Angle Locking of a Levitating Diamond Using Spin Diamagnetism
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2022-03-18 |
| Journal | Physical Review Letters |
| Authors | M. Perdriat, Paul Huillery, Clément Pellet-Mary, G. Hétet |
| Institutions | Université Paris Sciences et Lettres, Sorbonne Université |
| Citations | 11 |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Spin-Diamagnetism in MPCVD Diamond
Section titled âTechnical Documentation & Analysis: Spin-Diamagnetism in MPCVD DiamondâThis document analyzes the research paper âAngle locking of a Levitating Diamond using Spin-Diamagnetismâ (arXiv:2102.13637v3) to highlight the critical role of high-quality MPCVD diamond materials and to position 6CCVD as the premier supplier for replicating and advancing this quantum spin-mechanics research.
Executive Summary
Section titled âExecutive SummaryâThe research successfully demonstrates a novel method for stabilizing the crystalline axis of levitating micro-diamonds using the strong, tunable diamagnetism induced by Nitrogen-Vacancy (NV) centers.
- Core Achievement: Angle locking of the diamondâs [111] crystalline axis along an external magnetic field (B) by exploiting spin-diamagnetism near the Ground State Level Anti-Crossing (GSLAC).
- Material Transition: The NV-doped diamond transitions from a paramagnetic state (low B-field) to a highly anisotropic diamagnetic state (B > 105 mT) due to population inversion in the electronic ground state.
- Susceptibility Enhancement: The maximum magnetic susceptibility (|Xâ„|) achieved near the GSLAC is approximately 10-2, two orders of magnitude larger than off-resonance values.
- Tunability: The NV axis alignment is optically tunable, steered by green laser-induced polarization to the |ms = 0> state.
- Methodology: Mechanically-Detected-Magnetic-Resonance (MDMR) was employed on micro-diamonds trapped in a ring Paul-Straubel electrostatic trap.
- Application Impact: This technique solves a major challenge in spin-mechanics and quantum sensing by providing robust, microwave-free stabilization of the NV orientation in untethered particles, boosting hyper-polarization efficiency for NMR and advancing matter-wave interferometry.
Technical Specifications
Section titled âTechnical SpecificationsâHard data extracted from the research paper detailing the experimental parameters and material properties.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| NV Center Concentration | 3 - 5 | ppm | Concentration in the micro-diamond sample |
| Zero-Field Splitting (D) | 2.87 | GHz | NV center electronic ground state triplet |
| GSLAC Critical Field (Bc) | 102.4 | mT | Calculated level anti-crossing point |
| Observed Transition Field | â 105 | mT | Magnetic field where the para-to-dia transition occurs |
| Maximum Susceptibility ( | Xâ„ | ) | â 10-2 |
| Longitudinal Spin Relaxation Rate (Î1) | â 2 | kHz | Measured rate due to dipolar interactions |
| Spin Dephasing Rate (Î) | â 5 | MHz | Primarily due to coupling with P1 centers (substitutional nitrogen) |
| Paul Trap Diameter | â 200 | ”m | Ring Paul-Straubel trap dimension |
| Librational Frequencies | 100 Hz - 1 | KHz | Angular confinement range provided by the trap |
| Operating Temperature | Room | Temperature | Experiment conducted at ambient conditions (300 K) |
Key Methodologies
Section titled âKey MethodologiesâThe experiment relies on precise control over the diamond material, trapping environment, and magnetic resonance detection.
- Material Selection: Micro-diamonds containing 3-5 ppm of NV centers were used. The NV centers provide the necessary electronic spin system for induced magnetism.
- Electrostatic Trapping: The micro-diamonds were loaded into a ring Paul-Straubel trap (â 200 ”m diameter) which provided angular confinement, resulting in librational frequencies between 100 Hz and 1 KHz.
- Optical Polarization: A green laser (532 nm) was used to optically pump the NV electronic spin into the highly polarized |ms = 0> state via intersystem crossing in the excited state.
