Axel Hoffmann博士
美国Argonne国家实验室
时间：5月20日（周三）10:00
地点：唐仲英楼A213室
摘要如下：
Magnetic interactions give rise to a surprising amount of complexity due to the fact that both static and dynamic magnetic properties are governed by competing short-range exchange interactions and long-range dipolar coupling. Even though the underlying dynamical equations are well established, the connection of magnetization dynamics to other degrees of freedom, such as charge and heat flow, make magnetism a mesoscale research problem that is still wide open for exploration. Synthesizing magnetic materials and heterostructures with tailored properties allows to take advantage of magnetic interactions spanning many-length scales, which can be probed with advanced spectroscopy and microscopy and modeled with micromagnetic simulations. In this talk, I will discuss two examples highlighting current opportunities in mesoscale magnetism. First, I will show how local Oersted magnetic fields from charge currents can manipulate the propagation of spin waves, enabling the guidance of spin-waves through curved waveguides and the switching of spin waves between multiple waveguides. Second, I will show how spin Hall effects can be used to electrically manipulate magnetostatically stabilized magnetic skyrmion structures. Using inhomogenous electric charge currents even allows the generation of skyrmions in a process that is remarkably similar to the droplet formation in surface-tension driven fluid flows.