Shallow nitrogen-vacancy (NV) centers are quantum defects engineered to sit close to the diamond surface — typically within 10–50 nm or 1–10 μm of the top layer. That proximity is exactly what makes them valuable. By placing a stable quantum sensor nanometers from a sample, researchers can detect magnetic fields, electrical currents, temperature, and stress with spatial resolution that conventional measurement approaches struggle to reach. For research institutions and industrial teams pursuing nanoscale sensing, understanding how shallow NV diamond is fabricated has become a practical prerequisite. ViQium Technologies Co., Ltd., a Shanghai-headquartered developer of quantum diamond and emerging two-dimensional phosphorus-based materials, has built an integrated fabrication chain covering diamond crystal growth, ion irradiation, and high-temperature annealing, positioning it as a supplier of both shallow NV diamond materials and the supporting measurement know-how.
What Defines a Shallow NV Center
NV center — a quantum defect system embedded within the diamond lattice in which a nitrogen atom substitutes for a carbon atom adjacent to a vacant lattice site. It functions as an extremely small quantum sensor inside a diamond crystal.
Shallow NV diamond — diamond material in which NV centers are deliberately created at controlled depths near the surface, enabling surface-sensitive and near-field measurement rather than bulk sensing.
Why Depth and Crystallographic Alignment Matter
Depth determines what a shallow NV center can sense. A center placed too deep loses sensitivity to surface phenomena; one placed too close risks degraded coherence from surface noise. Equally important is crystallographic orientation, which governs how the defect responds to applied magnetic fields and how efficiently it can be addressed optically and via microwaves. This is why nanometer-scale control of NV center depth and crystallographic alignment is described as a core capability for atomic-scale precision — a requirement driven by applications such as atomic force microscopy probes and surface sensing.
The Operating Principle in Brief
Every shallow NV center operates through three fundamental steps. First, optical initialization: a green laser excites the defect, preparing its quantum state into a well-defined starting condition. Second, quantum manipulation: a precisely tuned microwave field controls the spin state by adjusting frequency, duration, and related parameters. Third, optical readout: laser excitation produces red fluorescence whose intensity varies with the final quantum state, allowing surrounding physical changes to be measured. Because NV centers operate at room temperature and resolve features at the nanoscale, they offer a practical pathway compared with approaches requiring cryogenic temperatures or complex vacuum systems.
Core Fabrication Techniques for Shallow NV Diamond
ViQium has established a comprehensive technology platform for fabricating NV centers in diamond through high-pressure high-temperature (HPHT) and chemical vapor deposition (CVD) methods. The platform supports controllable fabrication of quantum diamond materials ranging from single NV centers, with coherence times exceeding 200 μs, to ppm-level high-concentration NV center ensembles.
Substrate Growth and Purity Control
Fabrication begins with the crystal. High purity diamond serves as the starting substrate, characterized by nitrogen content below 5 ppb, boron content below 1 ppb, and carbon-12 enrichment of 98.9%, available in <100>, <110>, and <111> orientations. Low background impurities matter because unintended nitrogen introduces uncontrolled defects that broaden the measured signal and reduce repeatability.
Nitrogen Introduction and Ion Irradiation
Controlled nitrogen incorporation, combined with ion irradiation, allows NV centers to be created at targeted depths and densities rather than left to chance. The company's proprietary advanced color center engineering supports precise control over NV, SiV, and other color center types in engineered quantum diamond materials.
High-Temperature Annealing
Annealing repairs lattice damage introduced during irradiation and activates the nitrogen-vacancy complexes, converting them into optically addressable defects. Together, growth, irradiation, and annealing form the complete process chain ViQium has established independently.
Damage-Free Formation and Stress Mitigation
ViQium holds patented technologies for the damage-free fabrication of nitrogen-vacancy centers in diamond and applies proprietary techniques for NV center stress mitigation. These capabilities support advanced composite processing of superhard materials and enable diamond materials to transition toward high-precision sensing and quantum information applications.
Specifications of Shallow NV Diamond Products
Shallow NV diamond is supplied with a transverse relaxation time (T₂*) of 100–300 ns, an NV density of 1–2 ppm, and NV depths of either 10–50 nm or 1–10 μm. Crystal orientations include <100> and <111>, with standard dimensions of 2×2×0.5 mm and 3×3×0.5 mm. Product customization and factory calibration and characterization data are offered with each order. The broader quantum diamond portfolio spans single NV diamond, ensemble NV diamond, ultra-high-density NV diamond at 10–45 ppm, high purity diamond, micro- and nano-scale NV diamond, NV diamond anvils, SiV diamond, and black phosphorus materials.
Quality Assurance and Data Traceability
ViQium implements batch-level control and traceability throughout the production and delivery of NV center quantum diamond, ensuring performance stability and consistency across material batches. A fully integrated quality and traceability system spans design, production, and testing. For technical information and project data generated during customer applications, the company applies internal access control and information segregation mechanisms to protect the security and independence of technical and application-related data.
Applications Enabled by Shallow NV Diamond
Shallow NV diamond is widely applied in wide-field current imaging, wide-field magnetic imaging, and ultrafast nonlinear photonic sensing. Related quantum diamond materials support super-resolution bioimaging and cell tracking, intracellular quantum sensing, miniaturized magnetometers and thermometers, and information security and anti-counterfeiting, as well as quantum computing, networking, simulation, and single-molecule nuclear magnetic resonance.
Support Beyond the Material
Beyond material supply, ViQium provides an NV Diamond Selection Guide and professional online consultation, categorizing products by application requirement — magnetic field sensing, magnetic imaging, or temperature sensing — so customers need not purchase multiple samples for comparison. For teams without prior NV center experimental experience, the company offers an integrated solution combining diamond samples, optical components, and system configuration support, with expertise spanning optical alignment, signal acquisition, and magnetic field calibration. Standard products are delivered within 28 days, while conventional customized products are delivered within 45 days, with flexible customization available starting from a single piece.
By combining surface-precise material engineering with end-to-end measurement support, ViQium gives research groups and industrial developers a single, traceable path from material selection to working shallow NV sensing systems.
https://en.viqiumtech.com/
ViQium Technologies Co., Ltd.
