Low-energy spin-polarized electrons: their role in surface physics

Low-energy (∼100eV) electrons have been employed for more than half a century to investigate physical, chemical and electronic phenomena in condensed matter and surface physics. A particular role may be attributed to a purely quantum-mechanical property of the electron–its spin or intrinsic angular momentum. Since the 1970s the electron spin has been indispensable in determining the role of spin-dependent interactions, such as exchange interaction and spin-orbit coupling and their consequences. Most recently, the aspect of topology and its role in condensed matter systems has given a new drive to the investigation of the electron spin and spin textures in such materials. New results on time-dependent ultrafast phenomena may become available by the availability of new intense lasers and laser-driven sources.