Possibility of revealing the spin-dependent surface potential of ferromagnets by detecting the spin-plitting of surface states or resonances by tunneling microscopy

Theoretical studies suggest that the spin-dependent part of the potential of electrons inside a ferromagnet does not vanish abruptly at the surface but has a long tail outside the surface.
This leads to Zeeman-like splitting of surface image states or resonance spectra. We suggest that this effect can be used for investigation of the spin-dependent surface potential by detecting the splitting with scanning tunneling spectroscopy.
Possibilities of such experiments on low-index Fe and Ni surfaces are discussed.