Nanofabrication of single spins and spin arrays in diamond*

The properties of isolated nitrogen vacancy (NV) centers in diamond make them a promising solid-state qubit candidate for spin-based quantum information processing. However, scaling this system to multi-qubit NV center devices requires methods to accurately place single NV centers in pure diamond substrates. To address this challenge we have developed a method for fabricating single NV centers on 50 nm length scales based on ion implantation and electron beam lithography.\footnote{D. M. Toyli \emph{et al.}, Nano Lett. 10, 3168 (2010).} Secondary ion mass spectroscopy measurements facilitate depth profiling of the implanted nitrogen to provide three-dimensional characterization of the NV center spatial distribution. Finally, electron spin resonance measurements of single NV centers, including temperature-dependent spin coherence measurements, suggest a pathway for optimizing single spin coherence in future devices.