Laboratoire National des Champs Magnétiques Intenses, CNRS UPR3228, EMFL, Univ. Grenoble Alpes, Univ. Toulouse, Univ. Toulouse 3, INSA-T, Grenoble and Toulouse, F-38042, France.
Department of Physics, University of Fribourg, Chemin du Musée 3, CH-1700Fribourg, Switzerland.
Nano Lett. 2022 Dec 14;22(23):9741-9747. doi: 10.1021/acs.nanolett.2c04111. Epub 2022 Dec 2.
We report on magneto-optical studies of the quasi-two-dimensional van der Waals antiferromagnet FePS. 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 || = 4 multipolar magnon─a single-ion 4-magnon bound state─that corresponds to a full reversal of a single magnetic moment of the Fe ion. We argue that condensation of multipolar magnons in large-spin materials with a strong magnetic anisotropy can produce new exotic states.
我们报告了对范德瓦尔斯准二维反铁磁体 FePS 的磁光研究。我们的测量揭示了一种激发，它与易轴反铁磁体典型的反铁磁共振模式非常相似；然而，它在施加磁场中表现出不寻常的、大四倍的塞曼分裂。我们将这种激发与 || = 4 多极磁子——一个单离子 4 磁子束缚态——对应于 Fe 离子单个磁矩的完全反转联系起来。我们认为，在具有强磁各向异性的大自旋材料中，多极磁子的凝聚可以产生新的奇异态。
