Landau levels, edge states, and strained magnetic waveguides in graphene monolayers with enhanced spin-orbit interaction

TL;DR

This paper analyzes the electronic properties of graphene monolayers with enhanced spin-orbit interactions under magnetic and strain-induced pseudo-magnetic fields, revealing new edge states, phase transitions, and robust waveguide modes.

Contribution

It provides analytical solutions for Landau levels with arbitrary SOI, studies edge states and phase transitions, and explores strain-induced waveguides with spin textures in graphene.

Findings

Analytical Landau level eigenstates with enhanced SOI

Identification of a quantum phase transition with spin-filtered edge states

Proposal of strain-induced waveguides with chiral snake orbits

Abstract

The electronic properties of a graphene monolayer in a magnetic and a strain-induced pseudo-magnetic field are studied in the presence of spin-orbit interactions (SOI) that are artificially enhanced, e.g., by suitable adatom deposition. For the homogeneous case, we provide analytical results for the Landau level eigenstates for arbitrary intrinsic and Rashba SOI, including also the Zeeman field. The edge states in a semi-infinite geometry are studied in the absence of the Rashba term. For a critical value of the magnetic field, we find a quantum phase transition separating two phases with spin-filtered helical edge states at the Dirac point. These phases have opposite spin current direction. We also discuss strained magnetic waveguides with inhomogeneous field profiles that allow for chiral snake orbits. Such waveguides are practically immune to disorder-induced backscattering, and the SOI provides non-trivial spin texture to these modes.