Extended Data Fig. 7: Device fabrication.
From: Cascade of electronic transitions in magic-angle twisted bilayer graphene
a, Schematic showing step-by-step device fabrication procedure for device A (device B is similar, but without PMMA). See Methods for details. b, In order to do STM measurements, MATBG must be ‘face up’. To achieve this, we transfer a MATBG/h-BN stack from its initial PVA handle to a secondary handle. Water injected between the two glass handles (each a standard 75 mm × 25 mm microscope glass slide) via a syringe dissolves the PVA. The glass slides are fixed on linear translation stages and are underneath an optical microscope. c, 500 nm × 500 nm STM topograph of device B showing a moiré pattern and physical corrugation in the underlying substrate (Vb = −400 mV, I = 100 pA). d, Zoomed-in image of the centre of the area in c. Each device has regions that are magic angle (which always show cascade features) and regions that are not magic angle (which do not show cascade features). Regions of a device that are magic angle are typically so over at least a square micrometre.
