华中科技大学物理学院

报告摘要：

Chirality or handedness distinguishes an object from its mirror images, such as the spread thumb, index finger, and middle finger of the right and left hand. In mathematics, it is described by the outer product of three vectors that obey a right-hand vs. left-hand rule. The chirality of ground state magnetic textures defined by the vectors of magnetization, its gradient, and an electric field from broken inversion symmetry can be fixed by a strong relativistic spin–orbit interaction.

In this presentation, I focus on the chirality observed in the excited states of the magnetic order, dielectrics, and conductors that hold transverse spins when they are evanescent. Even without any relativistic effect, the transverse spin of the evanescent waves is locked to the momentum and the surface normal of their propagation plane. This chirality thereby acts as a generalized spin–orbit interaction, which leads to the discovery of various chiral interactions between magnetic, phononic, electronic, photonic, and plasmonic excitations in spintronics that mediate the excitation of quasiparticles into a single direction, leading to phenomena such as chiral spin and phonon pumping, chiral spin Seebeck, spin skin, magnonic trap, magnon Doppler, chiral magnon damping, and spin diode effects. Intriguing analogies with electric counterparts, which is named ``ferron”, in the ferroelectrics exist.

[1] T. Yu**, Z. Luo, and G. E. W Bauer, Chirality as generalized spin–orbit interaction in spintronics. Physics Reports 1009, 1-115 (2023).

[2] T. Yu**, J. Zou, B. Zeng, J. W. Rao, and K. Xia, Non-Hermitian topological Magnonics . Physics Reports 1062, 1-86 (2024).

[3] T. Yu**, X.-H. Zhou, G. E. W. Bauer, and I. V. Bobkova, Electromagnetic Proximity Effect: Superconducting Magnonics and Beyond, 1-108, arXiv:2506.18502.

报告人简介：

于涛，现任华中科技大学物理学院教授，博士生导师。2018年获中国科技大学博士学位。之后在荷兰代尔夫特理工大学、日本东北大学和德国马普物质结构和动力学研究所进行博士后研究工作。2021年加入华中科技大学，入选2021年国家高层次（海外）青年人才。长期专注于磁性、自旋电子学、轨道电子学、非常规超导电性及其交叉领域的理论工作。于涛课题组近四年来预言的多项理论工作，比如超导迈斯纳-磁子集体模式、超导约瑟夫森结中铁磁共振的巨频移、磁子热晶体管、铁电材料中铁振子双曲激发、磁性动力学激发表面声波等，获得国外、国内课题组的实验验证。

地点：M255会议室

联系人：刘永昌 特聘研究员 （8125 9247）

　　　　于国强 研究员 （8264 9215）