Extended Data Fig. 6: Check for alignment to hBN.
From: Untying the insulating and superconducting orders in magic-angle graphene
a, Optical image of the monolayer graphene flake on SiO2 substrate used for fabrication of the MATBG heterostructure. White dashed arrows indicate preferable lattice directions (zig-zag or armchair). b, Optical image of the top hBN flake. c, Optical micrograph of the bottom hBN flake. d, Optical image of the final stack on SiO2 substrate. The black dashed arrow indicates the edge of the top hBN shown in b. The orange dashed arrow corresponds to the edge of the bottom hBN shown in panel c. Black (orange) numbers correspond to the angle between the white dashed arrow (graphene edge) and the top (bottom) hBN. We estimate the twist angle between the bottom hBN and MATBG to be about 7(±1.5)° or 23(±1.5)° and between the top hBN and MATBG to be about 25(±1.5)° or 5(±1.5)°. Furthermore, we do not find signatures of alignment to hBN in the magnetic field Shubnikov–de Haas oscillation data for any of the three devices (for example, Extended Data Fig. 7). Scale bars, 20 μm.
