报告题目：反铁磁拓扑结构成像与超快动力学

报 告 人：陈家浩 博士（国防科技大学理学院）

报告时间：2023年3月31日（周五）下午 16:00

报告地点：物理科学与技术学院老楼C-215

报告摘要：

The topological structures in various magnetic system are attracting broadening attention due to its potential of application in next generation memory devices. However, the ferromagnetic topological structures are disadvantage in offering smaller size to nanometers scale as well as much slower to be switched due to magnetic dipole interaction. Herein, I will introduce the procedure of identifying antiferromagnetic (AFM) structure with exotic topological properties, utilizing magnetic linear dichroism effect probed by soft-X ray from synchrotron.  A variety of AFM meron/bimeron structures are observed and generated by temperature cycling. Furthermore, the atomistic micromagnetic simulation suggests that the annihilation dynamics of these AFM structures are located within picosecond time scale, which provides a strong evidence in applying into ultrafast spintronic devices. Finally, I will give a brief introduction of our laboratory in investigating ultrafast dynamics from several quantum materials.

报告人简介：

陈家浩， 国防科技大学理学院物理系讲师，博士毕业于牛津大学凝聚态物理系，主要研究方向为太赫兹对自旋体系的超快调控。博士期间依托英国同步辐射Diamond与德国电子加速器DESY，开展基于软X射线多磁性圆/线二象色性（magnetic circular/linear dichroism，XMCD/XMLD) 成像技术研究，发现了多铁体、反铁磁的拓扑结构，并利用原子尺度的微磁学 方法模拟拓扑磁性的动力学演化过程，相关结果发表在Nature正刊，并选为候选封面文章[Nature, 590(7844), 74-79]。报告将围绕磁性体系的X射线二向色性成像原理与拓扑结构解析展开，介绍铁磁（多铁）和反铁磁两类体系的磁结构成像技术，并对超快时间尺度的铁性材料调控动力学做展望。