Electronic correlations and a non-trivial bulk topology often determine the electronic properties of quantum phases of matter and leave distinct electronic fingerprints that can be detected with scanning tunneling microscopy (STM). In this talk, I will first describe a series of experiments that demonstrate how the combined influence of magnetism and superconductivity on the one-dimensional topological hinge state of bismuth gives rise to a Majorana zero mode (1). Second, I will discuss the unusual spectroscopic characteristics of the flat bands of magic angle twisted bilayer graphene in STM experiments and demonstrate the significant impact of local electronic correlations on the electronic properties of that material (2).
 

(1) B. Jäck et al., Science 364, 1255-1259 (2019).
(2) Y. Xie et al., Nature 572, 101–105 (2019).

 

Berthold Jaeck is a postdoctoral fellow of the Alexander-von-Humboldt foundation at Princeton University, USA where he works in the laboratory of Prof. Ali Yazdani. His current research interest is directed towards visualizing quantum phases of matter with a scanning tunneling microscope (STM). Prior joining Princeton University in 2016, Berthold has been working with Prof. Klaus Kern as a graduate school researcher at the Max-Planck-Institute for Solid State Research, Germany where he implemented novel imaging modalities with a STM. Berthold graduated with distinction from University of Würzburg, Germany with a diploma degree in applied physics in 2011, and holds a PhD degree in physics from Ecole Polytechnique Fédérale de Lausanne, Switzerland.