Abstract
The magneto-optical Kerr effect (MOKE), the differential reflection of oppositely circularly polarized light, has traditionally been associated with relativistic spin-orbit coupling (SOC), which links a particle’s spin with its orbital motion. In ferromagnets, large MOKE signals arise from the combination of magnetization and SOC, while in certain coplanar antiferromagnets, SOC-induced Berry curvature enables MOKE despite zero net magnetization. Theoretically, large MOKE can also arise in a broader class of magnetic materials with compensated spins, without relying on SOC - for example, in systems exhibiting real-space scalar spin chirality. The experimental verification has remained elusive. Here, we demonstrate such a SOC- and magnetization-free MOKE in the noncoplanar antiferromagnet Co1/3TaS2. Using a Sagnac interferometer microscope, we image domains of scalar spin chirality and their reversal. Our findings establish experimentally a new mechanism for generating large MOKE signals and position chiral spin textures in compensated magnets as a compelling platform for ultrafast, stray-field-immune opto-spintronic applications.
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References
Faraday, M. Experimental researches in electricity.-Nineteenth series. Philos. Trans. R. Soc. 136, 1–20 (1846).
Kerr, J. On rotation of the plane of polarization by reflection from the pole of a magnet. Lond., Edinb., Dublin Philos. Mag. J. Sci. 3, 321–343 (1877).
Qiu, Z. Surface magneto-optic Kerr effect (SMOKE). J. Magn. Magn. Mater. 200, 664–678 (1999).
Kirilyuk, A., Kimel, A. V. & Rasing, T. Ultrafast optical manipulation of magnetic order. Rev. Mod. Phys. 82, 2731–2784 (2010).
Mansuripur, M. The Physical Principles of Magneto-Optical Recording. https://doi.org/10.1017/CBO9780511622472 (Cambridge University Press, 1995).
Gong, C. et al. Discovery of intrinsic ferromagnetism in two-dimensional van der Waals crystals. Nature 546, 265–269 (2017).
Huang, B. et al. Layer-dependent ferromagnetism in a van der Waals crystal down to the monolayer limit. Nature 546, 270–273 (2017).
Thomas, L. H. The Motion of the Spinning Electron. Nature 117, 514–514 (1926).
Fröhlich, J. & Studer, U. M. Gauge invariance and current algebra in nonrelativistic many-body theory. Rev. Mod. Phys. 65, 733–802 (1993).
Argyres, P. N. Theory of the Faraday and Kerr Effects in Ferromagnetics. Phys. Rev. 97, 334–345 (1955).
Chen, H., Niu, Q. & MacDonald, A. H. Anomalous Hall Effect Arising from Noncollinear Antiferromagnetism. Phys. Rev. Lett. 112, 017205 (2014).
Feng, W., Guo, G.-Y., Zhou, J., Yao, Y. & Niu, Q. Large magneto-optical Kerr effect in noncollinear antiferromagnets Mn3 X (X = Rh, Ir, Pt). Phys. Rev. B 92, 144426 (2015).
Higo, T. et al. Large magneto-optical Kerr effect and imaging of magnetic octupole domains in an antiferromagnetic metal. Nat. Photon 12, 73–78 (2018).
Xia, J., Maeno, Y., Beyersdorf, P. T., Fejer, M. M. & Kapitulnik, A. High resolution polar Kerr effect measurements of Sr2RuO4: Evidence for broken time-reversal symmetry in the superconducting state. Phys. Rev. Lett. 97, 167002 (2006).
Schemm, E. R., Gannon, W. J., Wishne, C. M., Halperin, W. P. & Kapitulnik, A. Observation of broken time-reversal symmetry in the heavy-fermion superconductor UPt3. Science 345, 190–193 (2014).
Gong, X. et al. Time-reversal symmetry-breaking superconductivity in epitaxial bismuth/nickel bilayers. Sci. Adv. 3, e1602579 (2017).
Choi, Y.-G. et al. Observation of the orbital Hall effect in a light metal Ti. Nature 619, 52–56 (2023).
