High-frequency and high-field optically detected magnetic resonance of nitrogen-vacancy centers in diamond
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2015-02-09 |
| Journal | Applied Physics Letters |
| Authors | Viktor Stepanov, Franklin H. Cho, Chathuranga Abeywardana, Susumu Takahashi |
| Institutions | University of Southern California |
| Citations | 52 |
| Analysis | Full AI Review Included |
Technical Analysis of High-Frequency and High-Field NV Center Measurements
Section titled âTechnical Analysis of High-Frequency and High-Field NV Center MeasurementsâExecutive Summary
Section titled âExecutive SummaryâThis paper details the development and application of a novel High-Frequency (HF) Optically Detected Magnetic Resonance (ODMR) system, pushing the limits of quantum sensing and spin control in diamond. The core value proposition and key achievements are summarized below:
- HF/HF Sensing Platform: Successful demonstration of an integrated system capable of performing ODMR measurements of single Nitrogen-Vacancy (NV) centers at extremely high frequencies (up to 240 GHz) and high magnetic fields (up to 12.1 Tesla).
- Single Spin Coherent Control: Demonstrated continuous-wave (cw) and pulsed ODMR, Rabi oscillations, and spin echo measurements of a single NV center at 115 GHz and a resonant field of 4.2 Tesla.
- High Coherence Confirmation: Measured a spin decoherence time (T2) of 325 ± 20 ns for a single NV center in a type-Ib bulk diamond crystal, confirming suitability for quantum information processing.
- Relaxation Dynamics Mapped: Detailed investigation of the longitudinal relaxation time (T1) dependence on magnetic field (0-8 Tesla), showing superior T1 in bulk diamond (1.1 ± 0.5 ms) compared to nanodiamonds (72 ± 14 ”s).
- Robust Operation: The fluorescence (FL) intensity of the NV center remained stable across the entire applied magnetic field range (0-10 Tesla), validating diamondâs stability in extreme electromagnetic environments.
- Foundation for Quantum Engineering: The results showcase the advantages of using high magnetic fields to improve spectral resolution, enhance spin polarization, and distinguish target spins from diamond impurities, critical for scalable NV-based magnetic sensing.
Technical Specifications
Section titled âTechnical SpecificationsâHard data points extracted from the experimental measurements and system design.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| ODMR Frequency (CW/Pulsed) | 115 | GHz | Operating frequency for single NV center measurements |
| Resonant Magnetic Field (B0) | 4.2022 | Tesla | Resonance for the $m_{s}=0 \leftrightarrow -1$ transition |
| System Magnet Strength | 12.1 | Tesla | Superconducting magnet capacity |
| Excitation Wavelength | 532 | nm | CW diode-pumped solid state laser |
| HF Source Range (Low Band) | 107-120 | GHz | Microwave excitation component tunable range |
| HF Source Range (High Band) | 215-240 | GHz | Microwave excitation component tunable range |
| Single NV T2 (Bulk Diamond) | 325 ± 20 | ns | Spin decoherence time measured via spin echo |
| Single NV T1 (Bulk Diamond) | 1.1 ± 0.5 | ms | Longitudinal relaxation time |
| Nanodiamond T1 (35 nm avg) | 72 ± 14 | ”s | Longitudinal relaxation time, 10-100x shorter than bulk |
| Rabi Oscillation Frequency ($f_{Rabi}$) | 0.8 | MHz | Frequency of coherent spin manipulation |
| Pulsed ODMR FWHM | 0.29 (8) | mT (MHz) | Full-width at half-maximum of the ODMR signal |
| Sample Substrate Used | 1.5 Ă 1.5 Ă 1.1 | mmÂł | Single crystal type-Ib diamond (Sumitomo Electric Industries) |
| Initial/Readout Pulse Duration | 4/0.3 | ”s/”s | Initialization (Init.) and Readout (RO) pulse times |
Key Methodologies
Section titled âKey MethodologiesâThe experiment successfully combined high-end microwave engineering, specialized optics, and high-field magnetic environments to measure single spin dynamics.
- Material Selection: Initial measurements were conducted on a bulk single crystal of type-Ib diamond (1.5 x 1.5 x 1.1 mmÂł) and separate NV-enhanced type-Ib nanodiamonds (35 nm average diameter).
- Optical Excitation: A cw 532 nm diode-pumped solid state laser was used for optical excitation, coupled through an Acousto-Optic Modulator (AOM) for precise pulsed operation.
- HF Microwave Delivery: High-frequency microwaves (115 GHz) were guided into the magnetic core via quasioptics and a corrugated waveguide (Thomas-Keating), a component derived from a 12.1 T ESR spectrometer.
