SPIN-POLARIZED STM AND ITS FAMILY

Since STM was invented in 1982 it has proved to be the most powerful t ool for studying local electronic surface structure and has also led t o a number of related scanning tunneling microscopy methods to be deve loped. One of them is spin-polarized STM (SP-STM) which will image the local magnetic characteristics of the material surfaces. In 1992 we s ucceeded in detecting the tunneling current, which depends on the tip magnetization and the circular polarization of the light-pumping GaAs sample. These preliminary experiments and their results indicate the f easibility of SP-STM with a non-magnetic tip. Furthermore we are inves tigating exchange force microscopy which will play an important role i n the evaluation of insulating surface magnetism. This paper outlines both investigations together with recent progress in these areas. We a lso report on the experimental results of SP-STM in a vacuum.