Quantum magnetometry of transient signals with a time resolution of 1.1 nanoseconds
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2025-01-18 |
| Journal | Nature Communications |
| Authors | Konstantin Herb, Laura A. VÓ§lker, John M. Abendroth, Nicholas Meinhardt, Laura van Schie |
| Institutions | ETH Zurich |
| Citations | 5 |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Ultra-Fast Quantum Magnetometry
Section titled âTechnical Documentation & Analysis: Ultra-Fast Quantum MagnetometryâReference: K. Herb et al., âQuantum magnetometry of transient signals with a time resolution of 1.1 nanoseconds,â Nature Communications 16:822 (2025).
Executive Summary
Section titled âExecutive SummaryâThis research demonstrates a significant advancement in quantum sensing, achieving nanosecond-scale time resolution for magnetic field detection using a single Nitrogen-Vacancy (NV) center in diamond. This capability is critical for rapidly evolving fields such as spintronics and nanoscale device metrology.
- Record Temporal Resolution: Achieved a best-effort time resolution of 1.1 ns and an instantaneous bandwidth of 0.9 GHz, an order of magnitude faster than previous targeted approaches.
- Core Application: Enables time-resolved investigation of ultra-fast magnetic phenomena, including magnetization reversals and domain wall propagation in magnetic nanostructures.
- Material Foundation: Success relies on high-quality, electronic-grade Single Crystal Diamond (SCD) substrates integrated with nanopillar waveguide arrays and optimized Co-Planar Waveguide (CPW) antennas.
- High-Frequency Performance: Demonstrated high Rabi frequencies (Ω/2Ï â 125 MHz, corresponding to Bmw â 6.3 mT) essential for short-pulse quantum control sequences.
- Precision Timing: Achieved a Time-of-Flight (ToF) precision better than 20 ps, demonstrating exceptional timing stability for transient signal analysis.
- Future Scalability: The methodology is scalable toward picosecond resolution, requiring advanced diamond integration and ultra-low loss microwave delivery systems.
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the experimental results and methodology sections:
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Best-Effort Time Resolution (tmin) | 1.1 | ns | Achieved using α = 45° spin rotation angle |
| Instantaneous Frequency Bandwidth (ΩBw) | 0.9 | GHz | Corresponding to 1.1 ns resolution |
| Time-of-Flight (ToF) Precision | < 20 | ps | Absolute timing error |
| Maximum Rabi Frequency (Ω/2Ï) | 125 | MHz | Achieved with Bmw â 6.3 mT |
| Nominal Sensitivity (Bmin) | 35 | ”T/Hz | Calculated for α = Ï/2, Ï = 2 ns |
| Bias Magnetic Field (B0) | 36 | mT | Applied axially to isolate ms=0 to ms=-1 transition |
| NV Center Implantation Energy | 5 | keV | 15N+ ion implantation |
| NV Center Implantation Fluence | 109 | cm-2 | Used for single NV creation |
| Annealing Temperature | 1200 | °C | Required for NV activation |
| CPW 3 dB Bandwidth | ca. 7.5 | GHz | Coplanar Waveguide antenna design |
| CPW Center Conductor Width | 20 | ”m | Narrowed core section for field concentration |
Key Methodologies
Section titled âKey MethodologiesâThe experimental success hinges on precise material engineering and advanced quantum control techniques:
- Substrate Selection and Preparation: Experiments utilized electronic-grade Single Crystal Diamond (SCD) with natural isotope composition, ensuring high material purity necessary for long NV coherence times.
- NV Center Creation: NV centers were created via 15N+ ion implantation (5 keV energy, 109 cm-2 fluence), followed by high-vacuum annealing at 1200 °C for 4 hours to activate the defects.
- Photonic Structure Fabrication: Nanopillar waveguide arrays were fabricated on membrane samples using electron-beam lithography (EBL) and Reactive Ion Etching (RIE) to enhance photon collection efficiency.
- Microwave Delivery Integration: A broad-band (ca. 8 GHz) Co-Planar Waveguide (CPW) antenna, fabricated by patterning gold onto a quartz coverslip, was positioned within ca. 25 ”m of the NV center array to maximize the microwave field amplitude (Bmw).
- Quantum Control Protocol: A pump-probe scheme employing equivalent-time sampling and a speed-optimized two-pulse sequence (P1-P2) was used to sample the transient magnetic field B(t).
- Signal Deconvolution: Time resolution was optimized post-measurement using numerical Wiener deconvolution, which accounts for pulse distortions and the full S=1 nature of the NV spin system (including non-linear effects and Bloch-Siegert shifts).
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThe demonstrated research requires ultra-high quality diamond substrates and advanced fabrication capabilitiesâcore competencies of 6CCVD. We provide the necessary materials and engineering support to replicate, extend, and industrialize this cutting-edge quantum magnetometry technique.
Applicable Materials
Section titled âApplicable MaterialsâTo achieve the long coherence times and low noise floor required for this nanosecond sensing protocol, the research necessitates the highest quality diamond.
- Optical Grade Single Crystal Diamond (SCD): 6CCVD offers electronic-grade SCD plates with extremely low nitrogen and defect concentrations, crucial for maximizing the NV center coherence time (T2) and minimizing baseline noise (Bmin â 35 ”T/Hz).
- Custom Thicknesses: We supply SCD wafers ranging from 0.1 ”m up to 500 ”m, allowing researchers to optimize the thickness for subsequent nanopillar fabrication and membrane processing (RIE etching).
Customization Potential
Section titled âCustomization PotentialâThe integration of NV centers with complex microwave structures (CPW) and photonic elements (nanopillars) demands precise material processing and integration services, which 6CCVD provides in-house.
| Research Requirement | 6CCVD Capability | Technical Advantage |
|---|---|---|
| Substrate Geometry | Custom dimensions for plates/wafers up to 125 mm (PCD) and custom SCD sizes. | Supports precise integration into high-frequency microwave setups and custom chip carriers. |
| Surface Quality | Ultra-low roughness polishing: Ra < 1 nm (SCD). | Essential for high-fidelity electron-beam lithography (EBL) and subsequent RIE etching required for nanopillar waveguide arrays. |
| Microwave Integration | Internal metalization services: Au, Ti, Pt, Pd, W, Cu. | Enables direct fabrication of high-performance CPW antennas (e.g., Ti/Au stacks) onto the diamond surface, ensuring precise impedance matching and minimizing absorptive losses necessary for high Rabi frequencies (>125 MHz). |
| Advanced Structures | Laser cutting and shaping services. | Facilitates the creation of complex geometries and precise alignment features required for optical and microwave coupling. |
Engineering Support
Section titled âEngineering SupportâThe transition to picosecond resolution requires achieving Rabi frequencies exceeding 1 GHz, demanding specialized material selection and integration strategies to manage high-frequency effects (e.g., Bloch-Siegert shifts, non-resonant transitions).
- Application Expertise: 6CCVDâs in-house PhD team specializes in material selection and optimization for similar Spintronics, Nanoscale Device Metrology, and Quantum Sensing projects.
- High-Frequency Optimization: We consult on material specifications (e.g., low-loss dielectric properties) necessary for achieving the ultra-high Rabi frequencies (440 MHz to >1 GHz) required for next-generation picosecond sensing protocols.
- Global Logistics: We offer reliable global shipping (DDU default, DDP available) to ensure rapid delivery of custom-engineered diamond solutions worldwide.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.