Temperature Selective Thermometry with Sub‐Microsecond Time Resolution Using Dressed‐Spin States in Diamond
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2021-09-16 |
| Journal | Advanced Quantum Technologies |
| Authors | Jiwon Yun, Kiho Kim, Sungjoon Park, Dohun Kim |
| Institutions | Seoul National University |
| Citations | 6 |
| Analysis | Full AI Review Included |
Temperature Selective Thermometry using Dressed-Spin States in Diamond: Technical Analysis and 6CCVD Solutions
Section titled “Temperature Selective Thermometry using Dressed-Spin States in Diamond: Technical Analysis and 6CCVD Solutions”This document analyzes the research paper “Temperature selective thermometry with sub-microsecond time resolution using dressed-spin states in diamond” and outlines how 6CCVD’s advanced MPCVD diamond materials and fabrication capabilities can support and extend this critical quantum sensing research.
Executive Summary
Section titled “Executive Summary”This research successfully demonstrates a novel, highly selective, and high-speed nanoscale thermometry technique using Nitrogen-Vacancy (NV) centers in diamond. The core value proposition and technical achievements are summarized below:
- Novel Thermometry Scheme: Utilizes microwave-dressed spin states (DS-ODMR) in NV centers to achieve temperature selectivity, decoupling the measurement from magnetic field fluctuations.
- Exceptional Temporal Resolution: Achieved a time resolution of 48 ns, enabling the characterization of fast, transient thermal processes in nanoelectronic devices.
- High Sensitivity and Precision: Demonstrated a thermal sensitivity of 3.7 K·Hz-1/2 and a temperature precision of 0.6 K.
- Magnetic Field Robustness: The method is robust against external magnetic field fluctuations up to 2 G, making it ideal for sensing in complex environments (e.g., near current-carrying wires or in biological systems).
- Spatiotemporal Imaging: Successfully measured transient temperature changes (approx. 5 K) induced by pulsed microwave heating on a gold Coplanar Waveguide (CPW).
- Material Basis: The experiment relied on ensemble NV centers in 100 nm nanodiamonds and Type-Ib bulk diamond for validation.
Technical Specifications
Section titled “Technical Specifications”The following hard data points were extracted from the experimental results and methodology:
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Temporal Resolution | 48 | ns | Limited by 3-bin box averaging of time-tagged photon counts. |
| Thermal Sensitivity (ηT) | 3.7 | K·Hz-1/2 | Achieved using NV ensemble (above shot-noise limit of 2.5 K·Hz-1/2). |
| Temperature Precision | 0.6 | K | Root-mean-squared (RMS) temperature fluctuation. |
| **Magnetic Field Robustness (δ | B | )** | 2 |
| NV Center Material | 100 | nm | Average diameter of nanodiamonds (ensemble). |
| Heating Microwave Power | 48 | dBm | Used for 3 µs pulse heating at 2.8 GHz carrier frequency. |
| Probe Microwave Power | 18 | dBm | Approximately 30 dB weaker than heating power. |
| Spatial Resolution (Evaluated) | 10 | µm | Distance between nanodiamond ensembles. |
| Zero-Field Splitting Sensitivity (dD/dT) | 74 | kHz·K-1 | Near 300 K (Room Temperature). |
| DS-ODMR Linewidth (Γ) | 11.5 | MHz | Used for six-point measurement method. |
| Convective Heat Transfer (hconvection) | 2 x 108 | W·m-2·K-1 | Fitted value used in numerical simulations. |
Key Methodologies
Section titled “Key Methodologies”The time-resolved, magnetic-field-robust thermometry was achieved through a combination of quantum control and advanced measurement sequences:
- Dressed Spin State Basis: Two simultaneous microwaves (MW1, MW2) were applied, resonant to the $|0\rangle \leftrightarrow |\pm 1\rangle$ transitions, to move the NV center into a dressed spin state basis. This basis ensures the temperature-induced frequency shift (δD) is decoupled from external magnetic field fluctuations (δB).
- Experimental Setup: Experiments were conducted using a homebuilt confocal microscope, a 532 nm green laser for continuous Photoluminescence (PL) readout, and a 3-axis stage neodymium magnet for external field application.
