Programme

Introduction to Rashba physics, its origin and its relevance in the context of spintronics applications. Tight-binding approximations to describe Rashba interactions in t2g-systems and introduction to semiclassical approximations to describe transport. Discussion of Rashba splitting, trivial/nontrivial anticrossings and ensuing spin band-textures.

Basics of the Edelstein effect, and what distinguishes it from other effects, such as the spin Hall effect. Discussion of spin and orbital Edelstein effects, and how can they be evaluated using semiclassical approximations. Edelstein effect applied to t2g systems. Specific contributions to orbital/spin Edelstein effects coming from the features of the band structure, paying particular attention to contributions coming from topologically trivial/nontrivial anticrossings, and their relevance for the spin-charge conversion problem.

Short introduction to the concept of Berry connection, Berry phase and Berry curvature, and their link to topological quantum matter. How Berry curvature generates an anomalous velocity and explain the analogy of Berry curvature as a source of “magnetic field”. Discussion of the role of symmetry, dimensionality and the occurrence of Berry curvature. Why Berry curvature is related to the anomalous Hall effect. These concepts will be applied to electronic structures in ferromagnetic systems with spin-orbit coupling, focusing first on SrRuO3 as a materials case where the effects of Berry curvatures can be analyzed. The concept of Weyl node will be introduced. Generality of these concepts to other ferromagnetic systems, considering the role of dimensionality and symmetry.

The discussion will focus on the case of low-dimensional systems, in particular on oxides with (t2g) orbital close to the Fermi level. Discussion of oxide interfaces, as a platform for the design of sources of Berry curvature without Weyl cones. Differences between the previous case (Berry curvatures generated by Weyl cones) and the present (without Weyl cones). Berry curvatures with spin and orbital sources. Why it is important to design spin and orbital sources? What is the generality of these concepts? Are other materials relevant beyond oxide interfaces (e.g. antiferromagnets or superconductors)?