On the possibility of resolving quantization axes of surface spins by means of a scanning tunneling microscope with a magnetic tip

Abstract

It is shown that a scanning tunneling microscope with a magnetic tip gives us, in principle, the possibility to determine the spin directions of surface magnetic ions with atomic resolution. The tip should not necessarily be a ferromagnet. For instance, the tip can just as well be an antiferromagnet with a magnetic structure of the spin density wave type such as observed in chromium. The advantage of an anti ferromagnetic tip is that it does not influence the studied surface through the magnetostatic field. An analogous consideration based on exchange interaction is valid for an atomic force microscope with a magnetic tip.