Search for the origin of zero-energy modes in topological materials
Tomasz Dietl (International Centre for Interfacing Magnetism and Superconductivity with Topological Matter - MagTop, Institute of Physics, Polish Academy of Sciences, Warsaw)

As an introduction, I will show how relativistic effects in quantum materials science lead to inverted band structures and topological phases in a broad classes of semiconductors. As a specific example of the fascinating new physics, I will discuss point-contact spectroscopy of several topological materials, which reveals a transition to a low temperature phase that is characterized by zero-energy modes superimposed on an energy gap showing a Bardeen-Cooper-Schrieffer-type of criticality. An experimental(1) and theoretical(2) search for the origin of this striking behavior in diamagnetic, paramagnetic, and ferromagnetic topological crystalline insulators will be presented.
1. G.P. Mazur, K. Dybko, A. Szczerbakow, A. Kazakov, M. Zgirski, E. Łusakowska, S. Kret, J. Korczak, T. Story, M. Sawicki, T. Dietl "Experimental search for the origin of zero-energy modes in topological materials", arXiv:1709.04000v2 (2018).
2. W. Brzezicki, M.M. Wysokiński, and T. Hyart, "Topological properties of multilayers and surface steps in the SnTe material class", arXiv:1812.02168 (2018).