Charge state dynamics of the nitrogen vacancy center in diamond under 1064-nm laser excitation
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2016-07-05 |
| Journal | Physical review. B./Physical review. B |
| Authors | Peng Ji, Meenakshi Dutt |
| Institutions | University of Pittsburgh |
| Citations | 49 |
| Analysis | Full AI Review Included |
6CCVD Technical Analysis & Material Solutions Briefing
Section titled â6CCVD Technical Analysis & Material Solutions BriefingâCharge State Dynamics of the Nitrogen Vacancy Center in Diamond Under 1064 nm Laser Excitation
Section titled âCharge State Dynamics of the Nitrogen Vacancy Center in Diamond Under 1064 nm Laser ExcitationâThis documentation analyzes the key findings, experimental parameters, and methodologies of the research paper concerning the dynamics of NV centers in diamond, and outlines how 6CCVDâs advanced MPCVD materials are ideally suited to replicate, extend, and industrialize this critical quantum research.
Executive Summary
Section titled âExecutive SummaryâThe analyzed research details the charge state dynamics of Nitrogen Vacancy (NV) centers in both bulk Single Crystal Diamond (SCD) and nanodiamonds (NDs) under excitation by a low-power, near-infrared (1064 nm) continuous wave (CW) laser.
- Core Discovery: The 1064 nm IR laser induces photochromism, converting Neutral NV centers (NV0) to Negatively Charged NV centers (NV-). This conversion enhances the critical NV- photoluminescence (PL).
- Methodology: A combination of spectral, time-resolved PL, and Optically Detected Magnetic Resonance (ODMR) was used in a confocal microscope setup to isolate charge state behaviors at both room and cryogenic temperatures (16K).
- Dynamic Regimes: Two distinct time scales were observed: a rapid quenching and recovery (limited by the Acousto-Optic Modulator (AOM) response at $\sim$50 ns) and a slower charge state transfer (in the $\sim\mu$s range).
- Material Requirements: The experiment relied on high-purity, electronic-grade diamond with controlled nitrogen implantation and exceptional thermal contact (achieved via Indium soldering on Copper cold fingers) to minimize thermal drift.
- Quantum Significance: The charge transfer process mediated by the 1064 nm laser was found to be spin-dependent, offering a new mechanism for manipulating the NV center spin state, which is crucial for quantum sensing and information applications.
- 6CCVD Value: The findings necessitate high-quality, ultra-low nitrogen Single Crystal Diamond (SCD) substrates with precise doping and custom surface preparation capabilities, which are 6CCVDâs core expertise.
Technical Specifications
Section titled âTechnical SpecificationsâThe following table extracts critical hard data points and material parameters established during the investigation.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Bulk Diamond Purity ([N]) | < 5 | ppb | Electronic grade starting material (Element Six) |
| N Implantation Energy | 85 | KV | Creating shallow NV layer |
| N Implantation Dose | 1011 / cm2 | N/A | Area dose for NV formation |
| Annealing Temperature | 1000 | °C | Required post-implantation treatment in forming gas |
| NV Center Layer Depth (Target) | $\sim$100 | nm | Below the diamond surface |
| NV Area Density (Estimated) | 10 / ”m2 | N/A | Bulk sample |
| Nanodiamond Diameter | 100 | nm | Commercial sample size |
| Primary Excitation Wavelength (Green) | 532 | nm | Standard NV excitation |
| Charge Conversion Wavelength (IR) | 1064 | nm | CW excitation inducing NV0 $\rightarrow$ NV- |
| Green Laser Power (Typical) | 0.013 - 0.3 | mW | Used for ODMR and charge flipping studies |
| IR Laser Power (Range Tested) | 0 - 30 | mW | Moderate power used for linear rate fitting |
| ODMR Frequency (Ground State) | 2.87 | GHz | Measurement of NV- spin state |
| Slow Charge Flipping Time Scale | $\sim\mu$s | N/A | Exponential decay constant for charge population balance |
| Fast Quenching/Recovery Limit | $\sim$50 | ns | Limited by Acousto-Optic Modulator (AOM) response time |
| Temperature Range | 16 / 295 | K | Cryogenic and Room Temperature operation |
Key Methodologies
Section titled âKey MethodologiesâThe robust observations regarding NV charge dynamics were highly dependent on precise sample fabrication, ultra-pure starting materials, and meticulous thermal management.
- Sample Preparation (Bulk SCD):
- Electronic grade bulk diamond (Nitrogen content < 5 ppb) was selected to minimize background defects.
- Nitrogen implantation was performed at 85 KV to create a shallow NV layer approximately 100 nm below the surface.
- The sample was annealed at 1000 °C in forming gas (N2 and H2) to activate the NV centers.
