TR12 centers in diamond as a room temperature atomic scale vector magnetometer
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2022-06-02 |
| Journal | npj Quantum Information |
| Authors | Jonas Foglszinger, Andrej Denisenko, Thomas Kornher, M. Schreck, Wolfgang Knolle |
| Institutions | Centre National de la Recherche Scientifique, Lumiphase (Switzerland) |
| Citations | 13 |
| Analysis | Full AI Review Included |
TR12 Centers in Diamond: Enabling High-Field Vector Magnetometry
Section titled “TR12 Centers in Diamond: Enabling High-Field Vector Magnetometry”Executive Summary
Section titled “Executive Summary”This technical analysis focuses on the research demonstrating TR12 defects in MPCVD diamond as a robust, room-temperature alternative to NV centers for quantum sensing, specifically high-field vector magnetometry.
- High-Field Vector Magnetometry: TR12 centers exhibit strong Optically Detected Magnetic Resonance (ODMR) contrast, maintained even in strong off-axis magnetic fields (up to 1 T and beyond).
- Superior Angular Acceptance: Unlike NV centers, which are limited to sensing fields aligned with their symmetry axis, TR12 centers allow for full vector magnetometry across arbitrary field orientations under ambient conditions.
- Coherent Control: Coherent control of the excited triplet spin state (S=1) was successfully demonstrated at room temperature on a single defect level, confirming suitability for quantum information processing (QIP).
- Material Foundation: The defects were created in Chemical Vapor Deposition (CVD) diamond via 12C ion implantation or 10 MeV electron irradiation, followed by 800 °C annealing.
- Key Performance Metric: Estimated shot-noise limited magnetic sensitivity for a single TR12 center is 3.9 µT Hz-1/2.
- Electronic Structure: The spin system is characterized by a metastable triplet state (S=1) with zero-field splitting parameters D = 1636.6 MHz and E = 896.6 MHz.
Technical Specifications
Section titled “Technical Specifications”| Parameter | Value | Unit | Context |
|---|---|---|---|
| Zero-Field Splitting (D) | 1636.6 | MHz | Triplet state (S=1) Hamiltonian |
| Zero-Field Splitting (E) | 896.6 | MHz | Triplet state (S=1) Hamiltonian |
| Emitting State Lifetime (τ) | 4.7 | ns | Singlet state (G-S transition) |
| Metastable Triplet Lifetime (τmeta) | 6.79 | µs | Overall decay of metastable population |
| Short-Lived Triplet State Lifetime (τz) | 375 | ns | Determined via Rabi oscillation fit |
| ODMR Contrast (Bulk, 100 mT) | Up to 25 | % | Wide angular range (TR12) |
| ODMR Contrast (Single, 147 mT) | 10.8 | % | Off-axis orientation (superior to NV) |
| Maximum Field Acceptance | > 1 | T | Demonstrated capability for sensing |
| Magnetic Sensitivity (η) | 3.9 | µT Hz-1/2 | Shot-noise limited estimate for single center |
| TR12 Creation Annealing Temp | 800 | °C | Post-implantation/irradiation processing |
Key Methodologies
Section titled “Key Methodologies”The TR12 centers were created and characterized using high-purity CVD diamond substrates and advanced quantum optics techniques:
- Substrate Material: High-quality Chemical Vapor Deposition (CVD) diamond, typically oriented along the (100) plane.
- Defect Creation (Option 1): 12C ion implantation at energies of 10 keV or 370 keV, utilizing a dose of 1011 ions per cm-2.
- Defect Creation (Option 2): 10 MeV electron irradiation, utilizing a high dose of 5 x 1016 e per cm-2.
- Thermal Processing: Post-implantation/irradiation annealing performed at 800 °C for 1 hour to activate and stabilize the TR12 centers.
- Optical Setup: Home-built confocal microscope utilizing 410 nm linear polarized laser excitation for fluorescence and ODMR measurements at room temperature.
- Microwave Delivery: Microwave radiation was supplied to the sample via a lithographically defined golden microwave waveguide deposited directly on the diamond surface.
- Magnetic Field Control: A permanent NdFeB magnet (1.4 T magnetization) was used, controlled by high-precision stepper motors to apply magnetic fields of variable magnitude and direction.
6CCVD Solutions & Capabilities
Section titled “6CCVD Solutions & Capabilities”6CCVD is uniquely positioned to supply the high-quality MPCVD diamond materials and integrated processing required to replicate and advance this research into scalable, high-field vector magnetometry devices.
Applicable Materials for TR12 Research
Section titled “Applicable Materials for TR12 Research”To achieve the low intrinsic defect density and high optical quality necessary for quantum sensing applications, 6CCVD recommends the following materials:
- Optical Grade Single Crystal Diamond (SCD): Provides the highest purity and lowest nitrogen concentration, minimizing background noise and maximizing the coherence time of the introduced TR12 defects.
- High-Purity Polycrystalline Diamond (PCD): For applications requiring large area coverage (e.g., bulk magnetometry arrays), 6CCVD offers high-purity PCD wafers up to 125 mm in diameter, suitable for uniform defect creation and ensemble measurements.
- Substrate Optimization: 6CCVD supplies substrates optimized for subsequent high-temperature annealing (800 °C used in this study) required for defect activation.
Customization Potential
Section titled “Customization Potential”The research utilized specific dimensions, surface preparation, and integrated microwave structures, all of which fall within 6CCVD’s core capabilities:
| Research Requirement | 6CCVD Customization Service | Technical Specification |
|---|---|---|
| Substrate Dimensions | Custom plates and wafers for single-defect or bulk studies. | SCD plates up to 10 mm thick; PCD wafers up to 125 mm diameter. |
| Surface Finish | Ultra-smooth surfaces required for high-resolution optical access and lithography. | Precision Polishing: Ra < 1 nm (SCD) and Ra < 5 nm (Inch-size PCD). |
| Integrated Microwave Structures | Lithographically defined golden waveguide used for microwave delivery. | Custom Metalization: In-house deposition of Au, Pt, Ti, Pd, Cu, or W for integrated microwave circuits and electrical contacts. |
| Thickness Control | Precise control over the CVD layer thickness for optimized implantation depth. | SCD/PCD thickness control from 0.1 µm to 500 µm. |
Engineering Support
Section titled “Engineering Support”The successful implementation of TR12 centers for vector magnetometry requires precise control over material purity, defect creation, and post-processing.
- Material Selection: 6CCVD’s in-house PhD team can assist researchers in selecting the optimal SCD or PCD grade based on required nitrogen concentration and desired defect density for similar High-Field Vector Magnetometry or Quantum Information Processing (QIP) projects.
- Process Optimization: We offer consultation on optimizing substrate preparation prior to ion implantation or electron irradiation to ensure maximum defect yield and stability post-800 °C annealing.
- Global Logistics: 6CCVD ensures reliable global shipping (DDU default, DDP available) for sensitive quantum materials.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.