Topological Magnon Matter and Transverse Magnon Transport

量子物理学・ナノサイエンス第35回特別セミナー

概要

Magnons are carriers of spin and heat, and can show transverse transport phenomena, one example being the thermal magnon Hall effect [1]. As in the case of electrons, this Hall-type transport is related to the topologically nontrivial magnon spectrum, that is, to k-space Berry curvature [2,3]. In this talk, I give an introduction to topological magnon matter. In particular, I present the magnonic pendants to electronic topological insulators [4], Weyl semimetals [5,6], and nodal-line semimetals [7].Thereafter, I introduce a method based on atomistic spin dynamics simulations for the calculation of magnon transport tensors, describing the response of a classical spin cluster to a magnetic-field gradient and a temperature gradient. It is applied to both a ferromagnetic topological magnon insulator [8] and a skyrmion crystal phase induced by frustration [9]. Magnon Hall angles as large as 60% are predicted.

References

• [1] Y. Onose et al., Science 329, 297 (2010)
• [2] H. Katsura et al., Phys. Rev. Lett. 104, 066403 (2010)
• [3] R. Matsumoto et al., Phys. Rev. Lett. 106, 197202 (2011)
• [4] L. Zhang et al., Phys. Rev. B 87, 144101 (2013)
• [5] F.-Y. Li et al., Nature Commun. 7, 12691 (2016)
• [6] A. Mook et al., Phys. Rev. Lett. 177, 157204 (2016)
• [7] A. Mook et al., Phys. Rev. B, accepted (2016/17)
• [8] A. Mook et al., Phys. Rev. B 94, 174444 (2016)
• [9] A. Mook et al., Phys. Rev. B (R), accepted (2016/17)

• 量子物理学・ナノサイエンス第35回特別セミナー

• ナノサイエンス・量子物理学国際研究センター 主催
• 東京工業大学理学院・物理学系、「ナノサイエンスを拓く量子物理学拠点」共催