主 讲 人 ：孙达力    副教授

活动时间：10月14日10时00分    

地　　点：理科2号楼 A408

讲座内容：

Researchers have shown that hybridorganic-inorganic perovskites(ororganometal trihalide perovskites)are not only aimed to be used in solar cell applications but also pursue a vastvariety of fundamental research directions. One of the growing topics is the understandingof the photo-physics and the spin-related properties in hybrid perovskites since they play a major role in the processes of carrier photogeneration and carriertransport, which are the corner stone’s of photovoltaic applications, as wellas in other optoelectronic applications. In this talk, we will discuss the spin-optoelectronic andmagnetic properties of these solution-processed hybrid materials and theirfundamental spin-dependent physical behavior: (i) We will talk about the observation of spintronic-Terahertz (THz) radiation in layered Pb-based hybridperovskites interfaced with a ferromagnetic metal, produced by ultrafast spincurrent under femtosecond laser excitation. Due to the presence of the pronounced Rashba splitting state in Pb-based hybrid perovskites, the generated THz radiation exhibits an asymmetric intensity toward forward and backward emission direction whose directionality can be mutually controlled by the direction of the applied magnetic field and linear polarization of the laser pulse. (ii) We will show that the Dzyaloshinskii–Moriya-Interaction (DMI), a chiral antisymmetricinter action that occurs in magnetic systems with low symmetry, can be presentedin layered magnetic hybrid perovskites of which the metal site, Pb is replacedby Cu. We show that layered Cu-based hybrid perovskite antiferromagnets with aninterlayer DMI will lead to a strong intrinsic magnon-magnon coupling strengthup to 0.24 GHz, which is four times greater than the dissipation rates of the acoustic/opticalmagnonic modes. Our work shows that the DMI in these hybrid antiferromagnetsholds promise for leveraging magnon-magnon coupling by harnessing symmetrybreaking in a highly tunable, solution-processable layered magnetic platform.

主讲人介绍：

孙达力博士2009年毕业于北京中科院物理所磁学M04组（导师：成昭华 研究员）。2009年至2011年期间在美国国家橡树岭实验室从事博士后研究，并在沈健教授（现复旦大学物理系）指导下进行有机物自旋阀的研究工作。2012年至2014年期间在美国犹他大学物理天文系继续博士后研究，在Z. Valy Vardeny 教授指导下从事聚合物和小分子自旋特性的研究。2015年至2016年期间在犹他大学担任研究助理教授主导有机无机杂化钙钛矿材料的自旋特性的研究。2017年至今在美国北卡罗纳州州立大学物理系任教担任终身副教授。他的主要研究兴趣包括有机物半导体和有机无机杂化钙钛矿材料的自旋电子学，自旋轨道耦合，Rashba 效应，以及新型复合材料内部的自旋电荷相互转换和自旋器件的研究，还包括有机无机金属材料的界面自旋特性等。目前在包括Nature Materials (3), Nature Physics (2), NatureCommunications (6), Science Advances (1) 等学术期刊发表论文71篇。