Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:2411.12243 · Advanced Optical Materials

Magnetic Steganography Based on Wide‐Field Diamond Quantum Microscopy

Jungbae Yoon, Jugyeong Chung, Hyunjun Jang, Jinsu Jung, Yuhan Lee, Chulki Kim, Nojoon Myoung, Donghun Lee

Published May 12, 2025• 0 citations
arXivHTMLPDF

Abstract

Abstract Magnetic steganography using wide‐field quantum microscopy based on diamond nitrogen‐vacancy (NV) centers is experimentally demonstrated. The method offers magnetic imaging capable of revealing concealed information otherwise invisible with conventional optical measurements. For a proof‐of‐principle demonstration of magnetic steganography, micrometer structures designed as pixel arts, barcodes, and QR codes are fabricated using mixtures of magnetic and non‐magnetic materials: Ni and Au. Three different imaging modes based on the changes in frequency, linewidth, and contrast of the NV's electron spin resonance are compared and find that the last mode offers the best quality for reconstructing hidden magnetic images. By simultaneous driving of the NV's qutrit states with two independent microwave fields, the imaging time is expedited by a factor of three. This work shows potential applications of quantum magnetic imaging in the field of image steganography.

DOI
10.1002/adom.202501161

Related papers

Magnetic Steganography Based on Wide‐Field Diamond Quantum Microscopy (Advanced Optical Materials 24/2025)

Jungbae Yoon, Jugyeong Chung, Hyunjun Jang +5 more

Wide-Field Quantum Microscopy This cover image illustrates magnetic steganography using Nitrogen vacancy defects inside diamonds. Magnetic graphics, including pixel art and QR codes, are produced using magnetic materials and obscured behind patterns manufactured using non-magnetic materials, which were unveiled through widefield quantum microscopy. Furthermore, manipulating the electron spin of NV with dual microwave fields enhanced imaging speed by a factor of three. More details can be found in article 2501161 by Jungbae Yoon, Donghun Lee, and co-workers.

Advanced Optical Materials•Aug 1, 2025•0 citations

Quantum diamond microscope for dynamic imaging of magnetic fields

Jiashen Tang, Zechuan Yin, Connor Hart +6 more

Wide-field imaging of magnetic signals using ensembles of nitrogen-vacancy (NV) centers in diamond has garnered increasing interest due to its combination of micron-scale resolution, millimeter-scale field of view, and compatibility with diverse samples from across the physical and life sciences. Recently, wide-field NV magnetic imaging based on the Ramsey protocol has achieved uniform and enhanced sensitivity compared to conventional measurements. Here, we integrate the Ramsey-based protocol with spin-bath driving to extend the NV spin dephasing time and improve magnetic sensitivity. We also employ a high-speed camera to enable dynamic wide-field magnetic imaging. We benchmark the utility of this quantum diamond microscope (QDM) by imaging magnetic fields produced from a fabricated wire phantom. Over a 270 × 270 μm2 field of view, a median per-pixel magnetic sensitivity of 4.1(1) nT /Hz is realized with a spatial resolution ≲ 10 μm and sub-millisecond temporal resolution. Importantly, the spatial magnetic noise floor can be reduced to the picotesla scale by time-averaging and signal modulation, which enables imaging of a magnetic-field pattern with a peak-to-peak amplitude difference of about 300 pT. Finally, we discuss potential new applications of this dynamic QDM in studying biomineralization and electrically active cells.

arXiv:2309.06587•AVS Quantum Science•Nov 17, 2023•15 citations

Imaging of microwave magnetic field orientation using continuous-wave experiments on nitrogen-vacancy centers in diamond

Akshat Rana, Pooja Lamba, Atanu Ghosh +2 more

Abstract Imaging of microwave magnetic fields with nano-scale resolution has interesting applications. Specifically, detecting the orientation of microwave fields is useful in condensed matter physics and quantum control. However, most of the existing methods for microwave field imaging are limited to detecting the magnitude of the fields. Due to their small sensor size and favorable optical and spin properties, nitrogen-vacancy (NV) centers in diamond are highly suitable for imaging dc and ac magnetic fields. The reported methods for detecting the direction of microwave magnetic fields use pulsed Rabi frequency measurements. Here, we demonstrate imaging of the direction of linearly polarized microwave magnetic fields using only continuous-wave experiments on NV centers. This simplifies the sensor apparatus and is particularly advantageous in applications where pulsing of the target microwave field is not possible. The method requires a static bias magnetic field oriented perpendicular to the quantization axis of NV centers. We detect the direction of an arbitrary microwave magnetic field using NV centers of two different orientations of an NV ensemble. Moreover, we demonstrate that the projection of the microwave fields onto a plane can be imaged using NV centers of a single orientation. This can be straightforwardly implemented using a single NV center.

arXiv:2506.17695•Journal of Physics D Applied Physics•Oct 9, 2025•0 citations

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

Jean-Christophe Jaskula, Erik Bauch, Silvia Arroyo-Camejo +4 more

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.

