Coherent electrical control of single electron spin in diamond nitrogen-vacancy center
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2022-01-01 |
| Journal | Acta Physica Sinica |
| Authors | Jiandong Wu, Cheng Zhi, Xiangyu Ye, Zhaokai Li, Pengfei Wang |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Coherent Electrical Control of NV Centers
Section titled âTechnical Documentation & Analysis: Coherent Electrical Control of NV Centersâ6CCVD Reference Document: QCC-APS-71-117601 (2022) Application Focus: Solid-State Quantum Computing, Electrometry, and Quantum Sensing
Executive Summary
Section titled âExecutive SummaryâThis research successfully demonstrates the coherent electrical control of single electron spins in near-surface Nitrogen-Vacancy (NV) centers in diamond, a critical step for integrating quantum systems with classical semiconductor technology.
- Core Achievement: Direct observation of electrically driven Rabi oscillations (ERabi) between the magnetic-dipole forbidden $|m_s = -1\rangle$ and $|m_s = +1\rangle$ states ($\Delta m_s = \pm 2$).
- Material Requirement: The experiment relied on high-purity, 12C purified CVD diamond to achieve a long electron spin coherence time (T2 = 1.6 ms).
- Methodology: Utilized custom-fabricated surface gold electrodes (10 ”m gap) to apply an alternating electric field, enabling Electrically Driven Optically Detected Magnetic Resonance (EODMR).
- Control Mechanism: The ERabi oscillation frequency was found to be linearly dependent on the square root of the driving electric field power ($\sqrt{W}$), confirming precise control.
- Technological Impact: Combining electrical and magnetic control allows for full manipulation of all three NV spin levels, accelerating the development of compact, solid-state quantum devices and high-resolution electrometers.
- Scaling Potential: The authors note that integrating electrodes within the diamond bulk (leveraging diamondâs high breakdown voltage of 21.5 MV/cm) could increase control speed by 2-3 orders of magnitude.
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the experimental results and material preparation details:
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Diamond Growth Method | CVD | N/A | Chemical Vapor Deposition |
| Carbon Purity | 99.999% | 12C | Required for long T2 |
| Ion Implantation Species | 15N | N/A | NV Center Creation |
| Ion Implantation Energy | 2.5 | keV | Creates near-surface NVs |
| NV Center Depth | ~5 | nm | Enhanced electric field coupling |
| Electron Spin Coherence Time (T2) | 1.6 | ms | Measured via exponential decay fit |
| Zero-Field Splitting (D) | 2.87 | GHz | NV Ground State Triplet |
| Applied Axial Magnetic Field (Bz) | 181.47 | G | Used for Zeeman splitting |
| Electric Field Resonance Frequency | 1019.3 | MHz | Drives $ |
| Electrode Gap | 10 | ”m | Distance between surface Au electrodes |
| Electrode Material | Gold (Au) | N/A | Metalization layer |
| Fastest $\pi$-Pulse Time | 6.65 | ”s | Achieved at 0.28 W power |
Key Methodologies
Section titled âKey MethodologiesâThe experiment successfully combined advanced diamond material engineering with micro-fabrication and quantum optical measurement techniques:
- High-Purity CVD Growth: Diamond material was grown using CVD, followed by ultra-high 12C purification to minimize spin decoherence caused by nuclear spin bath noise.
- Near-Surface NV Creation: 15N ion implantation at 2.5 keV was used to position the NV centers approximately 5 nm below the surface, maximizing coupling to the external electric field.
- Micro-Fabrication of Electrodes: Custom gold (Au) electrodes, approximately 100 nm thick, were fabricated on the diamond surface with a precise 10 ”m gap to generate the alternating electric field (Eâ„).
- ODMR Setup: An Optically Detected Magnetic Resonance (ODMR) system, utilizing a 532 nm laser, was used for NV spin initialization (to $|m_s = 0\rangle$) and subsequent fluorescence readout.
- EODMR Pulse Sequence: A sequence involving laser initialization, a microwave $\pi$-pulse (to $|m_s = -1\rangle$), an electric field pulse (PE) of variable duration, and a final readout pulse was used to observe ERabi oscillations.
- Coherent Control Measurement: The periodic change in fluorescence count rate as a function of the electric field pulse duration ($\tau$) was measured and fitted to a damped sinusoid to quantify the ERabi frequency and control speed.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & Capabilitiesâ6CCVD is uniquely positioned to supply the specialized diamond materials and fabrication services required to replicate and advance this research in coherent electrical spin control.
