Magnetic quantum structures

Abstract
A class of materials is discussed, where quantum effects have macroscopic consequences. These are magnetic multilayers with spacers down to a few atomic layers. It is shown how quantization perpendicular to the layers is connected with oscillatory magnetic coupling, which in turn is important for obtaining "giant" magnetoresistance. This effect is being applied towards the fabrication of magnetoresistive reading heads for magnetically-stored data. The capabilities of various synchrotron radiation techniques for studying such nanometer scale systems are discussed, e.g. angle-resolved, spinpolarized photoemission, magnetic circular dichroism and core level fluorescence. Possible extensions towards lateral superlattices and quantum wires are pointed out, where a stepped surface is acting as template.