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arXiv · 2212.07221

High-angular momentum excitations in collinear antiferromagnet FePS$_3$

Jan Wyzula·Ivan Mohelsky·Diana Vaclavkova·Piotr Kapuscinski·Martin Veis·Clement Faugeras·Marek Potemski·Mike E. Zhitomirsky·Milan Orlita
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Abstract

We report on magneto-optical studies of the quasi-two-dimensional van der Waals antiferromagnet FePS$_3$. Our measurements reveal an excitation that closely resembles the antiferromagnetic resonance mode typical of easy-axis antiferromagnets, nevertheless, it displays an unusual, four-times larger Zeeman splitting in an applied magnetic field. We identify this excitation with an $|S_z|=4$ multipolar magnon -- a single-ion 4-magnon bound state -- that corresponds to a full reversal of a single magnetic moment of the Fe$^{2+}$ ion. We argue that condensation of multipolar magnons in large-spin materials with a strong magnetic anisotropy can produce new exotic states.

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Jan Wyzula, Ivan Mohelsky, Diana Vaclavkova, Piotr Kapuscinski, Martin Veis, Clement Faugeras, Marek Potemski, Mike E. Zhitomirsky, Milan Orlita. 2022-12-14. High-angular momentum excitations in collinear antiferromagnet FePS$_3$. https://doi.org/10.1021/acs.nanolett.2c04111

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