Simultaneous imaging of magnetic field and temperature using a wide-field quantum diamond microscope
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2021-03-25 |
| Journal | EPJ Quantum Technology |
| Authors | Yulei Chen, Zhonghao Li, Hao Guo, Wu Da-Jin, Jun Tang |
| Institutions | Shanxi Normal University, North University of China |
| Citations | 8 |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Wide-Field Quantum Diamond Microscopy
Section titled âTechnical Documentation & Analysis: Wide-Field Quantum Diamond MicroscopyâThis document analyzes the requirements and achievements detailed in the research paper âSimultaneous imaging of magnetic field and temperature using a wide-field quantum diamond microscopeâ and outlines how 6CCVDâs advanced MPCVD diamond solutions can support and enhance this critical quantum sensing technology.
Executive Summary
Section titled âExecutive SummaryâThe research successfully demonstrates a wide-field quantum diamond microscope capable of simultaneous, real-time imaging of magnetic fields and temperature, a crucial capability for chip failure detection and PCB quality control.
- Core Value Proposition: Simultaneous, wide-field imaging of magnetic fields and temperature using Nitrogen-Vacancy (NV) centers in CVD diamond.
- Key Achievement: Demonstrated high sensitivity for both parameters: Magnetic field sensitivity of 1.8 ”T/Hz1/2 and temperature sensitivity of 0.4 K/Hz1/2.
- Material Requirement: The system relies on a high-quality, 50 ”m thick, (100) oriented CVD diamond plate with an estimated NV concentration of ~1 ppm.
- Spatial Resolution: Achieved a spatial resolution of 1.3 ”m, limited by optical diffraction.
- Application Focus: Successfully applied the technique to monitor integrated cell heaters and detect faulty solder joints on a Printed Circuit Board (PCB).
- 6CCVD Solution: 6CCVD specializes in providing the necessary high-purity Single Crystal Diamond (SCD) substrates with precise thickness control (0.1 ”m to 500 ”m) and superior surface polishing (Ra < 1 nm) essential for maximizing photon collection efficiency and spatial resolution in wide-field ODMR systems.
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the experimental results and methodology described in the paper.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Magnetic Field Sensitivity (η) | 1.8 | ”T/Hz1/2 | Optimal photon shot noise-limited sensitivity |
| Temperature Sensitivity | 0.4 | K/Hz1/2 | Fundamentally limited sensitivity |
| Spatial Resolution | 1.3 | ”m | Restricted by optical diffraction limit |
| Field of View (FOV) | 400 x 300 | ”m2 | Imaging area (800 x 600 pixels) |
| Diamond Thickness | 50 | ”m | Polished CVD diamond chip used |
| Crystal Orientation | (100) | N/A | Normal vector parallel to [100] direction |
| NV Center Concentration | ~1 | ppm | Estimated concentration in the CVD chip |
| Excitation Wavelength | 532 | nm | Laser illumination source |
| Laser Power Density | 10 | W/mm2 | Used for the imaging system |
| Microwave Frequency Range | 2.5 to 3.2 | GHz | Swept range for ODMR measurement |
| ODMR Linewidth (ÎV) | 12 | MHz | Used in sensitivity calculation |
| ODMR Contrast (C) | 2.8 | % | Used in sensitivity calculation |
Key Methodologies
Section titled âKey MethodologiesâThe wide-field quantum diamond microscope relies on precise optical and microwave control coupled with high-quality diamond material.
- Illumination and Excitation: The diamond is illuminated with a 532 nm laser beam at a power density of 10 W/mm2 through a self-assembled confocal wide-field imaging system.
- Fluorescence Collection: Resulting NV fluorescence (650-800 nm) is collected via an objective lens and imaged onto a scientific complementary metal oxide semiconductor (sCMOS) camera.
- Microwave (MW) Resonance: A resonance MW field (20 dBm power) is fed to the diamond via a microwave antenna, sweeping the frequency from 2.5 to 3.2 GHz in 4000 steps.
- Bias Magnetic Field: An external magnetic field (B0 = 7.5 mT) is applied to provide a known magnetic bias and resolve the eight spin resonance lines.
- Imaging and Synchronization: The sCMOS camera (pixel size ~5 ”m) is synchronized to the MW source sweep, acquiring a stack of images where each image represents a specific microwave frequency.
- Decoupling: By simultaneously measuring the frequency shifts of the resonance frequencies of all four possible NV axes, the effects of temperature (ÎŽT) and magnetic field (BNV) are decoupled, allowing for simultaneous imaging.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & Capabilitiesâ6CCVD is uniquely positioned to supply the advanced diamond materials required to replicate, optimize, and scale the wide-field quantum diamond microscopy platform described in this research.
