报告题目：Domain wall motion and spin wave

报 告 人：Xiang-Rong Wang，The Hong Kong University of Science and Technology

报告时间：11月29日（星期五）下午2:30

报告地点：物理系三楼报告厅

报告摘要：In this talk, I will discuss the interplay between magnetic domain wall (DW) motion and spin waves (SW). Both DW and SW are the fundamental excitations of magnetic systems. In a magnetic nanowire, we show that DW propagation accompanies normally spin wave emission on the one hand. On the other hand, a SW passing through a DW tends to drive the DW moving against the SW propagating direction. This interplay between DW and SW leads to very rich physics. 1). Magnon, quanta of SW, can efficiently mediate spin angular momentum transfer between SW and DW because magnons are spin-1 particles. 2) Magnonic spin-transfer torque can drive a DW to propagate at a high speed. 3) DW motion will generate SW, and, as a result, a static magnetic field can even drive a DW to propagate along a dissipationless nanowire through SW emission. 4) The widely believed Walker rigid-body propagation mode is not stable in a dissipated wire because of the SW emission, and DW propagation is locked into a soliton mode. Our studies imply that two DWs can interact with other through the SWs.