Antrittsvortrag von Prof. Dr. Olena Fedchenko, Gisela and Wilfried Eckhardt Professorship for Experimental Physics in the area of Solid-State-Spectroscopy of Electronically Correlated Materials
Im Anschluss an die Einweihung des Gisela-Eckhardt-Platzes hält die neuberufene Professorin Dr. Olena Fedchenko Ihre Antrittsvorlesung. Ihre Professur an der Goethe-Universität hat Gisela Eckhardt durch eine testamentarische Stiftung an die Universität möglich gemacht.
The development of new materials is one of the key challenges in information technology. Electronic many-body effects, which give rise to fascinating phenomena such as superconductivity and spontaneous magnetic ordering, have inspired modern research to search for even more exotic effects to exploit for applications. Thus, understanding the correlation between unconventional superconductivity and spatial electronic modulations, such as magnetic, chiral, or charge density wave (CDW) orders, is one of the key challenges in current condensed matter research.
On the other hand, the understanding of magnetic, thermal, optical and electrical properties cannot be achieved without understanding the behaviour of the electrons within these materials and how they control the observable effects. The distribution of electronic states, the band structure, of a given material is unique, like a fingerprint. By tuning the band structure of materials, it is possible to dramatically change or even create new 'exotic' physical properties of advanced materials. Modulating band structures for the needs of modern electronics and materials science in general is therefore one of the main tasks of solid-state physics.
Angle-resolved photoelectron spectroscopy (ARPES) is one of the most powerful experimental techniques for probing the electronic states that determine most physical properties of materials. The technique is based on the photoelectric effect. By analysing the kinetic energy and angular distribution of photoelectrons emitted by light with photon energy above the work function, one gains direct access to the electronic band structure of a material.
The latest and most efficient electron spectrometer for ARPES is based on the time-of-flight (ToF) recording scheme. The time-of-flight momentum microscope (ToF-MM, is a new way of performing ARPES) allows the parallel detection of the 3D photoelectron distribution, i.e. the photo-emitted electron intensity as a function of the parallel momenta kx and ky and the final kinetic energy I(Ekin, kx, ky).
In my talk I will discuss recent developments and implementations of the ToF-MM technique for the study of electronically correlated materials. In particular, I will highlight its capabilities as a tool for structural analysis, electronic band structure studies and obtaining additional information with examples based on experimental studies of various modern materials.