Regensburg 2019 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 18: Poster Session: Topological Topics (joint session TT/MA)

TT 18.4: Poster

Montag, 1. April 2019, 15:00–18:30, Poster D

Bychkov-Rashba Spin-Orbit Coupling Effects in a Multi-Band Tight-Binding Model of Graphene — •Thorben Schmirander, Marta Prada, and Daniela Pfannkuche — I. Institut für theoretische Physik - Universität Hamburg, Hamburg, Deutschland

The description of Dirac electrons in the band structure of graphene is commonly performed using effective tight binding models [1]. These effective models use single-orbital Hamiltonians with modified hopping parameters in order to account for the influence of the higher energy orbitals in graphene. We go beyond such effective models by including d-orbitals in an atomistic tight-binding model. The inclusion of the Bychkov-Rashba spin-orbit coupling splits each of the two Dirac cones into four distinct ones [2]. When considering a finite graphene sample, edge states occur, which cross the band gap and connect the Dirac cones at the K and K’ point. These edge states are the key to the topological properties of graphene. The crossing of the edge states under the influence of Bychkov-Rashba spin-orbit coupling is examined by computing the winding number around each of the cones.
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