Extended Data Fig. 2: Optical and scanning electron microscopy images of sample B.
From: Imaging work and dissipation in the quantum Hall state in graphene
a, Optical image showing the hBN/graphene/hBN heterostructure (light green), etched tranches exposing the SiO2/Si substrate (light blue), bottom plunger gates (light brown) and the metal contacts (dark). The dashed rectangle marks the region shown in Fig. 3, Extended Data Figs. 6, 7, 9, Supplementary Fig. 2 and with variable voltage Vpg applied to the plunger gates. The current is applied to the top contact and drained at the bottom contact and the corresponding voltages Vxx and V2p are measured in the scanning gate mode. b, Scanning electron micrograph of a twin sample of device B showing (from bright to dark) the metal contacts, four plunger gates, hBN/graphene/hBN, and the etched trenches.
