Fig. 3: High quality of LATTG devices.

a Schematic structure of LATTG devices, graphene layers (b, m, and t labels indicate bottom, middle, and top layers, respectively) are twisted by large angles \({\theta }_{12}\) (the angle between the bottom and the middle layers) and \({\theta }_{23}\) (the angle between the middle and the top layers). See “Methods” for further information. Optical images show two measured LATTG Hall bar devices A and B, scale bar is 5 μm. b Longitudinal resistance at B = 0 T as a function of charge density \({n}_{{\mbox{tot}}}\) and displacement field D measured in device A. Coloured lines indicate conditions of CNP for top, middle, and bottom layers with black, red, and yellow correspondingly. Inset band structures illustrate the position of CNPs of each layer. c Longitudinal resistance at B = 50 mT as a function of \({n}_{{\mbox{tot}}}\) and D measured in device A. Coloured dashed lines show the calculated CNP positions for all three layers based on the electrostatic model described in the Supplementary Note 1. We therefore label the nearest Landau levels as ±1, ±2, with the sign reflecting the charge carrier type in each layer. d–g Magnetoresistance measurements for devices A and B. d, f Measured for fixed D = −0.5 V/nm and D = 0.5 V/nm correspondingly as a function of \({n}_{{\mbox{tot}}}\), coloured arrows show positions of CNPs. e, g Longitudinal resistance measured for fixed \({n}_{{\mbox{tot}}}\) as a function of D with removed background (see Supplementary Fig. 10 for more details). Onset of Landau quantisation become resolvable already at \({B}^{*}=5-7\) mT in (e) and at \({B}^{*}=5-6\) mT in (g). Measurements were done at 2 K for all panels.