Spin-manipulated nanoscopy for single nitrogen-vacancy center localizations in nanodiamonds

At a Glance

Metadata	Details
Publication Date	2017-05-10
Journal	Light Science & Applications
Authors	Martina Barbiero, Stefania Castelletto, Xiaosong Gan, Miṅ Gu
Institutions	Swinburne University of Technology, RMIT University
Citations	27
Analysis	Full AI Review Included

Technical Analysis & Documentation: Spin-Manipulated Nanoscopy using NV Centers

Executive Summary

This documentation analyzes a study demonstrating spin-manipulated nanoscopy (SMN) to achieve super-resolution imaging of collectively blinking Nitrogen-Vacancy (NV^-) centers confined within nanodiamonds (NDs). This method significantly advances the field of quantum sensing and nanoscale imaging.

Core Achievement: Successfully resolved two coupled, collectively blinking NV^- centers, separated by distances as small as 23 nm to 27 nm, overcoming the diffraction limit.
Methodology: SMN combines wide-field localization microscopy with nanoscale spin manipulation, utilizing Optically Detected Magnetic Resonance (ODMR) via synchronized microwave (MW) excitation.
Key Mechanism: Applying the resonant MW frequency partially suppresses the cooperative emissions of the blinkers, enabling the three-level blinking dynamics (two emitters ‘on’, one ‘on’, or both ‘off’) to be distinguished and localized individually.
Material Input: The study utilized oxidized High-Pressure High-Temperature (HPHT) NDs (average size 42 nm), chosen because the reduced size promotes the necessary blinking phenomenon via electron tunneling to the surface.
Quantum Sensing Integration: The technique successfully localizes the magnetic spin states (m_s = ±1) of individual NV centers by applying an external 10 Gauss magnetic field to split the overlapping ODMR dips.
Relevance: The technology offers a new platform for studying spin-related quantum interactions and is highly applicable to advanced biomedical imaging and quantum computation development.

Technical Specifications

Extracted operational and performance parameters from the research:

Parameter	Value	Unit	Context
ND Starting Size (HPHT)	70	nm	Average size before oxidation
ND Final Size (Post-Oxidation)	42	nm	Average size enabling enhanced blinking
Excitation Wavelength (PL)	532	nm	Linearly polarized beam
Objective Numerical Aperture	1.4	NA	Oil immersion objective
ODMR Frequency Range	2.6 to 3.0	GHz	Microwave frequency used for spin manipulation
ODMR Frequency Increment	0.8	MHz	Step size for ODMR measurement acquisition
Applied External B Field	10	Gauss	Used to split overlapping resonant ODMR dips
Blinking Cycles Recorded	500	Cycles	Total measurement length at ODMR frequency
Single NV FWHM Resolution	34	nm	Full Width at Half Maximum achieved for localized single NV
Resolved NV Separation Distance	23, 27	nm	Distance between two resolved NV^- emitters
HBT Second-Order Correlation (g²(0))	0.5	Dimensionless	Confirms the presence of two NV centers
Oxidation Temperature (Stage 1)	450	°C	2 hour duration to remove surface carbon
Oxidation Temperature (Stage 2)	600	°C	20 minute duration

Key Methodologies

The experiment relies on precise material preparation and synchronization of optical and microwave inputs:

Material Preparation & Size Reduction:
- HPHT nanodiamonds (70 nm average) were drop-cast onto plasma-cleaned borosilicate coverslips.
- A two-step oxidation process (450 °C for 2h, then 600 °C for 20 min) was implemented to reduce the ND size (to ~42 nm average), concentrating the NV centers near the surface to promote photoexcited electron tunneling and the required blinking phenomenon.
Wide-Field ODMR Setup:
- The setup combined wide-field localization microscopy with ODMR capability. Fluorescence was collected by a 1.4 NA oil objective and detected by a cooled EMCCD camera (-80 °C).
- Microwave (MW) signals (2.6-3.0 GHz) were delivered via a conductive pattern imprinted directly on the coverslip, synchronized with the camera exposure time (30 ms per frame).
Spin-Manipulated Localization:
- The MW source was tuned to the ODMR frequency (f_ODMR) to induce the spin transition (m_s = 0 → m_s = ±1). This resonant excitation partially suppresses collective blinking.
- When the MW is applied, the fluorescence trace shows three intensity levels, corresponding to (Two ‘on’), (One ‘on’), and (Both ‘off’).
Data Selection and Reconstruction:
- Only image frames corresponding to the “one emitter in the ‘on’ state” were selected for localization.
- The QuickPALM algorithm with Gaussian fitting was used to determine the position of each NV center, achieving 34 nm FWHM resolution for single emitters.
External Field Application:
- When the two NV centers possessed overlapping ODMR frequencies, an external magnetic field of 10 Gauss was applied. This Zeeman splitting separated the resonant dips, allowing each NV center to be addressed individually for resolution (27 nm separation resolved).

6CCVD Solutions & Capabilities

This research highlights the necessity of extremely high-quality, defect-controlled diamond materials and precise engineering capabilities—fields where 6CCVD excels. Replication and extension of this research require materials suitable for advanced quantum chip integration.

Research Requirement	6CCVD Material/Capability	Engineering Value Proposition
Material Foundation for NV Creation	Optical Grade Single Crystal Diamond (SCD): SCD wafers (0.1µm - 500µm thick) offer ultra-low strain and high purity, essential for reproducible NV creation (via ion implantation/annealing, or acting as large precursors).	Ensures high crystalline quality, minimizing decoherence and maximizing the coherence time (T₂) necessary for robust quantum sensing applications.
MW Delivery Integration	Custom Metalization Services (Ti/Pt/Au, W/Cu): Capability to deposit precise metallic patterns directly onto the diamond surface (used as a chip, rather than a coverslip).	Facilitates scalable, on-chip integration of microwave coplanar waveguides (CPWs) for highly efficient, uniform ODMR excitation and spin control.
High Surface Quality for Nanoscopy	Atomic-Scale Polishing: Achieves surface roughness Ra < 1 nm on SCD material.	Critical for super-resolution experiments, minimizing surface scattering losses and enhancing optical coupling fidelity (required for the 1.4 NA immersion objective used).
Custom Platform Dimensions	Custom SCD/PCD Plates up to 125 mm: Substrate thickness up to 10 mm available. Precision laser cutting services provided.	Supports the transition from R&D setups (coverslips) to stable, larger-format diamond quantum chips integrated into specialized cryogenic or high-power microscopy systems.
Material Recommendation for Extension:	High-Purity Single Crystal Diamond (SCD) Wafers: Recommended for platforms seeking controlled NV depth and density, surpassing the limitations of size-reduced HPHT nanodiamonds.	Provides a stable, non-blinking substrate for surface-enhanced applications or for creating defined, shallow NV ensembles required for surface-proximal sensing.

Engineering Support

6CCVD’s in-house PhD team provides specialized consultation for projects focused on nanoscale magnetic resonance and super-resolution quantum imaging. We assist engineers and researchers in selecting the optimal MPCVD diamond material, specifying critical parameters (like nitrogen concentration, material thickness, and doping levels for BDD applications), and designing the appropriate metalization schemes to replicate or extend the capabilities demonstrated in this Spin-Manipulated Nanoscopy research.

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

Tech Support

Original Source

DOI: https://doi.org/10.1038/lsa.2017.85