Diamond-based quantum technologies
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2021-03-01 |
| Journal | Photoniques |
| Authors | Toeno van der Sar, T. H. Taminiau, Ronald Hanson |
| Institutions | QuTech, Delft University of Technology |
| Citations | 2 |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Diamond-Based Quantum Technologies
Section titled âTechnical Documentation & Analysis: Diamond-Based Quantum TechnologiesâSource Paper: VAN DER SAR, T., TAMINIAU, T. H., & HANSON, R. (2021). Diamond-Based Quantum Technologies. Photoniques 107.
Executive Summary
Section titled âExecutive SummaryâThis research highlights the critical role of optically accessible spin defects (NV, SiV, SnV centers) in MPCVD diamond as a leading platform for next-generation quantum technologies. 6CCVD is positioned to supply the high-purity, precision-engineered diamond required for industrialization and scaling.
- Core Application: Diamond defect spins serve as versatile solid-state qubits for quantum sensing, computation, simulation, and long-range quantum networks.
- Key Material Requirement: Ultra-pure, low-strain Single Crystal Diamond (SCD) is essential to achieve the demonstrated long quantum coherence times (exceeding minutes) and room-temperature operation.
- Sensing Capabilities: NV centers enable high-resolution magnetometry and imaging of magnetic fields and electrical currents, operating from cryogenic temperatures up to 300 K.
- Scalability Challenge: Scaling up quantum processors and networks requires improved materials, advanced fabrication (nanostructures, photonic circuits), and high-fidelity optical interfaces.
- 6CCVD Value Proposition: We provide custom-grown, high-purity SCD substrates and precision polishing (Ra < 1nm) necessary for the nanofabrication of solid-immersion lenses, nanobeams, and integrated photonic circuits (e.g., Fig. 4c).
- Entanglement Generation: The platform supports the creation of long-range entanglement links between distant nodes via photons, a fundamental requirement for quantum internet realization.
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points extracted from the research define the performance metrics and physical requirements of diamond-based quantum systems:
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Qubit Coherence Time | > Minutes | Time | Demonstrated in 10-qubit processors. Requires ultra-pure SCD. |
| Operating Temperature Range | Cryogenic to Room Temperature | ° | Versatility for sensing and computation applications. |
| Spatial Resolution (Sensing) | ~50 | nm | Achieved using NV spin in diamond nanotip scanning (AFM integration). |
| Magnetic Field Detection (DC) | 503.9 | G | Example of DC magnetic field measured via ESR frequency shift. |
| Magnetic Coupling Distance | 10-50 | nm | Short-range coupling distance between adjacent defect centers. |
| Diamond Substrate Thickness | 500 | ”m | Example thickness for bulk diamond plates used in sensing experiments (Fig. 1e). |
| Integrated Photonic Circuit Feature Size | 3 | ”m | Width of integrated waveguides in quantum microchiplets (Fig. 4c). |
| Defect Types Studied | NV, SiV, SnV | N/A | Optically active atomic defects used as qubits/sensors. |
Key Methodologies
Section titled âKey MethodologiesâThe successful implementation of diamond-based quantum technologies relies on precise material engineering and advanced nanofabrication techniques, all supported by 6CCVDâs material capabilities.
- High-Purity MPCVD Growth: Growth of high-quality Single Crystal Diamond (SCD) is the foundational step, ensuring low intrinsic defect density and minimal strain necessary for long quantum coherence times.
- Defect Engineering (Implantation/Doping): Creation of specific, optically active defects (NV, SiV, SnV) either through controlled nitrogen/silicon doping during growth or through shallow ion implantation post-growth.
- Optical Initialization and Readout: Utilizing spin-dependent photoluminescence (PL) via laser excitation to initialize and measure the electron spin state of the defect centers.
- Nanofabrication for Interface Optimization: Fabrication of microstructures such as solid-immersion lenses (SILs), nanobeams, and diamond nanotips to enhance photon collection efficiency and achieve nanometer proximity to samples.
- Spin Control via Microwave/RF Fields: Application of GHz fields to drive electron spin resonance (ESR) transitions, enabling precise control and measurement of the spin state (e.g., magnetometry).
- Integrated Photonics: Fabrication of diamond âquantum microchipletsâ featuring optical waveguides and integrated electronic controls to scale up modular quantum processors and networks.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & Capabilitiesâ6CCVD provides the specialized MPCVD diamond materials and precision engineering services required to replicate, scale, and advance the quantum research detailed in this paper.
Applicable Materials
Section titled âApplicable MaterialsâTo achieve the long coherence times and high optical fidelity required for NV/SiV/SnV centers, researchers need the highest quality material.
| 6CCVD Material | Recommended Specification | Application Alignment |
|---|---|---|
| Optical Grade SCD | Ultra-low Nitrogen (ULN) < 1 ppb, Low Birefringence | Essential for long coherence times and high-fidelity optical initialization/readout of NV/SiV/SnV centers. |
| High-Purity SCD Substrates | Thickness up to 10 mm, Custom Dimensions up to 125 mm | Required for bulk sensing applications (500 ”m plates) and as robust platforms for subsequent nanofabrication. |
| Precision Polished SCD | Surface Roughness Ra < 1 nm | Critical for minimizing scattering losses and maximizing coupling efficiency in solid-immersion lenses and integrated photonic structures. |
| Boron-Doped Diamond (BDD) | Heavy Doping (Conductive) | While not the primary qubit material, BDD can be supplied for integrated electrodes or microwave transmission lines necessary for spin control (GHz fields). |
Customization Potential
Section titled âCustomization PotentialâThe research explicitly requires materials compatible with advanced micro- and nanofabrication (nanobeams, photonic circuits, metal contacts). 6CCVD offers comprehensive customization to meet these engineering demands:
- Custom Dimensions and Thickness: We supply plates and wafers up to 125 mm (PCD) and SCD substrates up to 10 mm thick, accommodating the 500 ”m plates and the thin films (0.1 ”m - 500 ”m) needed for shallow implantation and nanostructure fabrication.
- Ultra-Precision Polishing: Our internal capability ensures SCD surfaces achieve Ra < 1 nm, which is vital for high-quality optical interfaces and low-loss waveguide integration (Fig. 4c).
- Custom Metalization Services: For integrated electronic controls, microwave delivery, and contact pads, 6CCVD offers in-house deposition of standard quantum stack materials, including Au, Pt, Pd, Ti, W, and Cu.
- Laser Cutting and Shaping: We provide precision laser cutting services to create custom shapes, such as the diamond chiplets and nanobeam precursors, facilitating integration into complex experimental setups.
Engineering Support
Section titled âEngineering Supportâ6CCVDâs in-house PhD team specializes in MPCVD growth optimization and defect engineering for quantum applications. We offer authoritative support for researchers and engineers:
- Material Selection for Defect Creation: Assistance in selecting the optimal SCD purity and orientation for efficient creation and stable operation of specific defect centers (NV, SiV, SnV).
- Interface Optimization: Consultation on surface preparation and polishing protocols to ensure maximum compatibility with subsequent nanofabrication steps (e.g., etching for nanobeams or deposition for solid-immersion lenses).
- Scalability Planning: Support for projects transitioning from proof-of-principle demonstrations to modular, large-scale quantum processors and quantum network nodes.
Call to Action: For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Optically accessible spins associated with defects in diamond provide a versatile platform for quantum science and technology. These spins combine multiple key characteristics, including long quantum coherence times, operation up to room temperature, and the capability to create long-range entanglement links through photons. These unique properties have propelled spins in diamond to the forefront of quantum sensing, quantum computation and simulation, and quantum networks.