Dresden 2014 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

MA: Fachverband Magnetismus

MA 53: Spin Structures at Surfaces and in thin films II

MA 53.8: Vortrag

Freitag, 4. April 2014, 11:15–11:30, BEY 118

Superconducting scanning tunneling microscope tips as probes for absolute spin-polarization — •Matthias Eltschka¹, Berthold Jäck¹, Maximilian Assig¹, Markus Etzkorn¹, Christian R. Ast¹, and Klaus Kern^{1, 2} — ¹Max Planck Institute for Solid State Research, 70569 Stuttgart, Germany — ²Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland

Spin-polarized tunneling pioneered by Robert Meservey and Paul Tedrow has become an essential field of study and opened up the way for many applications [1]. We transfer the concept of superconducting detector electrodes commonly used in standard thin film sandwich junctions to scanning tunneling microscopy (STM) to locally probe absolute spin-polarization. We have studied superconducting vanadium STM tips on normal conducting samples in high magnetic fields at 10 mK. The superconducting properties of those tips are determined by the confinement due to the specific tip geometry. Superconducting STM tips have been employed as local probe for the absolute spin-polarization of Co nanoislands on Cu(111). Our results qualitatively agree with experiments carried out by SP-STM [2] but the absolute values of the measured spin-polarization allows for further analysis of the orbital wave functions involved in the tunneling process.

[1] P. M. Tedrow et al., Phys. Rev. Lett. 25, 1270 (1970); P. M. Tedrow and R. Meservey, Phys. Rev. Lett. 26, 192 (1971). [2] H. Oka et al., Science 327, 843 (2010).