Mazin, I. The PRX Editors. Editorial: Altermagnetism-A New Punch Line of Fundamental Magnetism. Phys. Rev. X 12, 040002 (2022).
Amin, O. J. et al. Nanoscale imaging and control of altermagnetism in MnTe. Nature 636, 348–353 (2024).
Jungwirth, T., Marti, X., Wadley, P. & Wunderlich, J. Antiferromagnetic spintronics. Nat. Nanotech. 11, 231–241 (2016).
Baltz, V. et al. Antiferromagnetic spintronics. Rev. Mod. Phys. 90, 015005 (2018).
Šmejkal, L., Mokrousov, Y., Yan, B. & MacDonald, A. H. Topological antiferromagnetic spintronics. Nat. Phys. 14, 242–251 (2018).
He, Q. L., Hughes, T. L., Armitage, N. P., Tokura, Y. & Wang, K. L. Topological spintronics and magnetoelectronics. Nat. Mater. 21, 15–23 (2022).
Feng, W. et al. Topological magneto-optical effects and their quantization in noncoplanar antiferromagnets. Nat. Commun. 11, 118 (2020).
Zhang, S.-S., Ishizuka, H., Zhang, H., Halász, G. B. & Batista, C. D. Real-space Berry curvature of itinerant electron systems with spin-orbit interaction. Phys. Rev. B 101, 024420 (2020).
Zhou, X., Feng, W., Yang, X., Guo, G.-Y. & Yao, Y. Crystal chirality magneto-optical effects in collinear antiferromagnets. Phys. Rev. B 104, 024401 (2021).
Vanderbilt, D. Berry Phases in Electronic Structure Theory (Cambridge University Press, Cambridge, 2018).
Park, P. et al. Field-tunable toroidal moment and anomalous Hall effect in noncollinear antiferromagnetic Weyl semimetal Co1/3TaS2. npj Quantum Mater. 7, 42 (2022).
Park, P. et al. Tetrahedral triple-Q magnetic ordering and large spontaneous Hall conductivity in the metallic triangular antiferromagnet Co1/3TaS2. Nat. Commun. 14, 8346 (2023).
Takagi, H. et al. Spontaneous topological Hall effect induced by non-coplanar antiferromagnetic order in intercalated van der Waals materials. Nat. Phys. 19, 961–968 (2023).
Parkin, S. S. P. & Friend, R. H. 3d transition-metal intercalates of the niobium and tantalum dichalcogenides. I. Magnetic properties. Philos. Mag. B 41, 65–93 (1980).
Miyadai, T. et al. Magnetic properties of Cr1/3NbS2. J. Phys. Soc. Jpn. 52, 1394–1401 (1983).
Parkin, S. S. P., Marseglia, E. A. & Brown, P. J. Magnetic structure of Co1/3NbS2 and Co1/3TaS2. J. Phys. C: Solid State Phys. 16, 2765–2778 (1983).
Morosan, E. et al. Sharp switching of the magnetization in Fe1∕4TaS2. Phys. Rev. B 75, 104401 (2007).
Xie, L. S., Husremović, S., Gonzalez, O., Craig, I. M. & Bediako, D. K. Structure and Magnetism of Iron- and Chromium-Intercalated Niobium and Tantalum Disulfides. J. Am. Chem. Soc. 144, 9525–9542 (2022).
Wu, S. et al. Highly Tunable Magnetic Phases in Transition-Metal Dichalcogenide Fe1/3+δNbS2. Phys. Rev. X 12 (2022).
Ghimire, N. J. et al. Large anomalous Hall effect in the chiral-lattice antiferromagnet CoNb3S6. Nat. Commun. 9, 3280 (2018).
Khanh, N. D. et al. Gapped nodal planes and large topological Nernst effect in the chiral lattice antiferromagnet CoNb3S6. Nat. Commun. 16, 2654 (2025).
Cheong, S.-W. & Huang, F.-T. Altermagnetism with non-collinear spins. npj Quantum Mater. 9, 1–6 (2024).
