Fig. 1: Electronic structures of the twisted monolayer-bilayer graphene (tMBG) at 1.04°.
From: Imaging topological and correlated insulating states in twisted monolayer-bilayer graphene
a A schematic atomic structure of the tMBG. θ is the twisted angle between the top monolayer (red honeycomb structure) and the bottom bilayer graphene (blue and black structure). b Scanning tunneling microscopy (STM) topography of tMBG that showing the moiré patterns at bias voltage Vb = −1 V, tunneling current I = 50 pA. According to the collected differential conductance (dI/dV) spectra, different stacking configurations are assigned, and ABB, ABA, and ABC label the high-symmetry regimes according to the atomic registry. The color circles indicate the sites where we collect the spectra in (d) and (f) with the corresponding color code. The dashed line indicates the trace for the spatial evolution of flat band in Fig. 2d. c The calculated band structures for tMBG by the continuum model. Red shadow highlights the two flat bands. Solid and dashed lines correspond to the band of K and −K valley. d dI/dV spectra for the three high-symmetry regimes that are taken at full-filling state (gate voltage, Vg = +40 V) (Vb = −100 mV, I = 200 pA). e The density of states (DOS) that directly deduced from the band structure in (c), where Ud means the vertical electrostatic potential energy drop. VFB and CFB label the valence flat band and conduction flat band in (d) and (e). f dI/dV spectra for the three high-symmetry regimes that are taken at empty filling state (Vg = −40 V) (Vb = −100 mV, I = 200 pA).
