Photoswitchable radicals as reporter spins for quantum sensing with spin defects in diamond

Fuente: arXiv
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Bibliographic Details
Main Authors: Ajayakumar, Lakshmy Priya, Durden, David J., Regeni, Aksshay Nandakumar, Xie, Mingcai, Hegde, Swastik, Aldas, Gustavo, Haggard, Kyle, Backlund, Mikael P.
Format: Preprint
Published: 2025
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author Ajayakumar, Lakshmy Priya
Durden, David J.
Regeni, Aksshay Nandakumar
Xie, Mingcai
Hegde, Swastik
Aldas, Gustavo
Haggard, Kyle
Backlund, Mikael P.
author_facet Ajayakumar, Lakshmy Priya
Durden, David J.
Regeni, Aksshay Nandakumar
Xie, Mingcai
Hegde, Swastik
Aldas, Gustavo
Haggard, Kyle
Backlund, Mikael P.
contents The rapid decay of target signal strength with distance from the sensor presents a key challenge in nanoscale magnetic sensing with nitrogen-vacancy (NV) centers in diamond, limiting both sensitivity and spatial resolution. Here we introduce a strategy to overcome this limitation by using radical anions formed from rhodamine-derived dyes as reporter spins localized to the diamond surface. These radicals, generated through photoreduction, are optically identifiable and stable on timescales exceeding an hour. We experimentally demonstrate their coherent manipulation and detection using single, shallow NV centers for readout. We observe heterogeneity in the local magnetic environments of the photoactivated spins from site to site, likely due to variations in inter-radical couplings across our measurements. Looking forward, our approach enables correlative nanoscale magnetic and optical imaging, and opens new pathways toward single-molecule magnetic resonance studies.
format Preprint
id arxiv_https___arxiv_org_abs_2510_05406
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Photoswitchable radicals as reporter spins for quantum sensing with spin defects in diamond
Ajayakumar, Lakshmy Priya
Durden, David J.
Regeni, Aksshay Nandakumar
Xie, Mingcai
Hegde, Swastik
Aldas, Gustavo
Haggard, Kyle
Backlund, Mikael P.
Quantum Physics
Chemical Physics
The rapid decay of target signal strength with distance from the sensor presents a key challenge in nanoscale magnetic sensing with nitrogen-vacancy (NV) centers in diamond, limiting both sensitivity and spatial resolution. Here we introduce a strategy to overcome this limitation by using radical anions formed from rhodamine-derived dyes as reporter spins localized to the diamond surface. These radicals, generated through photoreduction, are optically identifiable and stable on timescales exceeding an hour. We experimentally demonstrate their coherent manipulation and detection using single, shallow NV centers for readout. We observe heterogeneity in the local magnetic environments of the photoactivated spins from site to site, likely due to variations in inter-radical couplings across our measurements. Looking forward, our approach enables correlative nanoscale magnetic and optical imaging, and opens new pathways toward single-molecule magnetic resonance studies.
title Photoswitchable radicals as reporter spins for quantum sensing with spin defects in diamond
topic Quantum Physics
Chemical Physics
url https://arxiv.org/abs/2510.05406