Xia, J. et al. Polar Kerr-effect measurements of the high-temperature YBa2Cu3O6+x superconductor: Evidence for broken symmetry near the pseudogap temperature. Phys. Rev. Lett. 100, 127002 (2008).
Thomas, S. et al. Localized Control of Curie Temperature in Perovskite Oxide Film by Capping-Layer-Induced Octahedral Distortion. Phys. Rev. Lett. 119, 177203 (2017).
Feng, Z. et al. Nonvolatile Nematic Order Manipulated by Strain and Magnetic Field in a Layered Antiferromagnet. Preprint at https://doi.org/10.48550/arXiv.2507.05486 (2025).
Xia, J., Beyersdorf, P. T., Fejer, M. M. & Kapitulnik, A. Modified Sagnac interferometer for high-sensitivity magneto-optic measurements at cryogenic temperatures. Appl Phys. Lett. 89, 062508 (2006).
Onsager, L. Reciprocal Relations in Irreversible Processes. I. Phys. Rev. 37, 405–426 (1931).
Nakatsuji, S., Kiyohara, N. & Higo, T. Large anomalous Hall effect in a non-collinear antiferromagnet at room temperature. Nature 527, 212–215 (2015).
Farhang, C. et al. Temperature-invariant magneto-optical Kerr effect in a noncollinear antiferromagnet. Preprint at https://doi.org/10.48550/arxiv.2510.19709 (2025).
Kim, M., Freeman, A. J. & Wu, R. Surface effects and structural dependence of magneto-optical spectra: Ultrathin Co films and CoPt n alloys and multilayers. Phys. Rev. B 59, 9432–9436 (1999).
Park, P. et al. Composition dependence of bulk properties in the Co-intercalated transition metal dichalcogenide Co1/3TaS2. Phys. Rev. B 109, L060403 (2024).
Verma, N., Addison, Z. & Randeria, M. Unified theory of the anomalous and topological Hall effects with phase-space Berry curvatures. Sci. Adv. 8, (2022).
Erskine, J. L. & Stern, E. A. Magneto-optic Kerr Effect in Ni, Co, and Fe. Phys. Rev. Lett. 30, 1329–1332 (1973).
Kato, Y. D., Okamura, Y., Hirschberger, M., Tokura, Y. & Takahashi, Y. Topological magneto-optical effect from skyrmion lattice. Nat. Commun. 14, 5416 (2023).
Li, X. et al. Topological Kerr effects in two-dimensional magnets with broken inversion symmetry. Nat. Phys. 20, 1145–1151 (2024).
Cai, M. et al. Topological Magneto-optical Effect from Skyrmions in Two-Dimensional Ferromagnets. ACS Nano 18, 20055–20064 (2024).
Acknowledgements
We thank J.G. Zheng for Energy-dispersive X-ray spectroscopy (EDX) at UC Irvine. This project was supported by NSF award DMR-2419425 and the Gordon and Betty Moore Foundation EPiQS Initiative, Grant # GBMF10276 awarded to J.X.; The work at Rutgers University was supported by the DOE under Grant No. DOE: DE-FG02-07ER46382 awarded to S.W.C.; J.Y. acknowledges support by DOE under Grant No. DOE: DE-SC0021188 awarded to J.Y.; The authors acknowledge the use of facilities and instrumentation at the UC Irvine Materials Research Institute (IMRI), which is supported in part by the National Science Foundation through the UC Irvine Materials Research Science and Engineering Center (DMR-2011967).
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J.X. conceived and supervised the project. C.F., W.L., and J.X. carried out the optical measurements. K.D., Y.G., J.Y., and S.W.C. grew the crystals and carried out transport, magnetization, and magnetic force microscopy measurements. J.X. drafted the paper with the input from all authors. All authors contributed to the discussion of the manuscript.
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Farhang, C., Lu, W., Du, K. et al. Topological magneto-optical Kerr effect without spin-orbit coupling in spin-compensated antiferromagnet. Nat Commun (2026). https://doi.org/10.1038/s41467-026-70238-0
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DOI: https://doi.org/10.1038/s41467-026-70238-0
