Temperature sensing with nitrogen vacancy center in diamond
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2022-01-01 |
| Journal | Acta Physica Sinica |
| Authors | Hao-Bin Lin, Shao-Chun Zhang, Dong Yang, Y. H. Zheng, Xiang-Dong Chen |
| Citations | 2 |
| Analysis | Full AI Review Included |
6CCVD Technical Analysis: Diamond NV Center Thermometry
Section titled â6CCVD Technical Analysis: Diamond NV Center ThermometryâExecutive Summary
Section titled âExecutive SummaryâThis analysis reviews the application of Nitrogen-Vacancy (NV) centers in MPCVD diamond for highly sensitive, nanoscale temperature sensing, aligning the research requirements with 6CCVDâs specialized material catalog.
- Core Application: The research focuses on utilizing the quantum spin properties of NV defects in diamond to achieve high-resolution, non-invasive thermometry across broad temperature ranges (5.6 K to 700 K).
- High Spatial Resolution: NV sensors meet the critical demand for temperature measurement at sub-10 ”m scales, demonstrated by applications in mapping local temperature gradients in electronic microstructures and inside living cells (using 50-100 nm nanodiamonds).
- Sensing Mechanism: Temperature is primarily derived from shifts in the NV centerâs Zero-Field Splitting (ZFS, D) value, measured via Optically Detected Magnetic Resonance (ODMR) or, for high speed, monitoring the Zero-Phonon Line (ZPL) shift.
- Achieved Sensitivity: Utilizing spin coherence techniques and high-purity 12C diamond, temperature sensitivities as high as 0.076 mK · Hz-1/2 have been demonstrated through indirect magnetic sensing near the Curie point.
- Material Advantage: Diamondâs high thermal conductivity, chemical inertness, and biological compatibility establish it as the superior material for non-destructive local temperature and thermal property measurement in complex environments.
- 6CCVD Relevance: Replication and advancement of this research require high-purity Single Crystal Diamond (SCD) with precise control over nitrogen concentration and advanced processing (polishing, metalization), all of which are core 6CCVD capabilities.
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted detailing the physical mechanisms and performance metrics of NV thermometry.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Zero-Field Splitting (D) | 2.87 | GHz | Base state spin triplet resonance frequency (ms = 0 to ms = ±1). |
| ZFS Thermal Dependence (dD/dT) | 74.2 ± 0.7 | kHz/K | Rate of D-value change at room temperature (used for linear conversion). |
| Operational Temperature Range | 5.6 - 700 | K | Comprehensive temperature range tested for D/ZPL correlation. |
| ZPL Wavelength | 637 | nm | Wavelength for the zero-phonon line fluorescence readout. |
| Typical Spatial Resolution | < 10 | ”m | NV centers exceed this limit, pushing into the nano-scale. |
| Intracellular Sensor Size | 50 - 100 | nm | Diameter of nanodiamonds used in biological sensing (Fig. 5). |
| Best Sensitivity (ODMR/Direct) | 0.43 | mK · Hz-1/2 | Achieved using spin-locking and ODMR with block diamond. |
| Highest Sensitivity (Indirect) | 0.076 | mK · Hz-1/2 | Achieved using diamond pillar geometry and magnetic phase measurement near Curie point (Ref. 42). |
| Fast Acquisition Time | 10 | ”s | Achieved using three-point sampling method for real-time temperature tracking. |
Key Methodologies
Section titled âKey MethodologiesâThe core temperature sensing methodologies rely on manipulating and reading the NV centerâs spin state, exploiting the temperature-dependent shift of its internal energy levels.
- Material Basis: The experiment requires stable negatively charged NV (NV-) centers embedded in either bulk Single Crystal Diamond (SCD) for stability or Nanodiamonds (NDs) for fine spatial resolution.
- Spin Initialization and Readout (Optical):
- A high-power green laser (typically 532 nm) is applied to excite the NV center to its excited state.
- The center preferentially decays non-radiatively back to the ms = 0 ground state, initializing the spin state.
- Fluorescence is monitored; the ms = ±1 states emit fewer photons than the ms = 0 state, allowing spin state distinction.
- ODMR Measurement (Microwave):
- Microwave (MW) fields near 2.87 GHz are swept across the Zero-Field Splitting (ZFS) frequency.
- When the MW frequency matches the energy difference between ms = 0 and ms = ±1, the spin state flips, causing a detectable drop in fluorescence (the ODMR dip).
- Temperature Extraction: The exact position of the ODMR dip (the D value) is measured. Since D changes linearly with temperature (dD/dT â 74.2 kHz/K at 300 K), this shift is directly converted to local temperature (T).
