Großes Physikalisches Kolloquium | June 09, 16:30
Ultrafast magnetism – terra incognita beyond the conventional approximation
While magnetism is essentially the strongest quantum mechanical phenomenon, modern description of magnetization dynamics and magnetization reversal relies on thermodynamics and the corresponding approximations. I will show that ultrashort (sub-100 ps) stimuli push magnetic media into a strongly non-equilibrium state, where the conventional description of magnetic phenomena in terms of equilibrium thermodynamics is no longer valid and the experimentally observed ultrafast magnetization dynamics challenge the current theories of magnetism. For instance, while according
to thermodynamics and simply intuition, heat can only destroy magnetization, we will demonstrate that ultrafast (sub-100 ps) heat pulse can cause magnetization reversal without any magnetic fields. I will speculate on the future of ultrafast magnetism — both as a platform for technological innovation and as a frontier in fundamental research. In particular, I will discuss the exciting opportunities emerging from studies of antiferromagnets - the largest, least explored, and arguably most intriguing class of magnetic materials, discovered only in the 20th century.
Institute for Molecules and Materials, Radboud Universiteit, Nijmegen, The Netherlands
H3
Contact: Paul van Loosdrecht