arXiv:1610.02097•Optics Express•May 3, 2017•51 citations

High-resolution wide-field magnetic imaging with sparse sampling using nitrogen-vacancy centers

Keqing Liu, Jiazhao Tian, Bokun Duan +7 more

Nitrogen-vacancy (NV) centers in diamond enable quantitative magnetic imaging, yet practical implementations must balance spatial resolution against acquisition time (and thus per-pixel sensitivity). Single-NV scanning magnetometry achieves genuine nanoscale resolution, nonetheless requires typically a slow pixel-by-pixel acquisition. Meanwhile, wide-field NV-ensemble microscopy provides parallel readout over a large field of view, however is jointly limited by the optical diffraction limit and the sensor-sample standoff. Here, we present a sparse-sampling strategy for reconstructing high-resolution wide-field images from only a small number of measurements. Using simulated NV-ensemble detection of ac magnetic fields, we show that a mean-adjusted Bayesian estimation (MABE) framework can reconstruct 10000-pixel images from only 25 sampling points, achieving SSIM values exceeding 0.999 for representative smooth field distributions, while optimized dynamical-decoupling pulse sequences yield an approximately twofold improvement in magnetic-field sensitivity. The method further clarifies how sampling patterns and sampling density affect reconstruction accuracy and suggests a route toward faster and more scalable magnetic-imaging architectures that may extend to point-scanning NV sensors and other magnetometry platforms, such as SQUIDs, Hall probes, and magnetic tunnel junctions.

quant-pharXiv:2602.00679•Feb 3, 2026

In-Substrate Imaging of Diamond hBN FET Current via Widefield Quantum Diamond Microscopy

Anuj Bathla, Subrat Kumar Pradhan, Ajit Kumar Dash +7 more

We demonstrate widefield magnetic imaging of current flow in hydrogen terminated diamond field effect transistors (FETs) through in-substrate nitrogen vacancy (NV) centers. Hydrogen termination of the diamond surface induces a two dimensional hole gas (2DHG), while an ensemble of near surface NV centers located $ \sim 1~μm$ below the surface enables noninvasive magnetic imaging of current flow with micrometer scale spatial resolution. The FETs were electrically characterized over a range of drain source biases $V_{ds}= 0$ to $-15V$ and gate voltages,$V_{gs}= +3$ to $-9V$ followed by in situ widefield NV magnetometry during device operation. Magnetic field maps and reconstructed current density distributions directly visualize current injection at the source drain contacts and transport beneath the hBN gated channel. Magnetic field maps reveal current density variations in the channel region owing to non-uniformities or defects in the gate dielectric. In addition, we observe a pronounced enhancement of the drain current ($\sim 600-900 μA$) and a shift in the apparent threshold voltage during laser illumination, reflecting photo induced changes in channel electrostatics. By correlating gate dependent magnetic images with simultaneous electrical measurements, we directly link spatial current distributions to FET transfer characteristics, providing new insight into buried interface transport and non-uniform gating effects in the transistor channel. As the methodology is compatible with top gated FETs, it can be used to map channel current distributions with micrometer resolution in emerging channel materials, such as 2D materials and wide bandgap channels, and establish widefield NV magnetometry as a powerful platform for probing charge transport in transistors and Van der Waals dielectric heterostructures.

