Public Physic Colloquium in the Winter Terms 2010/2011 in Münster
Place:    Germany, 48149 Münster, Wilhelm-Klemm-Str. 10, IG I, HS 2
Time:     Thursday, 05.05.2011  16:00 h c.t.
Colloquium Coffee at 15:45 h  at the Lecture Hall

Multichannel Spin Polarimetry and Hard X-ray Photoemission: Breaking old Paradigms

Prof. Dr. G. Schönhense, Institut für Physik, Universität Mainz

Spin-polarization measurements of free electrons remain challenging since their first realization by Mott. As Heisenberg’s uncertainty principle forbids the Stern-Gerlach experiment for free electrons the determination of spin polarization relies on spin-orbit or exchange scattering, reducing the efficiency by orders of magnitude. In turn, important research fields like single shot experiments with XUV laser pulses or non-repetitive phenomena in ferromagnets are inaccessible with state-of-the-art spin detectors. Our novel approach of two-dimensional multichannel spin-detection overcomes this drawback with an efficiency increased by 4 orders of magnitude. With the advent of high-resolution, high-brilliance beamlines for hard X-rays in the 6-10 keV range, photoemission of deeply buried layers and inner interfaces became possible. The mean free path of such fast photoelectrons is of the order of 10 nm, so that probing depths above 20 nm can be reached. When combined with magnetic dichroism and/or spin analysis, this bulk sensitivity provides a powerful tool for the study of magnetic multilayer systems.

Invited from: Prof. Dr. C. Weinheimer

By Order of the Professors of the Department of Physics