Widefield Diamond Quantum Sensing with Neuromorphic Vision Sensors
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2023-11-08 |
| Journal | Advanced Science |
| Authors | Zhiyuan Du, Madhav Gupta, Feng Xu, Kai Zhang, Jiahua Zhang |
| Institutions | Nano and Advanced Materials Institute, University of Hong Kong |
| Citations | 9 |
| Analysis | Full AI Review Included |
Technical Analysis: Widefield Diamond Quantum Sensing with Neuromorphic Vision Sensors
Section titled âTechnical Analysis: Widefield Diamond Quantum Sensing with Neuromorphic Vision SensorsâThis document analyzes the research paper detailing the use of neuromorphic vision sensors (event cameras) for high-speed, widefield Optically Detected Magnetic Resonance (ODMR) quantum sensing using Nitrogen Vacancy (NV) centers in diamond. The analysis highlights the technical achievements and connects the material requirements directly to 6CCVDâs advanced MPCVD diamond capabilities.
Executive Summary
Section titled âExecutive SummaryâThe research successfully demonstrates a novel approach to widefield quantum sensing by replacing traditional frame-based cameras with neuromorphic event cameras, overcoming critical data bottlenecks inherent in dynamic ODMR measurements.
- 13x Temporal Resolution Improvement: The event-based method achieved a sensing time of 0.14 s, a 13-fold improvement over the state-of-the-art frame-based EMCCD approach (1.82 s).
- Comparable Precision: High sensing precision was maintained, with the event-based ODMR yielding 0.034 MHz precision, comparable to the 0.031 MHz achieved by the slower frame-based method.
- Data Compression & Low Latency: The neuromorphic sensor pre-processes data near the sensor, resulting in massive data volume reduction (35 MB down to 363 KB) and significantly lower latency (26 ms down to 220 ”s).
- Dynamic Thermometry: The technique was successfully deployed to monitor sub-second scale laser heating of gold nanoparticles (AuNPs) coated on the diamond surface, demonstrating 0.28 s temporal resolution and 0.5 K temperature precision.
- Material Requirement: The experiment relied on high-quality, single-crystalline CVD diamond with uniform NV center distribution and a highly polished surface for subsequent AuNP functionalization.
- Future Potential: The methodology paves the way for intelligent quantum sensors by enabling integration with advanced in-sensor processing and memory devices.
Technical Specifications
Section titled âTechnical SpecificationsâThe following table summarizes the key performance metrics and material parameters extracted from the experimental results (Table 1 and Figure 3G).
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Sensing Time (Event-Based) | 0.14 | s | Total time for ODMR sweep (forward/backward) |
| Sensing Time (Frame-Based) | 1.82 | s | Total time for ODMR sweep (EMCCD) |
| Precision (Event-Based ODMR) | 0.034 | MHz | Standard deviation of extracted resonance frequency |
| Precision (Frame-Based ODMR) | 0.031 | MHz | Standard deviation of extracted resonance frequency |
| Data Amount (Event-Based) | 363 | KB | Highly compressed data volume |
| Data Amount (Frame-Based) | 35 | MB | Massive data volume bottleneck |
| Latency (Event-Based) | 220 | ”s | Near-sensor processing |
| Latency (Frame-Based) | 26 | ms | Limited by readout and transfer |
| Spatial SBR (SBR) | 194 | N/A | Signal-to-Background Ratio (Event-Based) |
| Dynamic Range | 120 | dB | Event camera capability |
| Temperature Resolution | 0.28 | s | Temporal resolution for dynamic thermometry |
| Temperature Precision | < 0.5 | K | Static measurement precision |
| Diamond Material | Single Crystal CVD | N/A | <100> orientation, P2 grade |
| NV Concentration (Estimated) | 670 | ”m-3 | Uniform distribution |
Key Methodologies
Section titled âKey MethodologiesâThe experiment successfully integrated advanced MPCVD diamond material with novel neuromorphic sensing technology.
- Diamond Substrate Preparation: Single-crystalline bulk CVD diamond (3.0 x 3.0 x 0.25 mm, <100> orientation) with a uniform distribution of NV centers (estimated 670 ”m-3) was used.
- Surface Functionalization: The diamond surface was chemically activated (piranha solution) and functionalized using BTSE, TEOS, and APTES. A layer of positively charged silica was coated to facilitate the electrostatic adsorption of negatively charged gold nanoparticles (AuNPs).
