Generation of Ensembles of Individually Resolvable Nitrogen Vacancies   Using Nanometer-Scale Apertures in Ultrahigh-Aspect Ratio Planar Implantation   Masks
  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. 
Igal Bayn, Edward H. Chen, Matthew E. Trusheim, Luozhou Li, Tim   Schr\"oder, Ophir Gaathon, Ming Lu, Aaron Stein, Mingzhao ...
cond-mat.mtrl-sci quant-ph