- Magnetic Field Control: An external magnetic field (B) was applied and tuned across the critical GSLAC region (near 105 mT) to induce the transition from paramagnetic to diamagnetic behavior.
- Mechanically-Detected-Magnetic-Resonance (MDMR): A microwave signal was swept to resonantly excite the electronic spins. The resulting change in magnetization generates a torque (Ï) that modifies the diamondâs angular position.
- Angle Read-out: The diamondâs angular motion (librational modes) and the NV axis angle (Ξ) relative to the B-field were tracked using speckle detection of back-reflected light and NV magnetometry (analyzing transition frequencies $v_{0,-1}$ and $v_{0,+1}$).
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThis research demonstrates the critical need for high-quality, customized diamond materials to push the boundaries of quantum spin-mechanics. 6CCVD is uniquely positioned to supply the necessary MPCVD diamond substrates and engineering services to replicate and extend this work.
| Research Requirement/Challenge | 6CCVD Solution & Capability | Technical Advantage |
|---|---|---|
| High-Quality NV Host Material (Controlled N concentration, low strain) | Optical Grade SCD (Single Crystal Diamond) with precise nitrogen incorporation (e.g., 3-5 ppm or higher) during MPCVD growth. | Guaranteed low strain and high crystalline quality, essential for stable NV centers, high polarization efficiency, and long coherence times (T2). |
| Improved Coherence & Purity (Minimizing P1 centers) | Ultra-High Purity SCD with optimized growth recipes to minimize substitutional nitrogen (P1) defects, which limit the spin dephasing rate (Î â 5 MHz in the paper). | Enables significantly longer spin coherence times (T2), critical for high-fidelity quantum sensing and hyper-polarization applications. |
| Custom Dimensions & Geometry (Micro-structures for trapping) | Custom Laser Cutting and Polishing of SCD plates (thickness 0.1 ”m to 500 ”m). We offer plates/wafers up to 125mm (PCD). | Allows researchers to obtain specific micro-structures or wafers with precise [111] orientation for scalable integration into Paul trap systems. |
| Surface Quality for Optical Trapping (Minimizing scattering losses) | Precision Polishing Services: Achieving surface roughness Ra < 1 nm (SCD) and Ra < 5 nm (Inch-size PCD). | Ensures minimal optical loss and stable trapping of levitating particles, crucial for magneto-optical confinement. |
| Integration & Device Fabrication (Future electrical control/MW delivery) | Internal Metalization Services: Deposition of standard contacts (Au, Pt, Pd, Ti, W, Cu) onto diamond substrates. | Provides ready-to-use substrates with integrated antenna structures necessary for efficient microwave delivery and electrical control in MDMR setups. |
| Scaling the Diamagnetic Force (Requires higher NV density) | Heavy Nitrogen Doping Capabilities: We can provide SCD or PCD with NV concentrations optimized for maximizing the internal magnetization (M) and observing the diamagnetic force, potentially leading to superconductor-like levitation. | Direct path to achieving the strong internal magnetization required to observe the diamagnetic force predicted by the authors. |
Engineering Support
Section titled âEngineering Supportâ6CCVDâs in-house PhD team specializes in optimizing MPCVD growth parameters for quantum applications. We can assist researchers in material selection, optimizing doping levels, and achieving the required surface finish for similar NV-based Spin-Mechanics and Quantum Sensing projects.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Nanodiamonds with embedded nitrogen-vacancy (NV) centers have emerged as promising magnetic field sensors, as hyperpolarizing agents in biological environments, as well as efficient tools for spin mechanics with levitating particles. These applications currently suffer from random environmental interactions with the diamond which implies poor control of the N-V direction. Here, we predict and report on a strong diamagnetism of a pure spin origin mediated by a population inversion close to a level crossing in the NV center electronic ground state. We show control of the sign of the magnetic susceptibility as well as angle locking of the crystalline axis of a microdiamond along an external magnetic field, with bright perspectives for these applications.