Dresden 2006 – scientific programme

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O: Oberflächenphysik

O 33: Scanning probe techniques III

O 33.2: Talk

Thursday, March 30, 2006, 11:30–11:45, PHY C213

Computing scanning tunneling spectroscopy by the layer-KKR real-space method — •Kamal K. Saha, Jürgen Henk, Arthur Ernst, and Patrick Bruno — Max-Planck-Institut für Mikrostrukturphysik, Halle/Saale, Germany

Often, the computation of scanning tunneling spectroscopy (STS) relies on severe approximations. For example in the Tersoff-Hamann model, the electronic structure of the STM tip is taken into account rather imprecisely. Or in a supercell approach, the periodicity may lead to artifacts.

In this contribution, a new approach to compute STS from first principles is proposed. Applying a self-consistent real-space multiple-scattering theory (here: spin-polarized relativistic layer-KKR) for the Green function of the tunnel junction, the abovementioned shortcomings can be avoided. The conductance is obtained within the Landauer-Büttiker theory.

After introducing key issues of the proposed approach, its application to the Co(0001) surface will be discussed, with a focus on the tunnel magnetoresistance due to spin-polarized surface states.