Superresolution optical magnetic imaging and spectroscopy using individual electronic spins in diamond

At a Glance

Metadata	Details
Publication Date	2017-05-03
Journal	Optics Express
Authors	Jean-Christophe Jaskula, Erik Bauch, Silvia Arroyo-Camejo, Mikhail D. Lukin, Stefan W. Hell
Institutions	Harvard University, Max Planck Society
Citations	51
Analysis	Full AI Review Included

Technical Documentation & Analysis: Superresolution NV Magnetometry

This document analyzes the research paper “Superresolution optical magnetic imaging and spectroscopy using individual electronic spins in diamond” to provide technical specifications and align the material requirements with 6CCVD’s advanced MPCVD diamond catalog.

Executive Summary

This research successfully demonstrates the use of spin-RESOLFT microscopy combined with Nitrogen Vacancy (NV) centers in isotopically engineered diamond to achieve unprecedented nanoscale magnetic imaging and spectroscopy.

Superresolution Achieved: Lateral resolution down to 20 ± 2 nm was achieved, significantly exceeding the optical diffraction limit for selective addressing of individual NV centers.
Low-Power Operation: The spin-RESOLFT technique operates with optical depletion powers as low as 25 µW, making it suitable for cryogenic or light-sensitive biological applications where high optical power is detrimental.
High-Purity Material: The study relied on ultra-pure, isotopically engineered CVD diamond (up to 99.999% ¹²C) to maximize electronic spin coherence times (T₂ up to ~800 µs).
Nanoscale NMR Sensing: A shallow NV center (localized 3.0 ± 0.3 nm below the surface) was used to detect proton Nuclear Magnetic Resonance (NMR) signals from external immersion oil, achieving 50 nm lateral imaging resolution.
Coherence Extension: Compatibility with dynamic decoupling sequences (XY8-k) was validated, extending the T₂ of shallow NVs up to 100 µs, enabling practical nanoscale NMR imaging.
Versatile Sensing Platform: The methodology is expected to be extended to other NV-based sensing modalities, including temperature, electric field, and charge state detection, all with nanoscale optical resolution.

Technical Specifications

The following hard data points were extracted from the experimental results and material descriptions:

Parameter	Value	Unit	Context
Lateral Resolution (Spin-RESOLFT)	20 ± 2	nm	Achieved with 2.1 µs doughnut pulse duration.
Shallow NV Depth	3.0 ± 0.3	nm	Determined by fitting NV NMR data to an analytical model.
Isotopic Purity (Sample A)	99.99	% ¹²C	Used for bulk T₂ measurements (~800 µs).
Isotopic Purity (Sample B)	99.999	% ¹²C	Used for shallow NV NMR sensing.
Electronic Spin Coherence Time (T₂)	~800	µs	Measured in bulk SCD (Sample A).
Extended T₂ (Shallow NV, XY8-k)	Up to 100	µs	Achieved using dynamic decoupling protocols.
Minimum Optical Depletion Power	25	µW	Required for sub-diffraction NV imaging.
AC Magnetic Field Gradient	~1	nT/nm	Measured difference between two NVs separated by 105 nm.
Static Magnetic Field (B₀)	282	G	Applied for proton NMR detection (Larmor frequency ~1.2 MHz).
Microwave Frequency	2.87	GHz	Used for coherent spin manipulation.
NV Position Stability (Tracking)	11	nm	Standard deviation achieved over 2 hours with temperature stabilization (±0.1 °C).

