Nuclear Spin Gyroscope based on the Nitrogen Vacancy Center in Diamond

At a Glance

Metadata	Details
Publication Date	2021-05-14
Journal	Physical Review Letters
Authors	Vladimir V. Soshenko, Stepan V. Bolshedvorskii, Olga R. Rubinas, Vadim N. Sorokin, Andrey N. Smolyaninov
Institutions	Texas A&M University, Center for Integrated Quantum Science and Technology
Citations	83
Analysis	Full AI Review Included

Technical Documentation & Analysis: NV Center Nuclear Spin Gyroscope

Executive Summary

This research demonstrates a critical step toward realizing compact, high-precision, solid-state inertial navigation systems using Nitrogen-Vacancy (NV) centers in diamond. The key findings and value proposition for 6CCVD clients are summarized below:

Solid-State Gyroscope Proof-of-Concept: Successful demonstration of the first proof-of-principle direct gyroscopic measurement of sub-Hz rotation using an ensemble of hyperpolarized $^{14}$N nuclear spins in diamond.
Drift-Free Potential: The use of fundamental particle spins offers a drift-free alternative to traditional mechanoelectronic (MEMS) gyroscopes, addressing the long-term stability gap between MEMS and high-end fiber-optic gyros.
Advanced Spin Control: The methodology relies on complex quantum control, including recursive nuclear spin initialization (achieving 77% polarization) and double quantum Ramsey spectroscopy.
Integrated Compensation: Systematic shifts due to temperature and magnetic field fluctuations were actively subtracted using the same NV ensemble operating simultaneously as a comagnetometer and cothermometer.
Performance Metrics: The sensor achieved a rotation noise floor of 52 deg/s/sqrt(Hz) and demonstrated linear scaling with applied rotation rates up to ±107 deg/s.
Material Requirement: Replication and scaling of this technology require high-quality, low-strain Single Crystal Diamond (SCD) substrates with precise (111) orientation and controlled nitrogen doping (approx. 1 ppm NV concentration).

Technical Specifications

The following hard data points were extracted from the experimental results and setup details:

Parameter	Value	Unit	Context
Sensing Element	$^{14}$N Nuclear Spin Ensemble (I=1)	N/A	Embedded in NV centers
Diamond Orientation	(111)	N/A	Crystallographic axis for quantization
NV Concentration	~1	ppm	Used in the diamond plate sample
T₂* Coherence Time	2.37	ms	Measured during double quantum Ramsey precession
Gyroscope Noise Floor	52	deg/s/sqrt(Hz)	Estimated from the Power Spectral Density (PSD)
Comagnetometer Noise Floor	10	nT/sqrt(Hz)	Used for magnetic field compensation
Measured Rotation Range	Up to ±107	deg/s	Calibrated rotation speeds on the turntable
Laser Wavelength	520	nm	Green laser for optical pumping and readout
Laser Power	100	mW	Used for the WSLD-520-001-2 diode
Magnetic Field (B₀)	~10	Gauss	Applied along the (111) axis (7200 Hz Ramsey beating frequency)
Maximum Nuclear Polarization	77 ± 1	%	Achieved via recursive population transfer

Key Methodologies

The gyroscopic measurement relies on precise control of the NV electron and nuclear spins, coupled with sophisticated systematic error correction.