- Sample Stage and Microscopy: The diamond sample was placed on a z-translation stage (Attocube) inside the 12.1 Tesla superconducting magnet. A confocal FL imaging system, utilizing a Zeiss objective, was positioned at the magnet center for focused excitation and collection.
- Fluorescence Detection: Collected FL signals were transmitted through a 50 ”m multi-mode optical fiber, filtered by optical filters, and detected by Avalanche Photodiodes (APDs).
- Pulsed Sequences: Rabi oscillations, pulsed ODMR, and spin echo experiments were performed using precise sequences:
- Initialization: 4 ”s laser pulse to prepare the $m_{s}=0$ state.
- Microwave Pulse ($t_{p}$): Applied MW pulse of variable duration to manipulate the spin.
- Readout: 300 ns laser pulse to measure the final FL intensity.
- Data Acquisition: To ensure high signal-to-noise ratio in single-spin measurements, each data point was obtained by averaging the results of repeating the pulse sequence on the order of 106 times.
6CCVD Solutions & Capabilities: Enabling Advanced Quantum Spintronics
Section titled â6CCVD Solutions & Capabilities: Enabling Advanced Quantum SpintronicsâThe research confirms that high-purity diamond is the essential host material for extreme-condition quantum sensing. 6CCVD specializes in providing the precise Single Crystal Diamond (SCD) and Polycrystalline Diamond (PCD) substrates required to replicate and advance this high-frequency, high-field research.
| Paper Requirement/Application | 6CCVD Recommended Material | Critical Capability & Advantage |
|---|---|---|
| High Spin Coherence (Long T2) | Quantum Grade SCD (Low Nitrogen): Required for applications requiring maximum T2. Low substitutional nitrogen content (< 1 ppb) minimizes paramagnetic noise and prolongs coherence times, crucial for fidelity in Rabi and spin echo experiments. | 6CCVD offers SCD with exceptionally low defect density, significantly improving upon the type-Ib precursor material used in the paper, leading to predicted T2 gains. |
| High T1 Reliability | Optical Grade SCD (Custom Doping): By carefully controlling the [N] concentration and NV creation process (either in situ growth or post-growth irradiation), we can engineer T1 lifetime for specific magnetic sensing or thermal equilibrium needs. | MPCVD thickness control from 0.1 ”m to 500 ”m allows for ultra-thin films optimized for surface sensing or robust bulk substrates (up to 10mm thickness). |
| Extreme Physical Integration | Custom Dimensions & Polishing: The system requires diamond wafers cut precisely for mounting within a cryogenic, high-field magnet and aligned with complex optics/waveguides. | Custom Dimensions: Plates/wafers up to 125mm. Precision Cutting: Laser cutting and dicing services ensure fitment to the tight tolerances of high-end spectroscopic equipment. |
| On-Chip Device Integration | Advanced Metalized Substrates: For next-generation ODMR systems that integrate microwave control directly onto the chip, researchers need metalized surfaces for transmission lines. | In-House Metalization: We apply custom thin-film metal stacks (e.g., Ti/Pt/Au, Ti/W/Cu) required for microwave transmission (up to 115 GHz and beyond) and thermal management in extreme environments. |
| Nanodiamond Research Extension | High-Density Polycrystalline Diamond (PCD): While the paper used external nanodiamonds, 6CCVD can supply high-quality PCD or large-area SCD precursors for subsequent processing (e.g., etching or milling) into high-purity nanostructures. | Our PCD offers large-area coverage (up to 125mm) with controlled grain size, facilitating high-throughput sample preparation. |
Engineering Support & Consultation
Section titled âEngineering Support & Consultationâ6CCVDâs in-house team of PhD material scientists and technical engineers are experts in tuning MPCVD growth parameters to meet the stringent demands of quantum research. We provide critical assistance in:
- Material Selection: Determining the optimal balance between high purity (low-N SCD for long T2) and high NV yield (BDD or specially treated SCD) for specific high-field ODMR and quantum computing projects.
- Interface Optimization: Ensuring custom polishing (Ra < 1 nm for SCD) provides the ideal optical interface needed for efficient 532 nm excitation and fluorescence collection in confocal setups, especially those integrated into magnets.
- Physical Integration: Advising on material dimensions, crystal orientation (e.g., NV alignment along the [111] axis mentioned in the paper), and metalization schemes for reliable device prototyping.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
We present the development of an optically detected magnetic resonance (ODMR) system, which enables us to perform the ODMR measurements of a single defect in solids at high frequencies and high magnetic fields. Using the high-frequency and high-field ODMR system, we demonstrate 115 GHz continuous-wave and pulsed ODMR measurements of a single nitrogen-vacancy (NV) center in a diamond crystal at the magnetic field of 4.2 T as well as investigation of field dependence (0-8 T) of the longitudinal relaxation time (T1) of NV centers in nanodiamonds.