Linnaeus Physics Colloquium: Topological contribution to the anomalous Hall effect at the interface

Lecturer: Carmine Autieri, International Research Centre MagTop, Institute of Physics, Polish Academy of Sciences, Warsaw, Poland
Title: Topological contribution to the anomalous Hall effect at the interface

Coffee and buns in Kalmar from 1.45 pm.

Abstract

Geometric phases in condensed matter play a central role in topological transport phenomena such as the quantum, spin and anomalous Hall effect (AHE). In contrast to the quantum Hall effect – which is characterized by a topological invariant and robust against perturbations – the AHE depends on the Berry curvature of occupied bands at the Fermi level and is therefore highly sensitive to subtle changes in the band structure. We demonstrate that the Berry curvature can be manipulated by interface engineering of the correlated itinerant ferromagnet and antiferromagnets.

Using theoretical calculations, we show that the tunability of the AHE at interfaces arises from the competition between two topologically non-trivial bands.

J. Groenendijk, C. Autieri et al. Berry phase engineering at oxide interfaces, https://arxiv.org/abs/1810.05619

Asa, C. Autieri et al. Anomalous Hall effect at the antiferromagnetic/non magnetic interface, https://arxiv.org/abs/1904.03541

Illustration

(a) Next-nearest-neighbor interorbital hopping.
(b) Dispersion of Ru t2g bands along kx = ky for a representative value of the magnetization.
(c) Berry curvature associated with topologically nontrivial Ru t2g bands close to the Fermi level (Chern numbers C = ±2.).
(d) Spin polarizations for the corresponding bands.