Spin-polarized electron source and spin-polarized scanning tunneling microscope

A spin-polarized scanning tunneling microscope configured for investigating a domain structure of a magnetic sample, comprising:

• a probe disposed opposite to a surface of the magnetic sample separated therefrom by a vacuum gap, the probe including a one-dimensional nanostructure comprised of a compound semiconductor with local polarized gap states, the one-dimensional nanostructure having an end portion adjacent to the surface of the magnetic sample and acting as a probe tip of the probe, the end portion being configured for producing a spin-dependent tunneling current under an effect of selectably one of a magnetic field induction and a circularly polarized light beam excitation when a working voltage is applied onto the probe and the sample;
• a positioning driver configured for causing a relative movement between the probe and the magnetic sample to enable the probe tip to scan across the surface of the magnetic sample;
• a current detecting device configured for detecting the tunneling current generated between the probe tip and the magnetic sample;
• and
• a controller configured for receiving the tunneling current from the current detecting device and signaling a feed back signal to the positioning driver in order to regulate the relative movement between the probe and the magnetic sample.