- Coherent Control for Enhanced Sensitivity:
- Advanced techniques like the Ramsey sequence or dynamic decoupling (e.g., three Ï pulses) are used to eliminate magnetic field interference (Zeeman shifts) and measure the temperature-induced phase accumulation (ÎΊ) proportional only to ÎD, maximizing T2 coherence time and sensitivity.
- Alternative All-Optical Method (ZPL): For fast, less demanding measurements, the direct shift of the Zero-Phonon Line (ZPL) at 637 nm can be monitored optically, bypassing the need for complex microwave manipulation.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & Capabilitiesâ6CCVD is uniquely positioned to supply the advanced diamond materials and engineering services required to replicate and extend the state-of-the-art temperature sensing research detailed in this paper.
| Paper Requirement / Research Need | 6CCVD Custom Solution | Engineering Relevance |
|---|---|---|
| Ultra-High Purity Diamond (for long T2 coherence time, Refs. 28, 29) | Optical Grade Single Crystal Diamond (SCD): Characterized by native nitrogen content in the ppb range, enabling maximal quantum coherence and sensitivity. | Essential for achieving the best reported sensitivities (e.g., 0.43 mK · Hz-1/2) by minimizing environmental decoherence. |
| Controlled NV Concentration (bulk vs. single NV) | Custom N-Doping Profiles: Precise nitrogen introduction during MPCVD growth or controlled post-growth implantation and annealing services (N or N+V formation). | Allows researchers to tune the NV density for either ensemble (high signal) or single-NV (high spatial resolution) sensing applications. |
| Integration & Device Fabrication (e.g., antennas, heating lines, Refs. 9, 12) | In-House Metalization Services: Custom deposition of Ti/Pt/Au, Au, Pt, Pd, W, or Cu contacts directly onto the diamond wafer. | Critical for patterning integrated microwave waveguides, heating elements (Fig. 12), and electrical contacts necessary for device-level thermometry. |
| Large-Scale Sensor Arrays & Micro-Chips (Fig. 11) | Large Area Diamond Platforms: Polycrystalline Diamond (PCD) wafers up to 125 mm diameter, or Single Crystal Diamond (SCD) plates up to 10 mm substrates. | Supports the fabrication of complex, high-density sensor arrays for industrial heat mapping or semiconductor characterization (Ref. 54). |
| Scanning Probe Microscopy Tips (Fig. 12) | Ultra-Low Surface Roughness Polishing: SCD polishing services achieve Ra < 1 nm, and Inch-size PCD polishing is optimized for Ra < 5 nm. | Minimizes optical scattering and ensures reliable contact necessary for thermal conductivity measurements using AFM tips functionalized with NDs. |
| Flexibility in Sensor Dimensions (nanodiamonds to bulk plates) | Custom Dimensions and Thicknesses: SCD/PCD available from 0.1 ”m films up to 500 ”m wafers, with substrates up to 10 mm. | Supports both bulk experiments (high stability) and miniaturized sensor elements tailored for integration. |
Applicable Materials:
- Optical Grade SCD: Ideal for all high-sensitivity quantum sensing applications requiring long T2 coherence times and maximum thermal stability.
- Custom N-Doped SCD: Necessary for research requiring specific, repeatable NV concentration profiles for ensemble or single-shot measurements.
- Metalized PCD/SCD: Perfect platform for developing chip-scale electronic device thermometry (Figs. 9, 11).
Engineering Support:
6CCVDâs in-house PhD engineering team specializes in MPCVD growth and material post-processing, offering consultation and technical support for material selection, doping optimization, and device integration requirements in Quantum Sensing and Thermal Metrology projects.
Call to Action:
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Temperature is the most intuitive and widespread in various physical quantities. Violent changes in temperature usually implies the appearing of fluctuations in physical properties of an object. Therefore, temperature is often an important indicator. With the development of science and technology, the scales in many fields are being more and more miniaturized. However, there are no mature temperature measurement systems in the case where the spatial scale is less than 10 ÎŒm. In addition to the requirement for spatial resolution, the sensor ought to exert no dramatic influence on the object to be measured. The nitrogen vacancy (NV) center in diamond is a stable luminescence defect. The measurements of its spectrum and spin state can be used to obtain the information about physical quantities near the color center, such as temperature and electro-magnetic field. Owing to its stable chemical properties and high thermal conductivity, the NV center can be applied to the noninvasive detection for nano-scale researches. It can also be used in the life field because it is non-toxic to cells. Moreover, combined with different techniques, such as optical fiber, scanning thermal microscopy, NV center can be used to measure the local temperatures in different scenarios. This review focuses on the temperature properties, the method of measuring temperature, and relevant applications of NV centers.