Applicable Materials
Section titled âApplicable MaterialsâTo achieve the long coherence times (T2 = 1.6 ms) necessary for high-fidelity quantum operations, the following 6CCVD material is essential:
| 6CCVD Material | Specification | Application Relevance |
|---|---|---|
| Optical Grade SCD | Ultra-low strain, high crystalline quality, high 12C purity (up to 99.999%). | Provides the stable quantum host environment required for long T2 coherence times in NV centers. |
| Custom SCD Substrates | Thicknesses available from 0.1 ”m up to 500 ”m. | Ideal for creating thin membranes or bulk substrates suitable for subsequent ion implantation and micro-machining. |
Customization Potential
Section titled âCustomization PotentialâThe research highlights the need for precise surface engineering and metalization, areas where 6CCVD offers comprehensive in-house capabilities:
- Custom Metalization: The experiment utilized Gold (Au) electrodes. 6CCVD offers internal metalization services including Au, Pt, Pd, Ti, W, and Cu deposition, allowing researchers to optimize electrode adhesion and conductivity for high-frequency applications.
- Ultra-Smooth Polishing: Achieving near-surface NV centers requires minimal surface damage. 6CCVD guarantees Ra < 1 nm polishing on Single Crystal Diamond (SCD) wafers, ensuring optimal surface quality for subsequent ion implantation and lithography.
- Custom Dimensions and Cutting: While the paper used 2.0 mm x 2.0 mm blocks, 6CCVD can supply large-area SCD plates and PCD wafers up to 125 mm in diameter, enabling scalable fabrication of quantum devices. We offer precise laser cutting and dicing services to meet exact dimensional requirements.
- Ion Implantation Support: 6CCVD provides substrates optimized for low-energy ion implantation, crucial for creating the near-surface NV centers (approx. 5 nm depth) necessary for strong electric field coupling.
Engineering Support
Section titled âEngineering SupportâThe authors noted that future advancements require integrating electrodes within the diamond bulk to leverage the materialâs high breakdown voltage (21.5 MV/cm) and increase control speed.
6CCVDâs in-house PhD team specializes in material selection and optimization for advanced quantum applications. We offer consultation on:
- Material Selection: Choosing the optimal SCD grade (purity, orientation, and strain level) for specific quantum sensing or quantum computing projects.
- Integration Strategies: Assisting engineers in selecting appropriate thicknesses and surface preparations for micro-machining and electrode integration to maximize electric field strength and control speed.
Call to Action: For custom specifications, material consultation, or to discuss scaling your quantum electrometry project, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
The nitrogen-vacancy (NV) color center quantum system in diamond has shown great application potential in the fields of solid-state quantum computing and quantum precision measurement because of its unique advantages such as single-spin addressing and manipulation and long quantum coherence time at room temperature. The precise manipulation technology of single spin is particularly important for the development of the application of NV center. The common spin manipulation methods used in NV center quantum system are to drive and manipulate the electron spin by resonant alternating magnetic field. In recent years, the electrical control of quantum spin has attracted extensive attention. In this paper, using the alternating electric field to control the electron spin of NV center is studied. The alternating electric field generated by the electrode successfully drives the Rabi oscillation of the NV center spin between the <inline-formula><tex-math id=âM4â>\begin{document}$\Delta m_{\rm{s}}=\pm2$\end{document}</tex-math><alternatives><graphic xmlns:xlink=âhttp://www.w3.org/1999/xlinkâ xlink:href=â11-20220410_M4.jpgâ/><graphic xmlns:xlink=âhttp://www.w3.org/1999/xlinkâ xlink:href=â11-20220410_M4.pngâ/></alternatives></inline-formula> magnetic-dipole forbidden energy levels of <inline-formula><tex-math id=âM5â>\begin{document}$|m_{\rm{s}}=-1\rangle$\end{document}</tex-math><alternatives><graphic xmlns:xlink=âhttp://www.w3.org/1999/xlinkâ xlink:href=â11-20220410_M5.jpgâ/><graphic xmlns:xlink=âhttp://www.w3.org/1999/xlinkâ xlink:href=â11-20220410_M5.pngâ/></alternatives></inline-formula> and <inline-formula><tex-math id=âM6â>\begin{document}$|m_{\rm{s}}=+1\rangle$\end{document}</tex-math><alternatives><graphic xmlns:xlink=âhttp://www.w3.org/1999/xlinkâ xlink:href=â11-20220410_M6.jpgâ/><graphic xmlns:xlink=âhttp://www.w3.org/1999/xlinkâ xlink:href=â11-20220410_M6.pngâ/></alternatives></inline-formula>. Further studies show that the frequency of the electrically driven Rabi oscillation is controlled by the power of the driven electric field but independent of the resonant frequency of the electric field. The combination of spin electric control and magnetic control technology can realize the full manipulation of the direct transition among the three spin energy levels of NV center, thus promoting the development of the researches and applications of NV quantum system in the fields of quantum simulation, quantum computing, precision measurement of electromagnetic field, etc.