Material Selection and Setup:
- A diamond plate polished perpendicular to the (111) crystallographic axis, containing an ensemble of NV centers (~1 ppm), was used.
- A constant magnetic field (B₀) was applied along the (111) axis using Helmholtz coils.
Nuclear Spin Polarization (Initialization):
- A recursive transfer of population sequence was employed to polarize the $^{14}$N nuclear spin ensemble into the m_I = 0 state.
- This involved spectrally narrow Microwave (MW) $\pi$ pulses and a spectrally broad Radiofrequency (RF) $\pi$ pulse, repeated four times, achieving 77% polarization.
Rotation Sensing (Free Precession):
- The rotation signal was acquired by monitoring the free precession of the $^{14}$N nuclear spin ensemble in the electron spin m_s = 0 subdomain.
- This was performed using Double Quantum (DQ) Ramsey spectroscopy, where rotation induces a pseudomagnetic field shift ($\Omega$).
Nuclear Spin Readout:
- The nuclear spin state was converted into a measurable fluorescence contrast signal using a selective MW $\pi$ pulse applied to the central m_I = 0 peak of the ODMR triplet.
- Referenced readout, utilizing an added RF pulse, doubled the fluorescence contrast and subtracted laser/MW power fluctuations.
Systematic Shift Compensation:
- The same NV ensemble was used in an interleaved fashion as a comagnetometer and cothermometer.
- Digital frequency modulation was used to measure both Electron Spin Resonance (ESR) transitions (m_s = -1 and m_s = 1) to extract magnetic field and temperature values for feedback subtraction.
Calibration Platform:
- The entire optical and electronic setup (including laser, FPGA, MW/RF equipment, and battery power) was mounted on a 360° high-load turntable for autonomous rotation and calibration against a commercial MEMS gyroscope.

6CCVD Solutions & Capabilities

This research highlights the critical need for high-quality, customized diamond substrates to advance solid-state quantum sensing. 6CCVD is uniquely positioned to supply the materials and engineering services required to replicate and scale this NV gyroscope technology.

Requirement from Research Paper	6CCVD Solution & Capability	Technical Advantage for Quantum Sensing
High-Purity Substrate	Optical Grade Single Crystal Diamond (SCD)	Low strain and minimal defects are essential for maximizing the T₂* coherence time (2.37 ms achieved), which directly dictates gyroscope sensitivity.
Specific Crystal Orientation	Custom (111) Orientation Plates	We guarantee precise orientation control, critical for aligning the NV center quantization axis with the applied magnetic field (B₀) and rotation axis.
Controlled NV Ensemble Density	Nitrogen Doping Control (1 ppm range)	Our MPCVD process allows for precise, repeatable control of nitrogen incorporation, optimizing the ensemble size for maximum signal contrast and polarization fidelity (77% achieved).
Scaling and Integration	Custom Dimensions & Thickness	We supply SCD wafers from 0.1 µm up to 500 µm thick, and substrates up to 10 mm thick, accommodating both laboratory prototypes and future chip-scale integration up to 125 mm (PCD).
On-Chip Antenna Integration	In-House Metalization Services	The experiment utilized external MW and RF antennas. 6CCVD offers internal deposition of Au, Pt, Pd, Ti, W, and Cu for robust, high-frequency on-chip antenna structures, enabling compact device fabrication.
Surface Quality for Optics	Ultra-Low Roughness Polishing	SCD polishing to R_a < 1 nm minimizes scattering losses for the 520 nm excitation laser and maximizes fluorescence collection efficiency, improving the signal-to-noise ratio.

Engineering Support

The realization of a compact, low-drift gyroscope requires precise material engineering. 6CCVD’s in-house PhD team specializes in optimizing diamond properties for quantum applications. We offer consultation on:

NV Density Optimization: Balancing ensemble size (signal strength) against spin-spin interactions (coherence time).
Surface Termination: Selecting appropriate surface treatments to maintain NV stability and minimize surface noise.
Integrated Device Design: Assisting with the design and implementation of metalized antenna structures for efficient MW/RF delivery on the diamond surface.

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

View Original Abstract

A rotation sensor is one of the key elements of inertial navigation systems and compliments most cell phone sensor sets used for various applications. Currently, inexpensive and efficient solutions are mechanoelectronic devices, which nevertheless lack long-term stability. Realization of rotation sensors based on spins of fundamental particles may become a drift-free alternative to such devices. Here, we carry out a proof-of-concept experiment, demonstrating rotation measurements on a rotating setup utilizing nuclear spins of an ensemble of nitrogen vacancy centers as a sensing element with no stationary reference. The measurement is verified by a commercially available microelectromechanical system gyroscope.

Tech Support

Original Source

DOI: https://doi.org/10.1103/physrevlett.126.197702

References

2019 - XXV International Congress Of Aeronautics And Astronautics, Italian Association of Aeronautics and Astronautics
1988 - 34th International Instrumentation Symposium, Instrument Society of America
2014 - The Fiber-Optic Gyroscope, Second Edition