Ultrafast opto-magnetic effects induced by nitrogen-vacancy centers in diamond crystals

At a Glance

Metadata	Details
Publication Date	2022-06-01
Journal	APL Photonics
Authors	Ryosuke Sakurai, Yuta Kainuma, Toshu An, Hidemi Shigekawa, Muneaki Hase
Institutions	University of Tsukuba, Japan Advanced Institute of Science and Technology
Citations	6
Analysis	Full AI Review Included

Technical Documentation & Analysis: Ultrafast Opto-Magnetic Effects in NV Diamond

This document analyzes the research paper “Ultrafast opto-magnetic effects induced by nitrogen-vacancy centers in diamond crystals” to provide technical specifications and align the material requirements with 6CCVD’s specialized MPCVD diamond catalog, driving sales to researchers in quantum sensing and nonlinear optics.

Executive Summary

This research demonstrates a significant advancement in quantum sensing by achieving sub-picosecond time resolution using Nitrogen-Vacancy (NV) centers in CVD diamond crystals.

Breakthrough Sensing Speed: Achieved sub-picosecond time resolution for magnetic sensing, overcoming the microsecond limitations of conventional NV luminescence lifetime techniques.
Mechanism: Observation of the Inverse Cotton-Mouton Effect (ICME) and Inverse Faraday Effect (IFE) via femtosecond pump-probe Kerr rotation measurements.
Material Requirement: High-purity, low-impurity [100] Single Crystal Diamond (SCD) is required as the substrate for subsequent nitrogen implantation and annealing.
Opto-Magnetic Effect: The ICME signal exhibits a quadratic dependence on pump fluence, confirming its origin as a second-order opto-magnetic effect driven by NV electron spin ensembles.
Performance Metric: Estimated detectable magnetic field strength of approximately 35 mT (3.5×10² Oe) using this ultrafast technique.
Future Integration: The methodology is positioned for integration with Scanning Probe Microscopy (SPM) techniques to enable high spatial-temporal resolution quantum sensing in advanced materials and devices.

Technical Specifications

Parameter	Value	Unit	Context
Time Resolution Achieved	Sub-picosecond	Time	Ultrafast opto-magnetic sensing
Detectable Magnetic Field (	M	)	3.5×10²
Starting Material	[100] Type-IIa SCD	Crystal	CVD grown, low impurity
Sample Dimensions	3.0 × 3.0 × 0.3	mm	Thickness is 300 µm
Nitrogen Impurity ([N])	< 1	ppm	Required for Type-IIa purity
Boron Impurity ([B])	< 0.05	ppm	Required for Type-IIa purity
Nitrogen Ion Implantation Energy	30	keV	Used to create NV centers
Implantation Depth	30-40	nm	Deduced from Monte Carlo calculation
NV Concentration (Sample C)	1.0×10¹²	ions/cm²	Highest concentration tested
Pump Laser Wavelength	≈800	nm	Femtosecond regenerative amplifier
Pump Pulse Duration	≈40	fs	Used for ultrafast excitation
Pump Fluence (I) Range	8.0 to 40.0	mJ/cm²	Range tested for fluence dependence
Annealing Temperature	900-1000	°C	Used for NV center formation

Key Methodologies

The research relied on precise material engineering and advanced femtosecond spectroscopy to realize the ultrafast opto-magnetic effects.

Substrate Selection: High-purity, low-impurity Element Six [100] type-IIa Single Crystal Diamond (SCD) was chosen to minimize background defects and maximize NV center quality.
Nitrogen Implantation: ¹⁴N⁺ ions were implanted at 30 keV to introduce nitrogen defects near the surface. Two doses were used: 2.0×10¹¹ ions/cm² (Sample B) and 1.0×10¹² ions/cm² (Sample C).
Annealing: Samples were annealed at 900°C-1000°C in an argon atmosphere for 1 hour to mobilize vacancies, allowing them to pair with implanted nitrogen atoms to form the negatively charged NV^- centers.
Optical Measurement Setup: A reflection-based pump-probe Kerr-rotation technique was employed, utilizing a femtosecond regenerative amplifier system (≈40 fs pulses, ≈800 nm, 100 kHz repetition rate).
Polarization Control: A quarter-wave plate (QWP) was varied to control the pump beam polarization (helicity) from linear (0°, 90°, 180°) to right- and left-handed circular (45°, 135°).
Signal Analysis: The change in Kerr rotation ($\Delta\theta_k$) was measured as a function of pump-probe delay and fitted using a combination of $\sin 2\alpha$ (IFE), $\sin 4\alpha$ (OKE), and the newly observed $\sin 6\alpha$ (ICME) components to separate the distinct opto-magnetic effects.

