Invited Paper MI-ThM1
The X-ray View of Ultrafast Nano Magnetism

Thursday, November 3, 2011, 8:00 am, Room 105

Polarized soft x-rays have been used over the past 20 years to obtain fascinating new insights into nanoscale magnetism. The separation of spin and orbital magnetic moments, for instance, enabled detailed insights into the interplay of exchange and spin-orbit interactions at the atomic level. X-ray and photoelectron imaging techniques have revolutionized our understanding of magnetism of the ULTRA SMALL. In addition the now available polarized soft x-ray pulses with only few ps down to 100 fs duration allow us to observe the magnetic interactions at work in real time, i.e. they open the door to study ULTRA FAST magnetism. The ultimate goal of such studies is to understand how spins may be manipulated by ultrashort magnetic field, spin polarized current or light pulses. In this talk I will give an overview of achievements and the current status of probing magnetism of the ultra small and ultra fast using x-rays from synchrotrons [1-3] and more recently from x-ray free electron lasers.

[1] I. Radu, K. Vahaplar, C. Stamm, T. Kachel, N. Pontius, H. A. Durr, T. A. Ostler, J. Barker, R. F. L. Evans, R. W. Chantrell, A. Tsukamoto, A. Itoh, A. Kirilyuk, Th. Rasing, A. V. Kimel, Transient ferromagnetic-like state mediating ultrafast reversal of antiferromagnetically coupled spins, Nature 472, 205 (2011).

[2] M. Wietstruk, A. Melnikov, C. Stamm, T. Kachel, N. Pontius, M. Sultan, C. Gahl, M. Weinelt, H. A. Dürr, U. Bovensiepen, Hot-Electron-Driven Enhancement of Spin-Lattice Coupling in Gd and Tb 4f Ferromagnets Observed by Femtosecond X-Ray Magnetic Circular Dichriosm,, Phys. Rev. Lett. 106, 127401 (2011)

[3] C. Boeglin, E. Beaurepaire, V. Halté, V. Lopez-Flores, C. Stamm, N. Pontius, H. A. Dürr, J.- Y. Bigot, Distinguishing the ultrafast dynamics of spin and orbital moments in solids, Nature 465, 458 (2010).