Fig. 1: The geometric and band structure of the monolayer and bilayer InSe.
From: Real-space observation of a time-reversal invariant topological state in twisted bilayer InSe
a The band structure of monolayer InSe. The contribution of Se-pz orbitals is indicated green dots. b The side and top view of spatial distribution of wave function of the valence band (VB) edge at k = Γ, as marked by a red rectangle in a. Blue and grey spheres represent In and Se atoms, respectively. Blue and yellow colors represent the phase of wave function. The isosurface value is 3.8 × 10 −7 e/bohr3. c Twisted bilayer InSe with a twist angle θ = 7.34°. The red and black circles highlight the AA stacking and AB stacking regions. d Energy bands of bilayer InSe with AB stacking and AA stacking configurations. The dash red lines indicate the height of valence band maximum (VBM), and the VBM difference of AA stacking and AB stacking is ΔE = 0.16 eV. The orange double arrows indicate splitting energy for the VBM states in the bilayer of AB stacking and AA stacking are ΔE = 0.59 eV and ΔE = 0.89 eV. e The spatial distribution of wave function of the valence bands at k = Γ, as marked by the red rectangles in d.
