Transport Signatures of Spin-Orbit Coupling in Adatom-Decorated Graphene

Graphene's Dirac band structure and open geometry underlie exciting prospects for engineering new physics via impurity-induced spin-orbit coupling. As a tantalizing example, previous theory works predicted a robust quantum-spin-Hall phase in graphene covered with dilute heavy adatoms such as In, Tl, and Os, though experiments to date have not detected the required enhancement of spin-orbit coupling. Motivated by these experiments, this talk will explore the consequences of adatom-generated spin-orbit couplings on magneto-transport in graphene. We attack the problem using diagrammatic techniques and Landauer-Buttiker transport simulation informed by microscopics, and study various coverages, chemical potentials, and disorder types. We find that the induced spin-orbit couplings can contribute to magneto-conductance differently from conventional intrinsic and Rasbha spin-orbit couplings. Our results provide a possible rationale for the absence of spin-orbit signatures in recent experiments, and also highlight a roadmap for their discovery in future work.