the array of at least two photonic crystal cavity unit cells.