Fig. 4: Density functional theory (DFT) calculation of a single 1T′-2H interface.
From: Room-temperature quantum spin Hall phase in laser-patterned few-layer 1T′- MoS2
Density of states as function of wave vector parallel to the 1T′-2H interface projected in the vicinity of the interface (schematically shown in the inset). The inverted bulk bands and the bulk gap opened by spin-orbit coupling can be seen near Gamma. The brightness reflects the weight of the states near the interface. The thin lines continuously connecting the conduction band with the valence band correspond to the protected helical states located at the interface. The protection is evident from the fact that the interface band crosses three times the Fermi energy (set to zero) or, in general, an odd number of times if small deviations of the Fermi energy are allowed within the gap.