- ODMR Setup: A widefield quantum diamond microscope was employed, using a 532 nm CW laser for NV excitation and a custom microwave (MW) system for spin state manipulation.
- MW Frequency Sweep: MW signals were generated by mixing fixed (f1 = 2835 MHz) and swept (f2: 1 to 70 MHz) frequencies.
- Frame-Based Benchmark: Measurements used an Electron Multiplying Charged Coupled Device (EMCCD) camera with a discrete MW sweep (70 points, 26 ms exposure per frame) totaling 1.82 s per ODMR cycle.
- Event-Based Measurement: Measurements used a neuromorphic event camera (Prophesee EVK1-Gen3.1 VGA) with a continuous linear chirp MW sweep (70 ms period, 10 loops stacked). The camera converts fluorescence intensity changes into sparse âspikesâ or events.
- Dynamic Thermometry Setup: An additional 637 nm red laser was introduced for heating the AuNP-coated surface. The heating power was modulated by an electrically-rotated linear polarizer to achieve continuous cosine square temperature dynamics.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & Capabilitiesâ6CCVD is uniquely positioned to supply the high-quality MPCVD diamond substrates required to replicate and advance this cutting-edge neuromorphic quantum sensing research. Our capabilities ensure material quality, dimensional precision, and necessary surface preparation for integrated quantum devices.
| Research Requirement | 6CCVD Solution & Capability | Technical Advantage for Quantum Sensing |
|---|---|---|
| High-Purity SCD Platform | Optical Grade Single Crystal Diamond (SCD) | We supply SCD wafers (0.1 ”m to 500 ”m thick) with ultra-low strain and controlled nitrogen incorporation, essential for maximizing NV center coherence time (T2) and achieving high quantum sensing precision. |
| Custom Dimensions & Scaling | Plates/Wafers up to 125 mm | The paper used a small 3x3x0.25 mm sample. 6CCVD provides custom dimensions and can scale up substrates to 125 mm (PCD) or large SCD plates, facilitating the development of larger-FOV, high-throughput widefield sensors. |
| Uniform NV Concentration | Tailored MPCVD Growth Recipes | Our in-house MPCVD expertise allows for precise control over nitrogen doping, ensuring the uniform NV concentration (e.g., 670 ”m-3) and depth required for consistent widefield ODMR signal across the entire field of view. |
| Ultra-Smooth Surface for AuNP Deposition | Advanced Polishing (Ra < 1 nm) | We guarantee SCD surfaces with roughness (Ra) below 1 nm. This ultra-smooth finish is critical for reliable, uniform deposition of gold nanoparticles (AuNPs) and subsequent chemical functionalization steps used in the thermometry application. |
| Integrated Heating Elements | Custom Metalization Services | While the paper used AuNPs for heating, 6CCVD offers internal metalization capabilities (Au, Pt, Ti, W, Cu). This allows researchers to integrate patterned metal heating elements or microwave antennas directly onto the diamond surface for enhanced device performance and stability. |
| Global Research Support | In-House PhD Engineering Team | Our technical sales engineers and PhD material scientists are available to consult on optimizing diamond specifications (e.g., NV density, surface termination, substrate thickness) to maximize the Signal-to-Background Ratio (SBR) and temporal resolution for high-speed neuromorphic ODMR projects. |
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Abstract Despite increasing interest in developing ultrasensitive widefield diamond magnetometry for various applications, achieving high temporal resolution and sensitivity simultaneously remains a key challenge. This is largely due to the transfer and processing of massive amounts of data from the frameâbased sensor to capture the widefield fluorescence intensity of spin defects in diamonds. In this study, a neuromorphic vision sensor to encode the changes of fluorescence intensity into spikes in the optically detected magnetic resonance (ODMR) measurements is adopted, closely resembling the operation of the human vision system, which leads to highly compressed data volume and reduced latency. It also results in a vast dynamic range, high temporal resolution, and exceptional signalâtoâbackground ratio. After a thorough theoretical evaluation, the experiment with an offâtheâshelf event camera demonstrated a 13Ă improvement in temporal resolution with comparable precision of detecting ODMR resonance frequencies compared with the stateâofâtheâart highly specialized frameâbased approach. It is successfully deploy this technology in monitoring dynamically modulated laser heating of gold nanoparticles coated on a diamond surface, a recognizably difficult task using existing approaches. The current development provides new insights for highâprecision and lowâlatency widefield quantum sensing, with possibilities for integration with emerging memory devices to realize more intelligent quantum sensors.