Possibility of revealing the spin-dependent surface potential of ferromagnets by detecting the spin-splitting 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. (C) 1998 Elsevier Science B.V. All rights reserved.