Regensburg 2013 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MA: Fachverband Magnetismus
MA 19: Surface and Interface Magnetism I (jointly with O)
MA 19.4: Vortrag
Dienstag, 12. März 2013, 11:15–11:30, H33
Zeeman splitting in superconducting scanning tunneling microscopy tips — •Matthias Eltschka1, Berthold Jäck1, Maximilian Assig1, Markus Etzkorn1, Christian R. Ast1, and Klaus Kern1, 2 — 1Max Planck Institute for Solid State Research, 70569 Stuttgart, Germany — 2Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
Scanning tunneling microscopy (STM) is a powerful technique to investigate a manifold of physical and chemical phenomena at the atomic scale. For spin-dependent tunneling, superconducting STM tips are of particular interest due to the well-known spin-polarization of almost 100%, especially in combination with high energy resolution at ultra-low temperatures.
We present STM experiments on a V(100) sample in combination with several V-tips at milli-Kelvin temperatures. The applied magnetic fields exceed the critical magnetic field of bulk V, so that the sample is in the normal conducting state. Due to its reduced dimensions the tip apex remains superconducting in fields up to 10 Hc(bulk). Our evaluation of the experimental data is based on Maki’s model taking into account effects of orbital depairing and spin orbit coupling [1, 2]. Zeeman splitting of the superconducting quasi-particle densities of states is observed on several V-tips. Further, the quenching process of the superconducting gaps of the V-tips is investigated as function of magnetic fields.
[1] K. Maki, Prog. Theor. Phys. 32, 29 (1964)
[2] R. Meservey et al., Phys. Rev. B 11 4224 (1975)