Protected Pseudohelical Edge States in Z2 -Trivial Proximitized Graphene
T. Frank, P. Högl, M. Gmitra, D. Kochan, J. Fabian
Physical Review Letters
Jaroslav Fabian and his group investigate topological properties of models that describe graphene on realistic substrates, which induce proximity spin-orbit coupling in graphene. Discussing how quantum anomalous Hall and quantum spin Hall effects arise in graphene, we also show how graphene with staggered intrinsic spin-orbit coupling, despite being topologically trivial, exhibits protected edge states. The spin character and robustness of the modes is best exhibited on a finite flake, which shows that the edge states have zero g-factor, carry a pure spin current in the crossection of the flake, and exhibit spin-flip reflectionless tunneling at the armchair edges.