Towards optimized surface $\delta$-profiles of nitrogen-vacancy centers activated by helium irradiation in diamond

Abstract

The negatively-charged nitrogen-vacancy (NV) center in diamond has been shown recently as an excellent sensor for external spins. Nevertheless, their optimum engineering in the near-surface region still requires quantitative knowledge in regard to their activation by vacancy capture during thermal annealing. To this aim, we report on the depth profiles of near-surface helium-induced NV centers (and related helium defects) by step-etching with nanometer resolution. This provides insights into the efficiency of vacancy diffusion and recombination paths concurrent to the formation of NV centers. It was found that the range of efficient formation of NV centers is limited only to approximately $10$ to $15$nm (radius) around the initial ion track of irradiating helium atoms. Using this information we demonstrate the fabrication of nanometric-thin ($\delta$) profiles of NV centers for sensing external spins at the diamond surface based on a three-step approach, which comprises (i) nitrogen-doped epitaxial CVD diamond overgrowth, (ii) activation of NV centers by low-energy helium irradiation and thermal annealing, and (iii) controlled layer thinning by low-damage plasma etching. Spin coherence times (Hahn echo) ranging up to $50$ $\mu$s are demonstrated at depths of less than $5$nm in material with $1.1\%$ of ${}^{13}$C (depth estimated by spin relaxation (T${}_1$) measurements). At the end, the limits of the helium irradiation technique at high ion fluences are also experimentally investigated.

arXiv comment27 pages, 10 figures

References in corpus (22)

• The nitrogen-vacancy colour centre in diamond
• High-sensitivity diamond magnetometer with nanoscale resolution
• High nitrogen-vacancy density diamonds for magnetometry applications
• A subpicotesla diamond magnetometer
• Magnetic spin imaging under ambient conditions with sub-cellular resolution
• Chip-scale nanofabrication of single spins and spin arrays in diamond
• Engineering shallow spins in diamond with nitrogen delta-doping
• Probing surface noise with depth-calibrated spins in diamond
• Implantation of labelled single nitrogen vacancy centers in diamond using 15N
• Spin Properties of Very Shallow Nitrogen Vacancy Defects in Diamond
• Extending spin coherence times of diamond qubits by high temperature annealing
• Nanoscale nuclear magnetic resonance with a 1.9-nm-deep nitrogen-vacancy sensor
• Nano-engineered Diamond Waveguide as a Robust Bright Platform for Nanomagnetometry Using Shallow Nitrogen Vacancy Centers
• Creating diamond color centers for quantum optical applications
• Scanning probe microscopy with chemical contrast by nanoscale nuclear magnetic resonance
• Detecting External Electron Spins Using Nitrogen-Vacancy Centers
• Diamond based single molecule magnetic resonance spectroscopy
• Effect of Low-Damage Inductively Coupled Plasma on Shallow NV Centers in Diamond
• Three-dimensional localization of spins in diamond using 12C implantation
• Resolving single molecule structures with nitrogen-vacancy centers in diamond
• Single molecule NMR detection and spectroscopy using single spins in diamond
• An upper limit on the lateral vacancy diffusion length in diamond

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• Tailoring spin defects in diamond
• Single-molecule Scale Magnetic Resonance Spectroscopy using Nitrogen-Vacancy Centers in Diamond
• CVD diamond single crystals with NV centres: a review of material synthesis and technology for quantum sensing applications
• Diamond surface engineering for molecular sensing with nitrogen-vacancy centers
• Protecting a diamond quantum memory by charge state control
• Charge dynamics in near-surface, variable-density ensembles of nitrogen-vacancy centers in diamond
• Nanoscale Sensing Using Point Defects in Single-Crystal Diamond: Recent Progress on Nitrogen Vacancy Center-Based Sensors
• Quantum micro-nano devices fabricated in diamond by femtosecond laser and ion irradiation
• Photoluminescence decomposition analysis: a technique to characterize NV creation in diamond
• Spatially controlled fabrication of single NV centers in IIa HPHT diamond
• Efficient creation of dipolar coupled nitrogen-vacancy spin qubits in diamond
• Comparison of different methods of nitrogen-vacancy layer formation in diamond for widefield quantum microscopy
• Photo-physical properties of He-related color centers in diamond
• Creation and characterization of He-related color centers in diamond
• Impact of helium ion implantation dose and annealing on dense near-surface layers of NV centers