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TT: Fachverband Tiefe Temperaturen
TT 34: Superconductivity: Tunneling and Josephson Junctions
TT 34.10: Vortrag
Dienstag, 13. März 2018, 12:15–12:30, H 2053
Charge Transfer across a Scanning Tunneling Microscope Junction in Presence of a Macroscopic Impedance — •Simon Dambach1, Christian R. Ast2, Björn Kubala1, Jacob Senkpiel2, Markus Etzkorn2, and Joachim Ankerhold1 — 1Institute for Complex Quantum Systems, Ulm University, Ulm, Germany — 2MPI for Solid State Research, Stuttgart, Germany
When it comes to probing electronic structure on an atomic scale, scanning tunneling microscopy has evolved into one of the most powerful and versatile experimental techniques over the last decades. Recent progress in pushing the energy resolution to the low energy scales that are necessary for resolving extremely sharp spectral features (e.g., superconducting gaps, Yu-Shiba-Rusinov states, or Kondo peaks) has led to the development of an ultra-precise scanning tunneling microscope operating at 15 mK [1]. At these low temperatures, the device is operated at the quantum limit, i.e., the granularity of the current becomes non-negligible. The ultimate resolution is limited here by the electromagnetic interaction of the tunneling charge quantum with the surrounding and the capacitative noise of the junction.
In this talk, we provide a theoretical study of the electrical current across a scanning tunneling microscope junction in presence of an environmental macroscopic impedance. On the basis of P(E) theory, which describes the probability for a loss or gain in energy during a tunneling process, we obtain corrections to the I(V) characteristics which reproduce data of current measurements with high accuracy.
[1] C. R. Ast et al., Nat. Commun. 7, 13009 (2016)