Fig. 1: Non-interacting features of tM + N graphene.
From: Topological flat bands in a family of multilayer graphene moiré lattices
a Band structure calculations for t1 + 2 at its nominally optimal twist angle (θ = 1.13°) and interlayer potential (δ = 50 meV); defined as when the moiré conduction band (purple curve) has the narrowest dispersion while being simultaneously gapped (grey shaded regions) from both neighboring bands. Energy is measured with respect to the bottom of the moiré conduction band. The calculated valley Chern number, Cv, is shown for the moiré conduction band (see Methods for details). Similar calculations for b t1 + 3 (θ = 1. 3°, δ = 50 meV); c t2 + 3 (θ = 1.45°, δ = 90 meV); and d t2 + 4 (θ = 1.15°, δ = 50 meV). e Resistivity at zero magnetic field as a function of ν and D in a t1 + 2 device at θ = 1.13°. Gray color denotes experimental artifacts where negative resistance is observed, attributed to the effects of highly resistive states. Similar measurements for f t1 + 3 with θ = 1.29°; g t2 + 3 with θ = 1.50°; and h t2 + 4 with θ = 1.15°. Positive D is defined as pointing from the thin component to the thick component for all systems. Measurements taken at T = 1.7 K, except for e, where T = 0.3 K. i–l Layer–resolved LDOS calculated for the moiré conduction band, corresponding to the layer combinations and parameters in panels (a–d). The LDOS is normalized to the maximum value in each panel. Red and orange shadings delineate the M and N layers above and below the twisted interface. The interlayer potential used in the calculations corresponds to positive D in the experiment.