cond-mat.mes-hallCross-listedarXiv:2601.15355•Jan 22, 2026
Abstract Magnetic steganography using wide‐field quantum microscopy based on diamond nitrogen‐vacancy (NV) centers is experimentally demonstrated. The method offers magnetic imaging capable of revealing concealed information otherwise invisible with conventional optical measurements. For a proof‐of‐principle demonstration of magnetic steganography, micrometer structures designed as pixel arts, barcodes, and QR codes are fabricated using mixtures of magnetic and non‐magnetic materials: Ni and Au. Three different imaging modes based on the changes in frequency, linewidth, and contrast of the NV's electron spin resonance are compared and find that the last mode offers the best quality for reconstructing hidden magnetic images. By simultaneous driving of the NV's qutrit states with two independent microwave fields, the imaging time is expedited by a factor of three. This work shows potential applications of quantum magnetic imaging in the field of image steganography.
Wide-Field Quantum Microscopy This cover image illustrates magnetic steganography using Nitrogen vacancy defects inside diamonds. Magnetic graphics, including pixel art and QR codes, are produced using magnetic materials and obscured behind patterns manufactured using non-magnetic materials, which were unveiled through widefield quantum microscopy. Furthermore, manipulating the electron spin of NV with dual microwave fields enhanced imaging speed by a factor of three. More details can be found in article 2501161 by Jungbae Yoon, Donghun Lee, and co-workers.
Wide-field imaging of magnetic signals using ensembles of nitrogen-vacancy (NV) centers in diamond has garnered increasing interest due to its combination of micron-scale resolution, millimeter-scale field of view, and compatibility with diverse samples from across the physical and life sciences. Recently, wide-field NV magnetic imaging based on the Ramsey protocol has achieved uniform and enhanced sensitivity compared to conventional measurements. Here, we integrate the Ramsey-based protocol with spin-bath driving to extend the NV spin dephasing time and improve magnetic sensitivity. We also employ a high-speed camera to enable dynamic wide-field magnetic imaging. We benchmark the utility of this quantum diamond microscope (QDM) by imaging magnetic fields produced from a fabricated wire phantom. Over a 270 × 270 μm2 field of view, a median per-pixel magnetic sensitivity of 4.1(1) nT /Hz is realized with a spatial resolution ≲ 10 μm and sub-millisecond temporal resolution. Importantly, the spatial magnetic noise floor can be reduced to the picotesla scale by time-averaging and signal modulation, which enables imaging of a magnetic-field pattern with a peak-to-peak amplitude difference of about 300 pT. Finally, we discuss potential new applications of this dynamic QDM in studying biomineralization and electrically active cells.
Abstract Imaging of microwave magnetic fields with nano-scale resolution has interesting applications. Specifically, detecting the orientation of microwave fields is useful in condensed matter physics and quantum control. However, most of the existing methods for microwave field imaging are limited to detecting the magnitude of the fields. Due to their small sensor size and favorable optical and spin properties, nitrogen-vacancy (NV) centers in diamond are highly suitable for imaging dc and ac magnetic fields. The reported methods for detecting the direction of microwave magnetic fields use pulsed Rabi frequency measurements. Here, we demonstrate imaging of the direction of linearly polarized microwave magnetic fields using only continuous-wave experiments on NV centers. This simplifies the sensor apparatus and is particularly advantageous in applications where pulsing of the target microwave field is not possible. The method requires a static bias magnetic field oriented perpendicular to the quantization axis of NV centers. We detect the direction of an arbitrary microwave magnetic field using NV centers of two different orientations of an NV ensemble. Moreover, we demonstrate that the projection of the microwave fields onto a plane can be imaged using NV centers of a single orientation. This can be straightforwardly implemented using a single NV center.
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.
Nitrogen-vacancy (NV) centers in diamond enable quantitative magnetic imaging, yet practical implementations must balance spatial resolution against acquisition time (and thus per-pixel sensitivity). Single-NV scanning magnetometry achieves genuine nanoscale resolution, nonetheless requires typically a slow pixel-by-pixel acquisition. Meanwhile, wide-field NV-ensemble microscopy provides parallel readout over a large field of view, however is jointly limited by the optical diffraction limit and the sensor-sample standoff. Here, we present a sparse-sampling strategy for reconstructing high-resolution wide-field images from only a small number of measurements. Using simulated NV-ensemble detection of ac magnetic fields, we show that a mean-adjusted Bayesian estimation (MABE) framework can reconstruct 10000-pixel images from only 25 sampling points, achieving SSIM values exceeding 0.999 for representative smooth field distributions, while optimized dynamical-decoupling pulse sequences yield an approximately twofold improvement in magnetic-field sensitivity. The method further clarifies how sampling patterns and sampling density affect reconstruction accuracy and suggests a route toward faster and more scalable magnetic-imaging architectures that may extend to point-scanning NV sensors and other magnetometry platforms, such as SQUIDs, Hall probes, and magnetic tunnel junctions.
We demonstrate widefield magnetic imaging of current flow in hydrogen terminated diamond field effect transistors (FETs) through in-substrate nitrogen vacancy (NV) centers. Hydrogen termination of the diamond surface induces a two dimensional hole gas (2DHG), while an ensemble of near surface NV centers located $ \sim 1~μm$ below the surface enables noninvasive magnetic imaging of current flow with micrometer scale spatial resolution. The FETs were electrically characterized over a range of drain source biases Vds=0V_{ds}= 0Vds​=0 to −15V-15V−15V and gate voltages,Vgs=+3V_{gs}= +3Vgs​=+3 to −9V-9V−9V followed by in situ widefield NV magnetometry during device operation. Magnetic field maps and reconstructed current density distributions directly visualize current injection at the source drain contacts and transport beneath the hBN gated channel. Magnetic field maps reveal current density variations in the channel region owing to non-uniformities or defects in the gate dielectric. In addition, we observe a pronounced enhancement of the drain current (∼600−900μA\sim 600-900 μA∼600−900μA) and a shift in the apparent threshold voltage during laser illumination, reflecting photo induced changes in channel electrostatics. By correlating gate dependent magnetic images with simultaneous electrical measurements, we directly link spatial current distributions to FET transfer characteristics, providing new insight into buried interface transport and non-uniform gating effects in the transistor channel. As the methodology is compatible with top gated FETs, it can be used to map channel current distributions with micrometer resolution in emerging channel materials, such as 2D materials and wide bandgap channels, and establish widefield NV magnetometry as a powerful platform for probing charge transport in transistors and Van der Waals dielectric heterostructures.