English

Orbital Hall effect and topology on a two-dimensional triangular lattice: from bulk to edge

Mesoscale and Nanoscale Physics 2023-12-05 v1 Disordered Systems and Neural Networks

Abstract

We investigate a generalized multi-orbital tight-binding model on a triangular lattice, a system prevalent in a wide range of two-dimensional materials, and particularly relevant for simulating transition metal dichalcogenide monolayers. We show that the interplay between spin-orbit coupling and different symmetry-breaking mechanisms leads to the emergence of four distinct topological phases [Eck, P., \textit{et al.}, Phys. Rev. B, 107 (11), 115130 (2023)]. Remarkably, this interplay also triggers the orbital Hall effect with distinguished characteristics. Furthermore, by employing the Landauer-B\"uttiker formula, we establish that in the orbital Hall insulating phase, the orbital angular momentum is carried by edge states present in nanoribbons with specific terminations. We also show that, as expected, they do not have topological protection against the disorder of the edge states belonging to a first-order topological insulator.

Keywords

Cite

@article{arxiv.2311.11715,
  title  = {Orbital Hall effect and topology on a two-dimensional triangular lattice: from bulk to edge},
  author = {Anderson L. R. Barbosa and Luis M. Canonico and Jose H. García and Tatiana G. Rappoport},
  journal= {arXiv preprint arXiv:2311.11715},
  year   = {2023}
}