Spin-polarized tunneling between Fe thin films and an optically pumped GaAs probe

It is well known that two electrodes separated by a potential barrier, of which electron densities of states are spin-polarized. yield spin-polarized electron tunneling[1]. Since scanning tunneling microscopy (STM) is based on the electron tunneling, if a sample and a probe have spin-polarized electron states, tunneling electrons detected by STM should be spin-polarized. To evaluate spin-polarization of the electrons allows the investigation of surface magnetism on nanometer scale.