  A central challenge in developing magnetically coupled quantum registers in
diamond is the fabrication of nitrogen vacancy (NV) centers with localization
below ~20 nm to enable fast dipolar interaction compared to the NV decoherence
rate. Here, we demonstrate the targeted, high throughput formation of NV
centers using masks with a thickness of 270 nm and feature sizes down to ~1 nm.
Super-resolution imaging resolves NVs with a full-width maximum distribution of
$26\pm7$ nm and a distribution of NV-NV separations of $16\pm5$ nm.

Materials Science;Quantum Physics