On Monday, October 27, 2025, at 12:00 c.t., Prof. Dr. Simon Moser will give his inaugural lecture as part of our Physics Colloquium.
Moser is Professor of Experimental Physics, in particular electronic properties of solids, at our faculty and conducts research into surface physics and the development of new quantum materials. His lecture is entitled "Transition Metal Oxides: A Story Told by Electrons".
Transition metal oxides are far more than mere combinations of oxygen and metallic elements-they are fertile playgrounds where electrons conspire to produce rich and often unexpected phenomena. When transition metals with their compact d ( or f) orbitals enter the picture, the interplay of charge, spin, and orbital degrees of freedom gives rise to strikingly diverse electronic behaviors, even in seemingly simple compounds.
In this colloquium, we will journey through the intricate electronic landscapes of several transition metal oxides. We begin with the prototypical dielectric anatase TiO₂, whose electronic state can be reversibly tuned from an insulator to a polaronic gas and further into a correlated metal. We then explore cupric oxide (CuO), a charge-transfer insulator harboring a frustrated antiferromagnetic ground state and the elusive Zhang-Rice singlet, a many-body state that is remarkably robust against disorder. Finally, we turn to the functional semimetal RuO₂-analleged "altermagnet" of current-whose non-symmorphic crystal structure gives rise to Dirac-like quasiparticles and flat-band surface states at the Fermi level.
Angle-resolved photoemission spectroscopy (ARPES) will serve as our guide throughout this exploration, revealing how electrons express the underlying stories of these materials through their band structures, symmetries, and interactions. Combined with state-of-the-art in situ oxide epitaxy, ARPES is now opening unprecedented opportunities to investigate and control the quantum properties of complex materials.
Abstract of the lecture by Prof. Moser
Prof. Dr. Julia Tjus will give an introduction to the lecture.
The faculty cordially invites all interested parties. The event will take place in lecture hall HZO 20.
All dates of the Physics Colloquium can be found here.
Photos: Prof. Simon Moser © RUB, Marquard & © Simon Moser