How surfaces Berry-curve Bloch-electrons

Date

Dec 8, 2022

Time

11:00 AM - 12:00 PM

Speaker

Prof. Dr. Jeroen van den Brink

Affiliation

IFW Dresden

Language

en

Main Topic

Materialien

Host

Dr. Silvia Seiro

Description

In recent years it has become clear that electronic Berry curvature (BC) is a key concept to understand and predict physical properties of crystalline materials. A wealth of interesting Hall-type responses in charge, spin and heat transport are caused by the BC associated to electronic bands inside a solid: anomalous Hall effects in magnetic materials, and various nonlinear Hall and Nernst effects in non-magnetic systems that lack inversion symmetry. However, for the largest class of known materials –-non-magnetic ones with inversion symmetry–- electronic BC is strictly zero. Here we show that precisely for these bulk BC-free materials, a finite BC can emerge at their surfaces and interfaces. This immediately activates certain surfaces in producing Hall-type transport responses. We demonstrate this by first principles calculations of the BC at bismuth, mercury-telluride (HgTe) and rhodium surfaces of various symmetries, revealing the presence of a surface Berry curvature dipole and associated quantum nonlinear Hall effects at a number of these. This opens up a plethora of materials to explore and harness the physical effects emerging from the electronic Berry curvature associated exclusively to their boundaries.

Links

• Seminars at the IFW

Last modified: Dec 8, 2022, 7:35:53 AM