Applicable Materials
Section titled âApplicable MaterialsâTo achieve the high sensitivity and spatial resolution demonstrated, the researchers require high-quality, low-strain SCD.
| 6CCVD Material Recommendation | Specification Match | Optimization Potential |
|---|---|---|
| Optical Grade Single Crystal Diamond (SCD) | (100) Orientation, 50 ”m thickness, Low strain. | Essential for minimizing background noise and maximizing coherence time (T2). |
| Custom Thickness SCD Wafers | Required 50 ”m thickness. | 6CCVD offers SCD from 0.1 ”m up to 500 ”m. Thinner membranes (e.g., < 10 ”m) can be provided for enhanced proximity sensing applications. |
| Controlled NV Density SCD | Required ~1 ppm NV concentration. | We supply high-purity SCD (low native NV) suitable for precise NV creation via ion implantation, or as-grown SCD with controlled nitrogen incorporation for specific volume sensing needs. |
| Heavy Boron Doped Diamond (BDD) | N/A (Not used in this paper). | Future Extension: BDD substrates can be used as highly conductive platforms for integrated microwave transmission lines, potentially replacing external antennas and improving MW delivery uniformity across the wide field of view. |
Customization Potential
Section titled âCustomization PotentialâThe success of this wide-field imaging technique depends heavily on the quality and customization of the diamond substrate.
- Precision Polishing: The paper relies on high photon collection efficiency. 6CCVD guarantees Ra < 1 nm polishing for SCD, minimizing surface scattering losses and maximizing the signal-to-noise ratio (SNR) crucial for achieving the reported sensitivities (1.8 ”T/Hz1/2).
- Custom Dimensions: While the FOV was 400 x 300 ”m2, 6CCVD can supply SCD plates up to 10 x 10 mm and Polycrystalline Diamond (PCD) wafers up to 125 mm in diameter, enabling significantly larger wide-field imaging systems.
- Integrated Metalization: For advanced setups requiring integrated microwave antennas or heating elements directly on the diamond surface, 6CCVD offers in-house metalization services, including Ti/Pt/Au, W, Cu, and Pd layers, ensuring robust, high-frequency performance.
- Substrate Engineering: We provide custom substrates up to 10 mm thick, allowing researchers to mount thin sensing layers (like the 50 ”m layer used here) onto robust carriers for easier handling and integration into complex optical setups.
Engineering Support
Section titled âEngineering Supportâ6CCVDâs in-house PhD team specializes in the material science of quantum defects and can assist researchers in optimizing diamond selection for specific applications.
- Material Selection for Quantum Sensing: We provide consultation on the optimal crystal orientation ((100) vs. (111)), nitrogen concentration, and surface termination necessary to maximize spin coherence times (T2) and ODMR contrast for similar Chip Failure Detection and Real-Time Device Monitoring projects.
- Surface Preparation: Our expertise ensures the diamond surface is prepared to minimize strain and maximize NV center formation yield post-implantation, which is critical for achieving high spatial uniformity in wide-field imaging.
- Global Logistics: We offer reliable Global Shipping (DDU default, DDP available), ensuring sensitive quantum materials arrive safely and promptly worldwide.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Abstract Quantum sensing based on nitrogen-vacancy centers in diamond has shown excellent properties. Combined with the imaging technique, it shows exciting practicability. Here, we demonstrate the simultaneously imaging technique of magnetic field and temperature using a wide-field quantum diamond microscope. We describe the operating principles of the diamond microscope and report its sensitivity (magnetic field ${\sim}1.8~\mu \mbox{T/Hz}^{1/2}$ <mml:math xmlns:mml=âhttp://www.w3.org/1998/Math/MathMLâ> <mml:mo>âŒ</mml:mo> <mml:mn>1.8</mml:mn> <mml:mspace/> <mml:mi>ÎŒ</mml:mi> <mml:msup> <mml:mtext>T/Hz</mml:mtext> <mml:mrow> <mml:mn>1</mml:mn> <mml:mo>/</mml:mo> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> </mml:math> and temperature ${\sim}0.4~\mbox{K/Hz}^{1/2}$ <mml:math xmlns:mml=âhttp://www.w3.org/1998/Math/MathMLâ> <mml:mo>âŒ</mml:mo> <mml:mn>0.4</mml:mn> <mml:mspace/> <mml:msup> <mml:mtext>K/Hz</mml:mtext> <mml:mrow> <mml:mn>1</mml:mn> <mml:mo>/</mml:mo> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> </mml:math> ), spatial resolution (1.3 ÎŒ m), and field of view ( $400 \times 300~\mu \mbox{m}^{2}$ <mml:math xmlns:mml=âhttp://www.w3.org/1998/Math/MathMLâ> <mml:mn>400</mml:mn> <mml:mo>Ă</mml:mo> <mml:mn>300</mml:mn> <mml:mspace/> <mml:mi>ÎŒ</mml:mi> <mml:msup> <mml:mtext>m</mml:mtext> <mml:mn>2</mml:mn> </mml:msup> </mml:math> ). Finally, we use the microscope to obtain images of an integrated cell heater and a PCB, demonstrating its ability in the application of magnetic field and temperature simultaneously imaging at wide-field.