Control of all the transitions between ground state manifolds of nitrogen vacancy centers in diamonds by applying external magnetic driving fields
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2020-10-21 |
| Journal | Japanese Journal of Applied Physics |
| Authors | Tatsuma Yamaguchi, Yuichiro Matsuzaki, Soya Saijo, Hideyuki Watanabe, Norikazu Mizuochi |
| Institutions | Kyoto University Institute for Chemical Research, National Institute of Advanced Industrial Science and Technology |
| Citations | 5 |
| Analysis | Full AI Review Included |
Technical Documentation: Full Quantum Control of NV Centers in Diamond
Section titled âTechnical Documentation: Full Quantum Control of NV Centers in DiamondâThis document analyzes the research demonstrating full control over the ground state manifolds of Nitrogen Vacancy (NV) centers using external magnetic driving fields. This breakthrough simplifies the realization of NV-based quantum technologies by eliminating the need for complex mechanical or electrical fabrication schemes.
Executive Summary
Section titled âExecutive SummaryâThis research validates a simplified, room-temperature method for achieving full coherent control of the three ground state sublevels (|0>, |B>, |D>) of the NV center spin-1 system in diamond.
- Full Coherent Control: Demonstrated control of all three possible transitions (|0> to |B>, |0> to |D>, and |B> to |D>) using a combination of Microwave (MW) and Radio Frequency (RF) pulses.
- Simplified Methodology: The scheme operates at room temperature and atmospheric pressure, requiring only external AC magnetic driving fields, eliminating the need for complex diamond fabrication (e.g., mechanical resonators or integrated electric field gates).
- Orthogonal Field Application: Control is enabled by applying a DC magnetic field orthogonal to the NV axis, which lifts the degeneracy and allows the critical |B> to |D> transition to be driven by RF pulses.
- Observed Coherence: Clear Rabi oscillations were observed for all three transitions, confirming coherent manipulation of the spin states.
- Quantum Technology Enabler: This technique significantly simplifies the path toward practical, scalable implementation of NV centers for quantum information processing and high-sensitivity quantum sensing (magnetic fields, temperature).
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the experimental results, focusing on the frequencies and pulse parameters required for coherent control.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| NV System | Spin-1 | N/A | Ground state manifold control |
| Operating Environment | Room | Temperature | Simplified, practical application |
| MW Resonance Frequency ( | 0> to | B>) | 2.8768 |
| MW Resonance Frequency ( | 0> to | D>) | 2.8847 |
| RF Resonance Frequency ( | B> to | D>) | ~7.9 |
| MW Ď Pulse Duration | ~210 | ns | Confirmed Ď rotation for |
| Control Method | External AC Magnetic | Fields | MW and RF pulses |
| Required DC Field Orientation | Orthogonal | N/A | Relative to the specific NV axis |
Key Methodologies
Section titled âKey MethodologiesâThe experiment successfully achieved full quantum control by leveraging specific magnetic field geometries and pulse sequences.
- Material Selection: An ensemble of NV centers within a diamond sample (previously characterized in Ref. [34]) was used.
- Axis Isolation: A DC magnetic field was applied orthogonal to one of the four crystallographic NV axes. This lifted the degeneracy, allowing the target NV axis to be addressed selectively via frequency.
- Initialization: NV centers were initialized into the |0> state using a green laser pulse.
- MW Control: Resonant Microwave (MW) pulses were used to drive the transitions between the |0> state and the |B> or |D> states.
- RF Control: Resonant Radio Frequency (RF) pulses (at approximately 2Ex frequency) were used to drive the coherent transition between the |B> and |D> statesâa transition typically inaccessible via AC magnetic fields in parallel-field setups.
- Readout: The spin state was detected using optical measurements (Optically Detected Magnetic Resonance, ODMR).
- Coherence Confirmation: Rabi oscillations were measured by sweeping the duration of both MW and RF pulses, confirming coherent manipulation across all three ground state transitions.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThe successful implementation of NV-based quantum control relies fundamentally on the quality and purity of the diamond substrate. 6CCVD specializes in providing the high-specification MPCVD diamond required to replicate, scale, and advance this research toward commercial quantum devices.
Applicable Materials for NV Quantum Control
Section titled âApplicable Materials for NV Quantum ControlâTo achieve the long coherence times and high signal contrast necessary for quantum information processing and sensing, researchers require Optical Grade Single Crystal Diamond (SCD) with tightly controlled impurity levels.
| 6CCVD Material Solution | Specification | Application Relevance |
|---|---|---|
| Optical Grade SCD | Nitrogen concentration < 5 ppb (typical) | Maximizes T2 and T2* coherence times, crucial for quantum memory and sensing. |
| Custom NV Creation | Controlled N doping or post-growth implantation | Enables precise control over NV density, supporting both ensemble (high signal) and single-NV (high spatial resolution) experiments. |
| Ultra-Polished SCD | Surface Roughness (Ra) < 1 nm | Essential for minimizing surface-related decoherence, particularly critical for shallow NV centers used in external sensing. |
| Thick Substrates | Up to 10 mm thick | Provides robust thermal management and mechanical stability for complex quantum setups. |
Customization Potential for Device Integration
Section titled âCustomization Potential for Device IntegrationâThe experimental setup requires precise delivery of MW and RF fields, often achieved through integrated circuitry on the diamond surface. 6CCVD offers comprehensive fabrication services to transition from raw material to functional quantum substrate.
- Custom Dimensions: 6CCVD provides SCD plates and wafers in custom sizes and shapes, ensuring seamless integration into existing experimental apparatus.
- Advanced Metalization: We offer in-house deposition and patterning of thin-film metal stacks (e.g., Ti/Pt/Au, W/Cu) necessary for creating high-frequency coplanar waveguides (CPWs) directly on the diamond surface for efficient MW/RF pulse delivery.
- Precision Machining: Custom laser cutting and etching services are available for creating microstructures, alignment features, or specific geometries required for optical coupling or integration with external components.
Engineering Support
Section titled âEngineering Supportâ6CCVDâs in-house team of PhD material scientists and engineers are experts in optimizing MPCVD growth recipes for quantum applications. We provide consultation on:
- Material Selection: Assisting researchers in selecting the optimal diamond grade (e.g., high-purity SCD vs. Boron-Doped Diamond (BDD) for electrochemical applications) based on specific project requirements (e.g., maximizing T2 or achieving high NV density).
- Defect Engineering: Tailoring growth parameters to control the concentration and depth of NV centers for both ensemble and single-NV sensing projects.
- Surface Preparation: Ensuring the required surface termination and roughness (Ra < 1 nm) for subsequent lithography and device fabrication steps.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Abstract We demonstrate control of all the three transitions among the ground state sublevels of NV centers by applying magnetic driving fields. To address the states of a specific NV axis among the four axes, we apply a magnetic field orthogonal to the NV axis. We control two transitions by microwave pulses and the remaining transition by radio frequency (RF) pulses. In particular, we investigate the dependence of Rabi oscillations on the frequency and intensity of the RF pulses. In addition, we perform a Ď pulse by the RF pulses and measured the coherence time between the ground state sublevels. Our results pave the way for control of NV centers for the realization of quantum information processing and quantum sensing.