An efficient fluorescent single-particle position tracking system for long-term pulsed measurements of nitrogen-vacancy centers in diamond
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2018-02-01 |
| Journal | Review of Scientific Instruments |
| Authors | Kiho Kim, Jiwon Yun, Donghyuck Lee, Dohun Kim |
| Institutions | Seoul National University |
| Citations | 3 |
| Analysis | Full AI Review Included |
6CCVD Technical Documentation: Long-Term Quantum Tracking in MPCVD Diamond
Section titled â6CCVD Technical Documentation: Long-Term Quantum Tracking in MPCVD DiamondâExecutive Summary
Section titled âExecutive SummaryâThis research validates the critical role of high-purity single-crystal diamond (SCD) substrates in achieving stable, ultra-long-term quantum measurements using Nitrogen-Vacancy (NV) centers. The developed system enables real-time 3D position tracking of single NV centers, essential for leveraging diamondâs exceptional spin coherence in quantum technologies.
- Material Foundation: Confirms bulk SCD diamond (Quantum Grade Type IIa) as the necessary platform for stable, long-term NV center quantum sensing and computing applications.
- Stability Achieved: Demonstrates continuous 3D position stabilization and photon counting for single/few NV centers over $\ge 10$ hours, minimizing photon count RMS variation to $\lt 5$%.
- Quantum Measurement Validation: Enables simultaneous, high-resolution quantum measurements, including pulsed Optically Detected Magnetic Resonance (ODMR) and coherent Rabi oscillations (clear $8\ \text{MHz}$ frequency).
- High Sensitivity Tracking: System maintains lock even for low-photon-collection-efficiency centers, tracking signal rates down to $10^{3}\ \text{s}^{-1}$.
- Minimal Perturbation: Tracking requires minimal position modulation, typically $10\ \text{nm}$, ensuring stability during sensitive quantum spin manipulation sequences.
- Rapid Drift Compensation: Achieves fast position error recovery, with an upper bound response time of $0.9\ \text{s}$ following a significant $250\ \text{nm}$ step-like positional shift.
- Replication Basis: Results rely on NV center creation via $20\ \text{keV}$ ion implantation and $700^\circ\text{C}$ annealing into the bulk Type IIa diamond substrate.
Technical Specifications
Section titled âTechnical SpecificationsâThe core performance metrics and material preparation parameters extracted from the research paper are summarized below:
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Tracking Duration (Stable) | $\ge 10$ | hours | Single NV Center in Type IIa Bulk Diamond |
| Maximum Drift (X/Y/Z) | $\pm 200 / \pm 100 / \pm 50$ | nm | Measured over 30 hours (uncorrected) |
| Position Modulation Radius | $10 - < 20$ | nm | Applied during feedback for spatial derivative measurement |
| Minimum Photon Count Tracked | $10^{3}$ | s-1 | Low-efficiency single NV center |
| Position Error Recovery Time | $0.9$ | s | Upper bound for $250\ \text{nm}$ step shift (X-axis) |
| Negative Feedback Gain | $\times 100$ | N/A | Fixed setting on NanoTrak controller |
| Rabi Frequency Measured | $8$ | MHz | High-resolution coherent spin oscillation |
| Nitrogen Implantation Energy | 20 | keV | Used to create NV defects |
| Nitrogen Implantation Dose | $5 \times 10^{10}$ | cm-2 | NV concentration increase in bulk diamond |
| Annealing Temperature/Duration | $700$ / $3$ | °C / hours | Thermal activation of NV centers |
| Green Excitation Laser Power | 200 | mW | Continuous Wave (CW) $532\ \text{nm}$ |
Key Methodologies
Section titled âKey MethodologiesâThe experiment successfully combined standard quantum optics techniques with commercially available, high-speed feedback components to achieve unprecedented tracking stability.
Sample Preparation and Fabrication Recipe
Section titled âSample Preparation and Fabrication Recipeâ- Substrate Selection: Utilized Quantum Grade Type IIa bulk diamond (low native nitrogen concentration).
- Ion Implantation: Nitrogen ions implanted at an accelerating voltage of $20\ \text{keV}$ at a dose of $5 \times 10^{10}\ \text{cm}^{-2}$ to establish controlled NV center concentration near the surface.
- Annealing: Post-implantation thermal treatment performed at $700^\circ\text{C}$ for $3$ hours to activate the NV centers (vacancy creation/migration).
Position Feedback and Tracking Parameters
Section titled âPosition Feedback and Tracking Parametersâ- Detection System: Confocal setup using single-photon counting modules (APDs) in a Hanbury-Brown-Twiss configuration for $g^{(2)}(\tau)$ measurements.
- Position Modulation: Sinusoidal modulation applied via piezo stage inputs:
- X-Y Axis: Circular modulation at $\sim 25\ \text{Hz}$ (sine/cosine waves with $90^\circ$ phase shift).
- Z Axis: Sine wave modulation at $\sim 35\ \text{Hz}$.
- Feedback Mechanism: Phase-sensitive detection (lock-in) measures the spatial derivative of the photon intensity, which is then fed back to the piezo stage via a NanoTrak controller.
