Magnetic resonance and quantum sensing with color centers under high pressures
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2025-01-01 |
| Journal | Acta Physica Sinica |
| Authors | GangâQin Liu |
| Citations | 1 |
| Analysis | Full AI Review Included |
Executive Summary
Section titled âExecutive SummaryâThis research details the successful integration of Diamond Nitrogen-Vacancy (NV) center quantum sensing with Diamond Anvil Cell (DAC) technology, enabling unprecedented magnetic resonance and sensing capabilities under extreme high-pressure conditions.
- Extreme Environment Sensing: NV centers function reliably as quantum sensors up to 140 GPa (megabar pressures) and high temperatures (up to 1400 K), overcoming the limitations of traditional magnetic resonance (MR) techniques that require large sample volumes.
- High Sensitivity and Resolution: The technique achieves magnetic sensitivity down to 1 ”T/âHz under high pressure, with a spatial resolution approaching 1 ”m, allowing for micro-scale, in-situ measurements.
- In-Situ Pressure Metrology: The pressure dependence of the NV center Zero-Field Splitting (ZFS) is calibrated, providing a high-spatial-resolution, in-situ pressure gauge (e.g., 7.24 to 13.41 MHz/GPa shift rate).
- Magnetic Phase Mapping: Demonstrated micro-scale magnetic imaging of materials (e.g., Fe3O4) under pressure, successfully mapping magnetic domain walls and phase transitions up to 130 GPa.
- Superconductivity Verification: Enabled the direct, local measurement of the Meissner effect (diamagnetism) in micro-scale high-pressure superconductors (e.g., CeH9 and La2PrNi2O7), providing crucial evidence beyond zero-resistance tests.
- Nuclear Spin Control: Explored dynamic nuclear spin polarization (DNP) and 14N Nuclear Magnetic Resonance (NMR) under pressure, revealing how pressure affects electron-nuclear hyperfine coupling.
Technical Specifications
Section titled âTechnical Specificationsâ| Parameter | Value | Unit | Context |
|---|---|---|---|
| Maximum Working Pressure | 140 | GPa | Demonstrated operational pressure for NV sensing. |
| Magnetic Sensitivity (High P) | 1 | ”T/âHz | Achieved magnetic sensitivity under high pressure. |
| Spatial Resolution | Near 1 | ”m | Achieved for magnetic imaging within the DAC. |
| NV ZFS (Zero Pressure, D0) | 2.88 ± 0.03 | GHz | Baseline frequency for NV ground state. |
| NV ZFS Pressure Shift (111 cut) | 7.24 ± 0.14 | MHz/GPa | Pressure calibration slope for (111) cut diamond. |
| NV ZFS Pressure Shift (001 cut, improved) | 13.41 ± 0.14 | MHz/GPa | Pressure calibration slope for (001) cut with improved hydrostatic environment. |
| 14N NMR Quadrupole Shift (dQ/dP) | 3.5 ± 0.4 | kHz/GPa | Rate of change of nuclear quadrupole term with pressure. |
| 14N NMR Hyperfine Shift (dA///dP) | 4.9 ± 1.1 | kHz/GPa | Rate of change of hyperfine coupling with pressure. |
| 14N Nuclear Spin Dephasing Time (TN*) | 70 ± 10 | ”s | Measured in microdiamond under pressure. |
| Electron Spin Relaxation Time (T1e) | 354 ± 31 | ”s | Measured under pressure (limits nuclear coherence). |
| SiC VSi ZFS Pressure Shift | 0.31 ± 0.1 | MHz/GPa | Pressure calibration slope for Silicon Vacancy in 4H-SiC. |
| hBN VB ZFS Pressure Shift | 43 ± 0.3 | MHz/GPa | Pressure calibration slope for Boron Vacancy in hBN. |
| Fe3O4 Magnetic Transition (αâÎČ) | Near 30 | GPa | Observed transition pressure for magnetite. |
| Fe3O4 Magnetic Transition (ÎČâÎł) | Near 70 | GPa | Observed transition pressure for magnetite. |
Key Methodologies
Section titled âKey Methodologiesâ- High-Pressure Generation: Diamond Anvil Cell (DAC) utilized, often featuring specialized (111) or (001) cut diamond anvils to optimize NV center orientation and optical access.
