Tunable Density, Depth-Confined Nitrogen-Vacancy Centers in Diamond Achieve Twofold Improvement in Control
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Creating nitrogen-vacancy (NV) centres in diamond represents a significant step forward in nanoscale technology, and researchers are now achieving unprecedented control over their creation and properties. Lillian B. Hughes Wyatt, Shreyas Parthasarathy, Isaac Kantor, and colleagues at the University of California, Santa Barbara, have developed a method for engineering these defects with remarkable precision. Their technique, involving carefully controlled nitrogen doping during diamond growth, allows for tunable control over both the depth and density of NV centres, achieving a twofold improvement in depth confinement compared to existing methods. This advancement promises to enhance the sensitivity of nanoscale sensors and unlock new possibilities in fields ranging from nanoscale nuclear magnetic resonance to entanglement-enhanced metrology, as demonstrated by the team’s successful imaging of magnetism in the two-dimensional material CrSBr. Engineering shallow nitrogen-vacancy (NV) centers in diamond unlocks new possibilities for nanoscale quantum sensing.
This research demonstrates that creating near-surface NVs through nitrogen doping during diamond growth allows for precise control over both NV depth and density, surpassing the limitations of traditional ion implantation. This ultimately results in highly-sensitive single defects and ensembles with coherence limited by interactions between neighboring NVs. NV Center Sensing of CrSBr Magnetism Scientists are leveraging nitrogen-vacancy (NV) centers in diamond as nanoscale sensors to detect magnetic fields.
This research focuses on using these shallow NV centers to investigate the magnetic properties of chromium sulfide bromide (CrSBr), a two-dimensional material with promising magnetic characteristics. The goal is to achieve highly sensitive and spatially resolved magnetic field detection. Diamond samples were grown using a chemical vapor deposition process, with careful control over substrate orientation to optimize NV center properties. The diamond was then encapsulated with a protective layer of silicon dioxide. CrSBr was carefully transferred onto the diamond surface using a technique that preserves its layered structure. Researchers characterized the NV centers to determine their depth and control their charge state, which significantly impacts their sensing capabilities. An optical microscope and specialized magnetic resonance techniques were used to detect the magnetic field produced by the CrSBr. Data analysis involved processing the magnetic resonance signals and comparing them with simulations of the magnetic field. These simulations, performed using advanced software, accounted for the limitations of the optical microscope and the diffraction of light.
The team also developed methods to address ambiguous signals, improving the accuracy of their measurements. The research successfully demonstrated the ability of shallow NV centers to detect the magnetic field from CrSBr. The experimental results agreed well with the simulations, validating the approach. Precise control over NV center depth is crucial for achieving high sensitivity and spatial resolution. Maintaining the charge state of the NV centers is also essential for reliable measurements. This NV-CrSBr system holds promise for high-resolution magnetic imaging of two-dimensional materials.
Precise Depth Control of NV Centers in Diamond Scientists have made a major advance in the controlled creation of nitrogen-vacancy (NV) centers in diamond, enabling new capabilities for nanoscale quantum sensing. The study demonstrates that nitrogen doping during diamond growth allows precise control over both the depth and density of NV centers, overcoming the variability inherent in conventional ion-implantation techniques. Experiments show a mean NV depth of 5.8 ± 1.6 nm in doped samples, compared with 8.7 ± 3.5 nm for ion-implanted diamonds, representing more than a twofold improvement in depth confinement. This enhanced control significantly reduces variability in NV properties and increases the yield of usable quantum sensors. Measurements of individual NV centers reveal that doping produces highly coherent defects even at very shallow depths. Depth-dependent studies show coherence times comparable to the best ion-implanted samples, despite the increased influence of surface-related decoherence. The researchers further demonstrate that sensitivity to AC magnetic fields and electric dipole moments can be tuned by adjusting NV depth. Notably, the shallowest NV center, located just 3 nm below the surface, is capable of detecting a single electron spin on the diamond surface within approximately 100 microseconds. To illustrate the practical impact of these advances, the team used shallow NV centers to image magnetic order in few-layer CrSBr, a two-dimensional magnetic material. By tuning the NV density, they created ensembles whose coherence was limited primarily by NV–NV interactions, enabling highly sensitive magnetic imaging. Together, these results highlight the potential of doped shallow NV centers to advance nanoscale quantum sensing applications, including nanoscale NMR, magnetic imaging, and entanglement-enhanced metrology. The ability to fabricate precisely positioned, highly sensitive NV centers marks an important step toward fully realizing the capabilities of diamond-based quantum sensors. Shallow NV Centers Image 2D Magnetism This research demonstrates a significant advance in the engineering of nitrogen-vacancy (NV) centers in diamond, nanoscale defects with potential for highly sensitive sensing applications. Scientists successfully created shallow NV centers through nitrogen doping during diamond growth, achieving improved control over both the depth and density of these defects compared to previous methods. This precise control results in highly coherent NV centers, limited primarily by interactions between neighboring defects, paving the way for enhanced sensor performance.
The team further validated their approach by utilizing these shallow NV centers to image magnetism in a two-dimensional material, chromium sulfide bromide. Researchers acknowledge that the positioning of NV centers is still limited by the diamond growth process, and further refinement is needed to achieve even greater precision. Future work may combine this doping technique with methods for laterally confining NV centers, potentially leading to even higher sensitivity scanning probes and precise positioning of sensors for targeted measurements. This work establishes a robust method for creating highly coherent, near-surface NV sensors with approximately 1. 6 nanometer depth confinement, representing a key step towards realizing the full potential of NV centers in diverse sensing applications. 👉 More information 🗞 Creation of Depth-Confined, Shallow Nitrogen-Vacancy Centers in Diamond With Tunable Density 🧠 ArXiv: https://arxiv.org/abs/2512.11242 Tags: