Fig. 2: Charge separation.
From: Imaging topological and correlated insulating states in twisted monolayer-bilayer graphene
a–c The color contours of the dI/dV evolution as a function of doping level (Vg) and filling factor (\(\nu\)) for ABB, ABA, and ABC, respectively (Vb = −50 mV, I = 200 pA), here Vg0 = 3 V is the gate voltage to make the system charge neutral. The filling factors \({{{{{\rm{\nu }}}}}}\) that are deduced from the gate voltages. The yellow dashed lines in each panel indicate the Fermi level that we set as EF = 0 meV. VFB and CFB label the valence flat band and conduction flat band in (a). The black arrows in a (b) label the full filing at \(\nu =1\) (\(\nu =3\)). The dashed square in c highlights the correlation gap in the ABC region around Fermi level (EF). d Line profile of dI/dV spectra shows the flat-band bending at \(\nu =3\) along the dashed line in Fig. 1b. The arrows show the electron pools in the ABB region. Dash line labels the EF. e dI/dV spretra at \(\nu =2\) at the ABB, ABA, and ABC regions, wherein the flat bands show different filling status. Dash line labels the EF. f Extracting the local effective filling, R, of CFB from the dI/dV spectrum (blue curve) in e, where ALB (AUB) is the area under the spectrum of CFB below (above) EF. By following this method discussed in the main text, the extracted R = 0.51, corresponding to the scenario of two electrons filling the CFB in the ABC. The dashed line indicates the EF, red line services as the base line for removing the spectrum background.