- Thermal Management:
- Samples (or silicon chips holding NDs) were attached to a high-purity Oxygen-Free Copper (OF-Cu) cold finger using Indium Soldering. This mechanical bond ensured excellent thermal contact, eliminated thermal drift problems, and provided a stable environment for CW 1064 nm laser illumination.
- Optical Setup:
- A confocal microscope was integrated to overlap 532 nm (Green) and 1064 nm (IR) CW lasers.
- A long focal length lens was used specifically in the 1064 nm path to correct chromatic aberration with the high Numerical Aperture (NA 0.9) dry objective.
- Time-Resolved Measurements:
- Acousto-Optic Modulators (AOMs, response time $\sim$50 ns) were utilized for rapid, sub-microsecond switching of both the 532 nm and 1064 nm lasers to resolve the fast quenching dynamics.
- Spin State Manipulation:
- Microwaves (MW) were delivered via a gold-plated tungsten antenna adjacent to the sample to perform Optically Detected Magnetic Resonance (ODMR) measurements, confirming the spin-dependent nature of the charge transfer.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThis research highlights the critical need for defect-engineered, high-purity diamond substrates. 6CCVD is an industry leader in supplying tailor-made MPCVD diamond optimized for quantum and sensing applications, ensuring both material excellence and experimental reliability.
Applicable Materials for Replication and Extension
Section titled âApplicable Materials for Replication and ExtensionâTo replicate the high-fidelity charge transfer studies or explore new regimes (e.g., higher power or temperature variability), 6CCVD recommends:
| Research Requirement | 6CCVD Material Solution | Engineering Value Proposition |
|---|---|---|
| Ultra-Low Nitrogen Purity | Optical Grade Single Crystal Diamond (SCD) | Our SCD growth recipes minimize background nitrogen (< 1 ppb), providing the cleanest possible host lattice for deterministic defect engineering and maximizing spin coherence time. |
| Precise Layer Creation | Custom Ion Implantation Substrates | We offer SCD substrates specifically tailored for post-processing steps (e.g., 85 KV implantation, 1000 °C annealing). We ensure surfaces are atomically smooth (Ra < 1 nm) for stable implantation profiles. |
| Thermal Management & Substrates | Thick SCD & Custom Substrates (up to 10mm) | Diamondâs intrinsic superior thermal conductivity eliminates the need for complex external thermal interfaces (like Indium soldering) used in the paper, especially crucial for scaling high-power CW experiments. |
| Future Boron Studies | Boron-Doped Diamond (BDD) | The paper discusses electron capture from the valence band. 6CCVD offers high-quality BDD (both SCD and PCD forms) ideal for studying charge transfer mechanisms involving engineered donor/acceptor levels. |
Customization Potential for Advanced Quantum Experiments
Section titled âCustomization Potential for Advanced Quantum Experimentsâ6CCVDâs in-house capabilities directly address the complexity and precision required for cutting-edge diamond quantum devices:
- Custom Dimensions: We supply plates and wafers up to 125mm in diameter (PCD) and custom SCD pieces, matching the 3.5mm x 3.5mm bulk sample dimensions used in this study, with thicknesses ranging from 0.1 ”m to 500 ”m.
- High-Quality Polishing: For integration with high-NA objectives and complex optical setups (like the confocal microscope used), our SCD material achieves a surface roughness of Ra < 1 nm. This is essential for minimizing scattering and optical loss.
- Advanced Metalization & Integration: The experiment required sophisticated microwave delivery via a gold-plated tungsten antenna and stable thermal contact. 6CCVD offers in-house custom metalization services (Ti, Pt, Au, W, Cu, Pd) for integration, enabling precise lithographic antenna design and robust electrical/thermal contacts directly on the diamond surface.
Engineering Support & Logistics
Section titled âEngineering Support & Logisticsâ6CCVDâs in-house PhD team can assist with material selection and design consultation for projects involving charge state dynamics, spin-dependent manipulation, and infrared excitation for quantum sensing and optical trapping projects.
We provide global shipping services (DDU default, DDP available) to ensure rapid and secure delivery of custom-engineered diamond solutions to research facilities worldwide.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
The photophysics and charge state dynamics of the nitrogen vacancy (NV) center in diamond has been extensively investigated but is still not fully understood. In contrast to previous work, we find that NV$^{0}$ converts to NV$^{-}$ under excitation with low power near-infrared (1064 nm) light, resulting in $increased$ photoluminescence from the NV$^{-}$ state. We used a combination of spectral and time-resolved photoluminescence experiments and rate-equation modeling to conclude that NV$^{0}$ converts to NV$^{-}$ via absorption of 1064 nm photons from the valence band of diamond. We report fast quenching and recovery of the photoluminescence from $both$ charge states of the NV center under low power 1064 nm laser excitation, which has not been previously observed. We also find, using optically detected magnetic resonance experiments, that the charge transfer process mediated by the 1064 nm laser is spin-dependent.