title: Multiple quantum phases in graphene with enhanced spin-orbit coupling: from the quantum spin Hall regime to the spin Hall effect and a robust metallic state.
abstract: We report an intriguing transition from the quantum spin Hall phase to the spin Hall effect upon segregation of thallium adatoms adsorbed onto a graphene surface. Landauer-Büttiker and Kubo-Greenwood simulations are used to access both edge and bulk transport physics in disordered thallium-functionalized graphene systems of realistic sizes. Our findings not only quantify the detrimental effects of adatom clustering in the formation of the topological state, but also provide evidence for the emergence of spin accumulation at opposite sample edges driven by spin-dependent scattering induced by thallium islands, which eventually results in a minimum bulk conductivity ∼4e²/h, insensitive to localization effects.
authors.affiliation: Univ. Grenoble Alpes, IMEP-LAHC, F-38000 Grenoble, France and CNRS, IMEP-LAHC, F-38000 Grenoble, France.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Cresti
authors.affiliation: ICN2-Institut Catala de Nanociencia i Nanotecnologia, Campus UAB, 08193 Bellaterra (Barcelona), Spain and Department of Physics, Universitat Autónoma de Barcelona, Campus UAB, 08193 Bellaterra, Spain.
authors.forename: Dinh
authors.initials: D
authors.lastname: Van Tuan
authors.affiliation: ICN2-Institut Catala de Nanociencia i Nanotecnologia, Campus UAB, 08193 Bellaterra (Barcelona), Spain.
authors.forename: David
authors.initials: D
authors.lastname: Soriano
authors.affiliation: ICN2-Institut Catala de Nanociencia i Nanotecnologia, Campus UAB, 08193 Bellaterra (Barcelona), Spain.
authors.forename: Aron W
authors.initials: AW
authors.lastname: Cummings
authors.affiliation: ICN2-Institut Catala de Nanociencia i Nanotecnologia, Campus UAB, 08193 Bellaterra (Barcelona), Spain and ICREA-Institucio Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain.
authors.forename: Stephan
authors.initials: S
authors.lastname: Roche