Fig. 5: Chern number cascade and fractional quantum Hall gaps.
From: Direct probing of energy gaps and bandwidth in gate-tunable flat band graphene systems
a, b Longitudinal resistance Rxx and Hall resistance Rxy as a function of ntot and B. c Schematic of quantum oscillation of Fig. 5a. LLT is TMBG flat band LLs composed with DMG LLs Chern number offset. d Filling factor dependence of longitudinal resistance (blue dash line in Fig. 5a) and Hall resistance plateaus (red dash line in Fig. 5b). e zoomed Landau fan taken from yellow rectangular in Fig. 5a, b. The solid green line indicates ν = −11 integer quantum Hall state. The green dashed line denotes a fractional quantum Hall state of ν = −11 + 1/3. A, B are band edges of the fractional quantum Hall gap of νf = −6 + 1/3. The estimated gap △N = ∣μA − μB∣ = 0.56 ± 0.14 meV. f Evidence of a fractional quantum Hall state. The data of Rxx and Rxy are taken along the blue and red dash lines in Fig. 5e.
