Detection of the spin character of Fe(001) surface states by scanning   tunneling microscopy: A theoretical proposal
  We consider the magnetic structure on the Fe(001) surface and theoretically study the scanning tunneling spectroscopy using a spin-polarized tip (SP-STM). We show that minority-spin surface states induce a strong bias dependence of the tunneling differential conductance which largely depends on the orientation of the magnetization in the SP-STM tip relative to the easy magnetization axis in the Fe(001) surface. We propose to use this effect in order to determine the spin character of the Fe(001) surface states. This technique can be applied also to other magnetic surfaces in which surface states are observed. 
Athanasios N. Chantis, Darryl L. Smith, J. Fransson, A. V. Balatsky