6CCVD Solutions & Capabilities

6CCVD is uniquely positioned to supply the foundational materials and custom engineering required to replicate and extend this ultrafast quantum sensing research.

Applicable Materials

To replicate the high-performance NV diamond used in this study, researchers require the highest quality, low-defect starting material.

Optical Grade Single Crystal Diamond (SCD): This is the ideal substrate. 6CCVD provides high-purity, low-strain SCD wafers with nitrogen concentrations significantly below 1 ppm, ensuring minimal background noise and optimal NV center formation efficiency post-implantation.
Custom Thickness SCD: The paper used 300 µm thick samples. 6CCVD offers SCD plates ranging from 0.1 µm up to 500 µm, allowing researchers to optimize thickness for specific optical transmission or reflection geometries.
[100] Orientation: 6CCVD supplies SCD with precise crystallographic orientation, matching the [100] orientation critical for the NV center alignment and subsequent opto-magnetic measurements described.

Customization Potential

The integration of ultrafast sensing with SPM requires precise dimensions and potentially integrated electrical components.

Requirement from Paper/Application	6CCVD Custom Capability	Benefit to Researcher
Dimensions (3.0 mm × 3.0 mm)	Custom laser cutting and dicing	Precise dimensions for integration into SPM heads or device packaging.
Surface Quality (Pump-Probe Reflection)	Ultra-low roughness polishing (Ra < 1 nm)	Essential for minimizing scattering losses and maximizing signal-to-noise ratio in reflection-based pump-probe setups.
Future Device Integration	Custom Metalization (Au, Pt, Ti, Pd, W, Cu)	Enables integration of on-chip microwave antennas or electrical contacts necessary for advanced ODMR or device-operating condition studies.
Large Area Substrates	PCD wafers up to 125 mm diameter	Allows for scaling up research or fabricating large arrays of sensing elements.

Engineering Support

The successful creation of high-density NV ensembles relies heavily on the quality of the starting diamond substrate and precise post-processing.

Material Consultation: 6CCVD’s in-house PhD team specializes in MPCVD growth parameters and can assist researchers in selecting the optimal SCD grade (purity, orientation, and thickness) necessary for high-efficiency nitrogen implantation and annealing protocols for Ultrafast Quantum Sensing projects.
Purity Control: We provide detailed specifications on residual impurity levels (N and B) to ensure the substrate meets the stringent requirements for creating the negatively charged NV^- state (which dominates the electronic state in this research).
Global Logistics: 6CCVD offers reliable global shipping (DDU default, DDP available) to ensure prompt delivery of critical materials worldwide.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

The current generation of quantum sensing technologies using color centers in diamond crystals is primarily based on the principle that the resonant microwave frequency of the luminescence between quantum levels of the nitrogen-vacancy (NV) center varies with temperature and electric and magnetic fields. This principle enables us to measure, for instance, magnetic and electric fields, as well as local temperature with nanometer resolution in conjunction with a scanning probe microscope (SPM). However, the time resolution of conventional quantum sensing technologies has been limited to microseconds due to the limited luminescence lifetime. Here, we investigate ultrafast opto-magnetic effects in diamond crystals containing NV centers to improve the time resolution of quantum sensing to sub-picosecond time scales. The spin ensemble from diamond NV centers induces an inverse Cotton-Mouton effect (ICME) in the form of a sub-picosecond optical response in a femtosecond pump-probe measurement. The helicity and quadratic power dependence of the ICME can be interpreted as a second-order opto-magnetic effect in which ensembles of NV electron spins act as a source for the ICME. The results provide fundamental guidelines for enabling high-resolution spatial-time quantum sensing technologies when combined with SPM techniques.

Tech Support

Original Source

DOI: https://doi.org/10.1063/5.0081507