All-optical reconfiguration of single silicon-vacancy centers in diamond for non-volatile memories
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2025-07-08 |
| Journal | Nature Communications |
| Authors | Yongzhou Xue, Xiaojuan Ni, Michael Titze, Shei Sia Su, BoâHan Wu |
| Institutions | The University of Texas at Austin, Sandia National Laboratories |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: All-Optical Reconfiguration of Single Silicon-Vacancy Centers in Diamond
Section titled âTechnical Documentation & Analysis: All-Optical Reconfiguration of Single Silicon-Vacancy Centers in DiamondâThis document analyzes the research detailing the all-optical, non-volatile strain engineering of SiV centers in diamond, connecting the experimental requirements and future potential to the advanced MPCVD diamond solutions offered by 6CCVD.
Executive Summary
Section titled âExecutive SummaryâThe research successfully demonstrates a novel, all-optical method for controlling local strain in single Silicon-Vacancy (SiV) centers in diamond, enabling non-volatile optical memory functionality.
- Core Value Proposition: Achieved permanent, non-volatile strain reconfiguration in SiV centers using high-power picosecond pulsed laser irradiation, eliminating the need for continuous external fields or complex nanostructures.
- Mechanism: Pulsed optical irradiation triggers local lattice defect migration (vacancies and self-interstitials), leading to a redistribution of local crystal strain.
- Key Achievement: Demonstrated a Ground State (GS) splitting enhancement from an initial 91 GHz up to 270 GHz after irradiation, with a maximum observed splitting of 1.8 THz.
- Application: The reconfigurable strain states are used to encode non-volatile optical memory, functioning reliably up to 80 K temperature.
- Scalability: The local, permanent nature of the strain control offers a scalable path for enhancing spin coherence in large-scale quantum systems.
- Material Requirement: The method relies on ultra-high purity, electronic-grade diamond substrates, prepared using precise etching, Focused Ion Beam (FIB) implantation, and high-temperature Ultra-High Vacuum (UHV) annealing.
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the research paper, highlighting the critical parameters achieved and utilized in the experiment.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Initial GS Splitting (s1) | 91 | GHz | Strain induced by ion implantation |
| Enhanced GS Splitting (s2) | 270 | GHz | After high-power pulsed laser irradiation |
| Maximum Observed GS Splitting | 1.8 | THz | Experimental maximum achieved |
| DFT Predicted Max GS Splitting | ~39.4 | THz | Theoretical maximum (V3 carbon vacancy) |
| Non-Volatile Operating Temperature | Up to 80 | K | Demonstrated memory functionality |
| SiV PL Lifetime | 1.9 | ns | Characteristic peak C |
| Implantation Ion | 28Si2+ | N/A | Focused Ion Beam (FIB) source |
| Ion Energy | 70 | keV | Implantation parameter |
| Implantation Depth (Simulated) | 48 ± 12 | nm | SRIM simulation result |
| Pulsed Laser Width | 30 | ps | Laser source for strain reconfiguration |
| Pulsed Laser Repetition Rate | 60 | MHz | Laser source for strain reconfiguration |
| Initial Irradiation Pulse Energy | 0.15 | nJ | Energy used to achieve state s2 |
| Diamond Purity (Starting Material) | ~1 | ppb | Electronic-grade diamond (Element 6) |
| Maximum Annealing Temperature | 1200 | °C | UHV post-implantation treatment |
| Diamond Elastic Modulus | ~1050 | GPa | High modulus limits global strain approaches |
Key Methodologies
Section titled âKey MethodologiesâThe successful creation and reconfiguration of the SiV centers required stringent material processing and precise laser control:
- Surface Preparation: Electronic-grade diamond was cleaned (Piranha solution) and etched (10 ”m removal) using oxygen plasma to remove strained surface layers.
- Implantation: Focused Ion Beam (FIB) implantation was performed using 28Si2+ ions at 70 keV, targeting a depth of 48 ± 12 nm, with metal alignment markers used for high precision.
- Post-Implantation Annealing: Samples were annealed in an Ultra-High Vacuum (UHV) environment (1 x 10-8 Torr) with a controlled temperature ramp (100 °C/h) up to a maximum of 1200 °C for 2 hours.