- Microwave Heating: Transient temperature changes were induced by a high-power (48 dBm), 3 µs microwave pulse applied to a gold Coplanar Waveguide (CPW) fabricated on a cover glass substrate.
- Pump-Probe Sequence: A continuous measurement sequence was implemented over a 60 µs period, synchronized with the heating pulse, using the frequency modulation mode of signal generators.
- Six-Point Measurement Method: To extract the center frequency (favg) robustly against fluctuations in fluorescence contrast and linewidth (Γ), six distinct microwave frequencies (fA to fF) were measured sequentially using a time-tagged photon counting module (16 ns bins).
- Temperature Conversion: The measured photon counts (PA to PF) were converted into temperature change (δT) using a derived formula (Equation 5), which incorporates the fixed detuning (dω) and the known dD/dT sensitivity.
6CCVD Solutions & Capabilities
Section titled “6CCVD Solutions & Capabilities”6CCVD is uniquely positioned to supply the high-quality MPCVD diamond materials and custom fabrication required to replicate, optimize, and scale this advanced quantum thermometry research.
| Research Requirement | 6CCVD Solution & Capability | Technical Advantage for Quantum Sensing |
|---|---|---|
| High-Purity Diamond Host (Type-Ib bulk diamond used) | Optical Grade Single Crystal Diamond (SCD) | Provides the lowest strain environment (Ra < 1 nm polishing) and highest purity (low native nitrogen) for maximizing NV center coherence time (T2*) and thermal stability. Ideal for single-NV studies. |
| Large Area Thermometry (Ensemble NV centers for imaging) | High-Quality Polycrystalline Diamond (PCD) Wafers | Available in custom dimensions up to 125 mm diameter. Enables scaling of the DS-ODMR method for chip-scale temperature imaging applications. Polishing available to Ra < 5 nm. |
| Integrated CPW Structure (Gold CPW on glass substrate) | Custom Metalization Services | In-house deposition of thin-film metals (Au, Pt, Pd, Ti, W, Cu) directly onto SCD or PCD substrates. Integrating the CPW directly onto the diamond eliminates thermal barriers and improves microwave coupling efficiency. |
| Substrate Optimization (Thermal management) | Custom Thickness Diamond Plates/Wafers | SCD and PCD films available from 0.1 µm to 500 µm, and substrates up to 10 mm thick. Allows researchers to precisely control the thermal mass and heat dissipation characteristics of the sensing platform. |
| NV Center Engineering (Material selection) | Expert Engineering Support | Our in-house PhD team assists with material selection, including optimizing diamond growth parameters for specific NV density requirements (e.g., high-density ensembles for imaging or low-density for single-NV studies) required for time-resolved nanoscale quantum sensing. |
6CCVD Material Recommendations for Replication and Extension:
- For Single-NV Validation: Utilize Optical Grade SCD wafers (0.1 µm to 500 µm thickness) with ultra-low surface roughness (Ra < 1 nm) to ensure maximum spin coherence and minimal surface noise.
- For Large-Scale Imaging: Utilize High-Quality PCD plates (up to 125 mm) as a robust, large-area platform for dispersing nanodiamonds or implanting NV ensembles for 2D temperature mapping.
- For Integrated Devices: Order custom SCD or PCD substrates with Ti/Pt/Au metalization for direct fabrication of high-performance Coplanar Waveguides (CPWs) or micro-antennas.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly. We offer global shipping (DDU default, DDP available) to ensure rapid delivery of your specialized diamond materials.
View Original Abstract
Abstract Versatile nanoscale sensors that are susceptible to changes in a variety of physical quantities often exhibit limited selectivity. This paper reports a novel scheme based on microwave‐dressed spin states for optically probed nanoscale temperature detection using diamond quantum sensors, which provides selective sensitivity to temperature changes. By combining this scheme with a continuous pump-probe scheme using ensemble nitrogen‐vacancy centers in nanodiamonds, a sub‐microsecond temporal resolution with thermal sensitivity of 3.7 that is insensitive to variations in external magnetic fields on the order of 2 G is demonstrated. The presented results are favorable for the practical application of time‐resolved nanoscale quantum sensing, where temperature imaging is required under fluctuating magnetic fields.