- NV Center Integration: NV centers are introduced into the DAC chamber via two primary methods:
- Particle Loading: Micro- or nano-diamond particles containing NV centers are placed within the pressure-transmitting medium (PTM) alongside the sample.
- Anvil Fabrication: Shallow NV layers are created directly on the diamond anvil culet surface using ion implantation (e.g., N+) followed by high-temperature annealing (>600 °C).
- Hydrostatic Control: Pressure-transmitting media (PTMs) such as KBr, Ne, He, or silicon oil are used. Improved hydrostatic conditions are achieved by etching micro-trenches (e.g., 2 ”m deep) into the anvil culet to better contain the PTM and reduce strain broadening.
- Spin Control and Readout:
- Excitation: 532 nm laser is used for optical pumping and excitation through the transparent diamond anvils.
- Microwave (MW) Delivery: MW antennas (Pt or Au films) are fabricated onto the anvil surface or placed near the sample to deliver MW pulses for spin manipulation.
- Detection: Optically Detected Magnetic Resonance (ODMR) spectroscopy is performed by monitoring the photoluminescence (PL) intensity change as a function of MW frequency.
- Dynamic Nuclear Polarization (DNP): High nuclear spin polarization of 14N is achieved by aligning the external magnetic field (around 500 G) to the Excited State Level Anti-Crossing (ESLAC) point of the NV center, enabling subsequent NMR measurements.
- Meissner Effect Measurement: The local magnetic field (Bmag) near the superconducting sample is measured using NV centers during Zero-Field Cooling (ZFC) and Field Cooling (FC) sequences to quantify the diamagnetic screening (s < 1).
Commercial Applications
Section titled âCommercial Applicationsâ- Quantum Metrology in Extreme Environments:
- Manufacturing and calibration of robust, micro-scale pressure and magnetic sensors capable of operating in high-pressure, high-temperature (HPHT) industrial processes or geological simulations.
- Advanced Materials Discovery:
- In-situ characterization of novel electronic materials, including high-Tc superconductors (e.g., hydrogen-rich compounds) and magnetic materials, under synthesis or operating conditions (up to 140 GPa).
- Geophysics and Planetary Science:
- Laboratory simulation of Earth and planetary core conditions, enabling the study of magnetic properties and phase transitions of minerals (e.g., Fe3O4) under megabar pressures and high temperatures.
- Quantum Device Engineering:
- Precise mapping and control of strain and pressure gradients in solid-state quantum devices (diamond, SiC, hBN) to optimize the coherence time (T2) and spectral stability of color centers.
- Non-Destructive Testing (NDT) at Microscale:
- Micro-scale stress and magnetic field mapping of components under extreme mechanical load, relevant for aerospace and high-reliability engineering.
View Original Abstract
High-pressure extreme conditions are crucial for realizing novel states and regulating material properties, while magnetic resonance technology is a widely used method to characterize microscopic magnetic structures and magnetic properties. The integration of these two fields offers new opportunities for cutting-edge research in condensed matter physics and materials science. However, conventional magnetic resonance is limited by several factors, such as low spin polarization and low signal detection efficiency, which makes in-situ measurement of micrometer-sized samples under ultra-high pressure a challenge. Recent advances in quantum sensing with color centers in solids, in particular, the development of quantum sensors based on nitrogen vacancy (NV) centers in diamond, provide an innovative solution for magnetic resonance and in-situ quantum sensing under high pressure. This article summarizes the effects of high-pressure conditions on the spin and optical properties, as well as on the magnetic resonance of diamond NV centers. In addition, this article reviews recent advances in high-pressure quantum sensing through applications such as magnetic imaging, pressure detection, and the study of the superconducting Meissner effect under high pressure.