Fig. 1: Dirac fermions on a triangular lattice.
From: Design and realization of topological Dirac fermions on a triangular lattice
a Sketch of the phase diagram as a function of SOC (λSOC) and ISB (λISB). The insets illustrate the band ordering of the Dirac fermions at the K and K′ points in the QSHI and trivial insulator phase. The coloring and the A/B labels correspond to the charge localization in b. b Triangular lattice (blue spheres) with substrate-induced ISB, as indicated by the C atoms (black spheres) in the first bilayer of the SiC(0001) substrate (Fig. 3a, c). The right half shows a honeycomb lattice (dotted gray lines) emerging from the charge localization of the chiral Dirac states, which peaks in the voids of the triangular lattice. c Interference mechanism between Bloch and orbital phases determining the charge localization, shown schematically for the example of a p− orbital at the K-point: the total phases (indicated by the rainbow color scheme) of neighboring sites contributing to the Bloch wave function interfere constructively at the B site. This promotes a high (bright) charge density centered around B, while destructive interference suppresses the charge localization in the A triangle.
