Tarik Pereira CYSNE
The orbital-Hall effect (OHE) refers to the creation of a transverse flow of orbital angular momentum (OAM) that is induced by a longitudinally applied electric field. This effect was predicted in p-doped silicon more than fifteen years ago. The theoretical development of the OHE was built in the context of three-dimensional (3D) metallic systems.
Only recently, the OHE acquired a consistent interest in the community of two-dimensional (2D) materials. The low dimensionality of the 2D materials and the geometry of its band structure allows the occurrence of orbital phenomena that are not present in most 3D systems. An example of these phenomena is the existence of orbital Hall insulating phases that can be indexed by an orbital Chern number [1]. The interest of the 2D-materials community by the OHE is also motivated, among other reasons, by the promise of the solution of old puzzles like the transport of OAM via valley Hall effect (VHE). In the conventional literature of 2D-materials, the transport of OAM was treated as a consequence of the VHE. This view successfully explained many experiments but it started to be questioned by an interpretation of the transport of OAM based on the OHE [1, 2]. In my talk, I will present some theoretical results that corroborate the idea of the OHE as a natural description of the transport of OAM in 2D materials. I will also extend the analysis to discuss possible experimental signatures of the OAM transport in 2D materials.
[2] S. Bhowal and G. Vignale, Phys. Rev. B 103, 195309 (2021)