- Feedback Rate Limit: The system update time is constrained by the $1\ \text{ms}$ photon detection time and $2\ \text{ms}$ D/A update time of the SR400 counter, limiting the overall feedback rate to less than $\sim 50\ \text{Hz}$.
- Quantum Measurement Integration: Position tracking signals were split to run simultaneously with quantum measurements (e.g., pulsed ODMR and Rabi oscillations) using a dedicated gated high-speed photon counter (SR400) or time-correlated single-photon counter (TimeHarp).
6CCVD Solutions & Capabilities: Precision Diamond for Quantum Applications
Section titled â6CCVD Solutions & Capabilities: Precision Diamond for Quantum ApplicationsâThe findings underscore the necessity of high-quality, ultra-low-defect diamond substrates for robust quantum technology platforms. 6CCVD is an industry leader in supplying the exact specifications required to replicate and advance this research globally.
Applicable Materials
Section titled âApplicable MaterialsâTo replicate or extend the long-term stable tracking and ODMR measurements described, researchers require SCD with superior material properties.
| Research Requirement | 6CCVD Recommended Material | Technical Justification (Sales Focus) |
|---|---|---|
| Quantum Grade IIa Bulk Diamond | Optical Grade Single Crystal Diamond (SCD) | Our MPCVD growth process yields SCD with nitrogen content below $1\ \text{ppb}$, ensuring maximum NV center spin coherence ($\text{T}_2$) necessary for high-resolution Rabi oscillations. |
| Nanodiamond Preparation | Polycrystalline Diamond (PCD) Precursor | 6CCVD offers high-purity PCD and micro/nanodiamond feedstock necessary for high-volume NV center nanoparticle development and bio-sensing applications. |
| Substrate Integrity | SCD Substrates up to $500\ \mu\text{m}$ Thick | Provides the mechanical and thermal stability required to withstand $700^\circ\text{C}$ annealing post-implantation and minimize drift caused by microwave heating. |
Customization Potential
Section titled âCustomization PotentialâThe experimental setup utilized a specific sample size ($5\ \text{mm} \times 5\ \text{mm}$) and required the integration of a microwave cable and Printed Circuit Board (PCB) adjacent to the diamond surface. 6CCVD offers integrated engineering solutions to streamline device fabrication:
- Precision Dimensioning: We provide custom SCD and PCD dimensions up to $125\ \text{mm}$ wafers, cut precisely via advanced laser techniques to fit existing confocal or cryogenic setups.
- Ultra-Smooth Polishing: Ion implantation and subsequent optical collection stability rely on optimal surface quality. 6CCVD guarantees SCD polishing to $\text{Ra} \lt 1\ \text{nm}$, minimizing optical scattering loss and stabilizing the NV point spread function.
- Integrated Microwave Circuitry: The paper notes manual attachment of a $100\ \mu\text{m}$ gold wire. 6CCVD eliminates this manual step by offering in-house custom metalization services (Au, Pt, Ti, Cu, W) for fabricating lithographically defined coplanar waveguides (CPWs) directly onto the SCD surface, improving microwave field homogeneity and reproducibility for pulsed ODMR experiments.
Engineering Support & Global Access
Section titled âEngineering Support & Global Accessâ6CCVDâs in-house PhD engineering team possesses deep expertise in MPCVD diamond growth tailored for quantum manipulation research. We assist clients in optimizing material selection parameters, including:
- Determining optimal SCD crystal orientation (e.g., [100] vs. [111]) for specific NV alignment and magnetic field sensing geometries.
- Consultation on surface termination and material purity requirements to maximize $T_2$ and $T_{2}^*$ coherence times for stable Rabi and ODMR experiments.
- Logistical support for researchers globally with DDU default and DDP global shipping capabilities, ensuring rapid delivery of high-value SCD substrates.
Call to Action
Section titled âCall to ActionâFor custom specifications, consultation on ion implantation substrates, or integrated metalization services for long-term NV center quantum projects, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
A simple and convenient design enables real-time three-dimensional position tracking of nitrogen-vacancy (NV) centers in diamond. The system consists entirely of commercially available components (a single-photon counter, a high-speed digital-to-analog converter, a phase-sensitive detector-based feedback device, and a piezo stage), eliminating the need for custom programming or rigorous optimization processes. With a large input range of counters and trackers combined with high sensitivity of single-photon counting, high-speed position tracking (upper bound recovery time of 0.9 s upon 250 nm of step-like positional shift) not only of bright ensembles, but also of low-photon-collection-efficiency single to few NV centers (down to 103 sâ1) is possible. The tracking requires position modulation of only 10 nm, which allows simultaneous position tracking and pulsed measurements in the long term. Therefore, this tracking system enables measuring a single-spin magnetic resonance and Rabi oscillations at a very high resolution even without photon collection optimization. The system is widely applicable to various fields related to NV center quantum manipulation research such as NV optical trapping, NV tracking in fluid dynamics, and biological sensing using NV centers inside a biological cell.