A well-deserved honor: Dr. Lukas Fischer completes his PhD with summa cum laude

Lukas’s PhD thesis shows that microwave signals can manipulate magnetic domain walls in ultra-thin materials.

Title: “Magnetic Domain Wall Motion and Switching under Microwave Excitation”

Lukas’s thesis explores how microwave-frequency excitations influence the motion of magnetic domain walls and magnetic switching in ultrathin magnetic materials, which are key processes in spintronic devices. While magnetization dynamics at these frequencies are rarely investigated in this context, this work shows that they can have a strong impact on device behavior. It is demonstrated that domain walls can be excited by microwave magnetic fields or electrical currents, leading to unexpected effects such as self-driven motion without electrical pulses and sustained motion long after a current pulse ends. Crucially, these effects only emerge in the presence of weak external magnetic fields, whose symmetries determine the direction and nature of the domain-wall motion. Furthermore, a microwave excitation significantly enhances current-induced magnetic switching by facilitating domain wall motion, highlighting its central role in this process. Overall, Lukas’s work shows that microwave excitations provide new ways to manipulate magnetization, advancing both fundamental understanding and the technological potential of spintronics.