Spin coherence and depths of single nitrogen-vacancy centers created by ion implantation into diamond via screening masks

Abstract

We characterize single nitrogen-vacancy (NV) centers created by 10-keV N + ion implantation into diamond via thin SiO 2 layers working as screening masks. Despite the relatively high acceleration energy compared with standard ones (< 5 keV) used to create near-surface NV centers, the screening masks modify the distribution of N + ions to be peaked at the diamond surface [Ito et al., Appl. Phys. Lett. 110, 213105 (2017)]. We examine the relation between coherence times of the NV electronic spins and their depths, demonstrating that a large portion of NV centers are located within 10 nm from the surface, consistent with Monte Carlo simulations. The effect of the surface on the NV spin coherence time is evaluated through noise spectroscopy, surface topography, and X-ray photoelectron spectroscopy.

Protecting qubit coherence by spectrally engineered driving of the spin environment

“…An alternative and complementary approach aims at manipulating the noise frequency spectrum of the bath itself, a technique referred to as spin-bath driving [13] and originally developed in nuclear magnetic resonance and known as spin decoupling [14]. Recent work has shown that monochromatic driving of a spin bath can extend the coherence of bulk [15] and near-surface NV centers [16,17]. An intrinsic limitation of this monochromatic approach is that it does not efficiently address spectrally broad classes of spins that naturally emerge in inhomogeneous environments and interacting spin baths [18].…”