- Chemical Cleaning: Post-annealing, the samples were treated with a tri-acid mixture (H2SO4, HNO3, and HCIO4) boiled at 250 °C, followed by a final Piranha cleaning step.
- Optical Excitation: SiV centers were measured using a home-built confocal microscope (operating at 8 K) excited by CW or pulsed 532 nm green lasers.
- Strain Reconfiguration (Writing): High-power picosecond pulsed laser irradiation (30 ps, 60 MHz) was used to trigger local lattice defect migration, modifying the strain state of the SiV center.
- Verification (Reading): PL spectra and second-order correlation measurements (g(2)(t)) confirmed the single-emitter nature and the resulting non-volatile strain state.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & Capabilitiesâ6CCVD provides the foundational MPCVD diamond materials and advanced processing required to replicate, extend, and scale this critical research in quantum photonics and non-volatile memory.
Applicable Materials
Section titled âApplicable MaterialsâTo achieve the high-coherence and stability demonstrated in this work, the highest quality diamond is essential.
- Optical Grade Single Crystal Diamond (SCD): Required to replicate this research. 6CCVD provides electronic-grade SCD with ultra-low nitrogen and boron content (ppb level), ensuring minimal background defects and maximizing the yield of isolated, high-quality SiV centers created via implantation.
- Custom SCD Substrates: We offer SCD substrates up to 10 mm thick, providing the necessary bulk material for deep etching (10 ”m removal) required to prepare a pristine, strain-free surface prior to ion implantation.
Customization Potential
Section titled âCustomization PotentialâThe paper highlights the need for precise material preparation, including surface removal, implantation, and the potential for future nanostructuring (e.g., cantilevers, photonic crystal cavities) to further enhance performance.
| Research Requirement | 6CCVD Solution & Capability | Technical Advantage |
|---|---|---|
| High-Precision Surface Finish | SCD Polishing: Ra < 1 nm (Atomic Flatness). | Essential for minimizing surface scattering losses and achieving the high-quality interfaces necessary for subsequent lithography and nanostructure fabrication (e.g., membranes, suspended structures). |
| Large-Scale Integration | Custom SCD/PCD Plates/Wafers up to 125 mm (PCD). | Supports the transition from single-emitter studies to large-scale quantum systems and photonic machine learning architectures. |
| Integrated Alignment/Electrodes | Custom Metalization Services (Au, Pt, Pd, Ti, W, Cu). | We offer in-house deposition of thin films for alignment markers (used in FIB) or for fabricating integrated electrodes necessary for combined strain/electric field tuning. |
| Advanced Strain Control | Boron-Doped Diamond (BDD) and customized SCD. | For future co-implantation strategies (as discussed in the paper) or for creating localized strain fields, 6CCVD can supply BDD or SCD tailored for specific defect creation recipes. |
| Custom Dimensions & Thickness | SCD/PCD Thickness range: 0.1 ”m to 500 ”m. | Allows researchers to specify exact membrane or wafer thickness required for specific nanophotonic designs and strain engineering geometries. |
Engineering Support
Section titled âEngineering SupportâThe successful implementation of this all-optical strain control method requires expertise in material science, defect engineering, and high-temperature processing. 6CCVDâs in-house PhD team specializes in MPCVD growth and post-processing techniques, including high-temperature annealing protocols (up to 1200 °C, as used in this paper) and surface preparation.
We offer consultation on material selection, orientation, and processing parameters to optimize the creation of high-coherence SiV centers for similar Quantum Memory and Photonic Machine Learning projects.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Strain engineering is vital for tuning the optical and spin properties of solid-state color centers, enhancing spin coherence and compensating emission wavelength shift. Here, we develop an all-optical approach to directly modify the local strain of color centers at the nanoscale by migrating the nearby defect. High-power pulsed optical irradiation triggers defect migration, which subsequently leads to the redistribution of the local crystal lattice of the host material. This redistribution alters the strain experienced by nearby color centers. Using silicon-vacancy centers in diamond, we validate this method and demonstrate a ground state splitting enhancement of up to 1.8 THz. Unlike conventional methods, our approach requires no external fields or nanostructure modifications, enabling non-volatile strain control and optical memory functionality across wide temperature ranges. Its local, permanent nature offers a scalable path for enhancing spin coherence in large-scale quantum systems and has potential applications in photonic machine learning.