The Dirac semimetal RuO2: From topology to functionality

Datum

06.09.2019

Zeit

10:30 - 11:30

Sprecher

Dr. Simon Moser

Zugehörigkeit

Julius-Maximilians-Universität Würzburg

Sprache

en

Hauptthema

Materialien

Host

Beschreibung

The functional Dirac semi-metal RuO2 is a binary model oxide whose topological properties are at the heart of its industrially exploited functionality. As a consequence of its non-symmorphic rutile crystal structure, RuO2 expresses a complex Fermi surface composed of Dirac nodal lines (DNL) that serve as an anchor for a van Hove singularity shaped flat band surface state (FBSS). This FBSS is believed to play a crucial role in a variety of benchmark industrial catalytic processes that exploit the unique catalytic efficiency of the RuO2 surface. Further, the pronounced nesting of DNLs are prone to Fermi surface instabilities, a postulated driving force of the recently discovered room temperature collinear antiferromagnetism (AFM) in RuO2. Surprisingly, the interplay of collinear AFM order, non-symmorphic crystal structure and significant spin-orbit coupling of the Ru 4d manifold produces a novel type of anomalous Hall effect (AHE) – the crystal Hall effect (CHE). This CHE is attributed to a particularly strong Berry curvature effect, which persists even in the absence of a net magnetization and makes RuO2 a promising material candidate for a variety of transport applications. RuO2 thus presents a unique opportunity to study the fundamental topological properties of a non-toxic binary model oxide, and their direct impact on its genuine industrial utility.

Links

• Seminars at the IFW

Letztmalig verändert: 06.09.2019, 00:09:45