Optical detection of magnetic resonance using quantum spin sensors (QSS) provides a spatially local and sensitive technique to probe spin dynamics in magnets. However, its utility as a probe of antiferromagnetic resonance (AFMR) remains an open question. We report the first experimental demonstration of optically detected AFMR in layered van der Waals antiferromagnets (AF) up to frequencies of 24 GHz. We leverage QSS spin relaxation due to low-frequency magnetic field fluctuations arising from collective dynamics of magnons excited by the uniform AFMR mode. First, through AFMR spectroscopy we characterize the intrinsic exchange fields and magnetic anisotropies of the AF. Second, using the localized sensitivity of the QSS we demonstrate magnon transport over tens of micrometers. Finally, we find that optical detection efficiency increases with increasing frequency. This showcases the dual capabilities of QSS as detectors of high frequency magnetization dynamics and magnon transport, paving the way for understanding and controlling the magnetism of antiferromagnets.
@article{arxiv.2410.23421,
title = {Quantum Sensing of Broadband Spin Dynamics and Magnon Transport in Antiferromagnets},
author = {Alex Lee Melendez and Shekhar Das and Francisco Ayala Rodriguez and I-Hsuan Kao and Wenhao Liu and Archibald J. Williams and Bing Lv and Joshua Goldberger and Shubhayu Chatterjee and Simranjeet Singh and P. Chris Hammel},
journal= {arXiv preprint arXiv:2410.23421},
year = {2025}
}
Comments
Article is 21 pages including 4 figures, supplemental material is 10 pages including 4 figures