Key Methodologies

The experiment relied on precise material engineering and advanced optical manipulation techniques:

Material Selection and Engineering: Ultra-pure, isotopically engineered Single Crystal Diamond (SCD) was used. Purity levels of 99.99% ¹²C (Sample A) and 99.999% ¹²C (Sample B) were critical to minimize spin bath decoherence and maximize T₂.
Shallow NV Creation: NV centers were created via shallow ¹⁴N implantation at 2.5 keV, resulting in NV depths ranging from 1 nm to 20 nm, necessary for coupling to external nuclear spins (NMR).
Spin-RESOLFT Setup: A standard NV-diamond scanning confocal microscope was augmented with a low-power green doughnut beam for spatially selective repolarization and superresolution readout.
Coherent Spin Control: Microwave (MW) pulses (at 2.87 GHz) were applied via an external copper wire to perform coherent spin manipulation sequences (e.g., Hahn-echo and XY8-k dynamic decoupling).
AC Magnetometry: A 25 µm diameter copper wire, positioned ~10 µm from the NVs, was driven with an AC current (7 mA at 8.3 kHz) to generate a controlled, spatially varying magnetic field gradient (~1 nT/nm).
Thermal Stabilization: Insulating enclosures were used to minimize laboratory temperature fluctuations to less than 0.1 °C, reducing NV position drift to a standard deviation of 11 nm over long acquisition times.

6CCVD Solutions & Capabilities

The success of this superresolution magnetometry and NMR research hinges entirely on the quality and precise engineering of the diamond material. 6CCVD is uniquely positioned to supply the necessary SCD wafers to replicate and advance this work.

Research Requirement	6CCVD Solution & Capability	Value Proposition
Ultra-High Isotopic Purity	Optical Grade SCD (Single Crystal Diamond): We specialize in MPCVD growth of SCD with customizable isotopic enrichment, offering >99.999% ¹²C purity.	Maximize T₂ Coherence: Directly supports the achievement of long electronic spin coherence times (T₂ > 800 µs) essential for high-sensitivity quantum sensing and NMR applications.
Precise Thickness Control	SCD Wafers (0.1 µm to 500 µm): We provide SCD plates with thickness control down to 0.1 µm.	Optimized Implantation: Ideal for researchers requiring ultra-thin layers for precise shallow NV implantation (e.g., the 3 nm depth used for external NMR coupling).
Surface Quality for Shallow NVs	Ultra-Low Roughness Polishing: SCD polishing capability to achieve Ra < 1 nm.	Minimize Surface Decoherence: Critical for shallow NV applications where surface defects drastically shorten T₂. Our superior polishing ensures minimal T₂ degradation, maximizing sensor sensitivity.
Integration of Sensing Structures	Custom Metalization Services: In-house deposition of Au, Pt, Pd, Ti, W, Cu.	Seamless Integration: We can pre-deposit alignment marks, contact pads, or micro-wire structures (like the AC current wire used in Fig. 3) directly onto the diamond surface, streamlining experimental setup and integration.
Scaling and Custom Dimensions	Custom Dimensions: Plates/wafers up to 125 mm (PCD) and custom SCD sizes.	Future-Proofing Research: Supports the transition from small research samples to larger, integrated systems required for wide-field magnetic imaging or scalable quantum devices.

Engineering Support

6CCVD’s in-house PhD team provides expert consultation on material selection, isotopic purity requirements, and optimal substrate preparation for advanced quantum sensing projects, including nanoscale AC magnetometry and NV-based NMR. We ensure the diamond substrate meets the stringent specifications required for achieving high T₂ and low-power superresolution imaging.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly. We offer global shipping (DDU default, DDP available) to support your research worldwide.

View Original Abstract

Nitrogen vacancy (NV) color centers in diamond are a leading modality for both superresolution optical imaging and nanoscale magnetic field sensing. In this work, we address the key challenge of performing optical magnetic imaging and spectroscopy selectively on multiple NV centers that are located within a diffraction-limited field-of-view. We use spin-RESOLFT microscopy to enable precision nanoscale mapping of magnetic field patterns with resolution down to ~20 nm, while employing a low power optical depletion beam. Moreover, we use a shallow NV to demonstrate the detection of proton nuclear magnetic resonance (NMR) signals exterior to the diamond, with 50 nm lateral imaging resolution and without degrading the proton NMR linewidth.

Tech Support

Original Source

DOI: https://doi.org/10.1364/oe.25.011048