Aust-EU colloquium. Single magnetic adatoms on superconductors – probed by scanning tunneling and Josephson spectroscopy

  •  24 Jul 2024
     3:00 pm - 4:00 pm

Prof. Katharina J. Franke, Freie Universität Berlin

Zoom

Magnetic adatoms on superconductors induce bound states – known as Yu-Shiba-Rusinov (YSR) states – inside the superconducting energy gap of the underlying substrate. These states have been widely characterized by scanning tunneling microscopy/spectroscopy (STM/STS), leading to a fundamental understanding on how spin-carrying orbitals exchange couple to the substrate, how the YSR states hybridize and how they eventually form bands within the superconducting energy gap.

Additionally, magnetic adatoms on superconductors have been recognized as essential components in the construction of nanostructures featuring non-trivial topological characteristics.

Adding to this versatile platform, magnetic adatoms can be included into Josephson junctions formed by approaching the atom with a superconducting STM tip. Remarkably, the presence of YSR states induces diode-like behavior of the Josephson junction. This implies that the junction allows for dissipationless supercurrent flow in one direction, while the current in the other direction underlies dissipation.

The goal of Prof. Franke’s research is to understand fundamentals of electronic structure, molecular magnetism and electron transport at the single molecule scale. We employ low-temperature (1.2 K, 4.5 K) scanning tunneling microscopy (STM) and atomic force microscopy (AFM) in ultra-high vacuum for our investigations

Time Converter<