QUANTUM-WELL AND QUANTUM-WIRE STATES AT METAL-SURFACES

Novel effects in magnetic Multilayer structures, such as oscillatory m agnetic coupling and ''giant'' magnetoresistance, have created new mat erials that allow for an order of magnitude higher sensitivity in the detection of magnetically-recorded dat a. Determination of their elect ronic and magnetic structures with angle-resolved photoemission and in verse photoemission reveals quantized states in the noble metal spacer layers which are connected with oscillatory magnetic coupling and hav e implications on magnetoresistance. These states can be understood by a simple interferometer model, including the spin-dependent interface reflectivity that polarizes them and transmits the magnetic coupling through the noble metal spacer. Current efforts are discussed, which a im towards fabricating quantum wires and lateral superlattices on meta ls by decorating steps at vicinal surfaces. STM work on the growth mod e of such structures is presented, which uses spectroscopic contrast t o distinguish different metals. Specific electronic states at decorate d step edges are found with inverse photoemission.