Figure 4 : Model DFT bands as a function of interfacial distance.

From: Creation of helical Dirac fermions by interfacing two gapped systems of ordinary fermions

Figure 4

(a,b) Bands at the artificially increased interfacial distance by 3 and 1 Å, respectively, showing the creation process of helical Dirac cone. (c) Spectral weight at the Dirac point resolved between the Bi BL and Bi2Se3 QL as a function of interfacial distance. (d) Interfacial charge transfer between Bi BL and Bi2Se3 QL at the equilibrium distance, showing the internal electrical field.