Figure 2
From: Towards epitaxial graphene p-n junctions as electrically programmable quantum resistance standards
EG device characterization. (a) At B = 0.2 T and T = 1.7 K, the device’s longitudinal resistances (Rxx) in red and Hall resistances (Rxy) in blue are measured with respect to unipolar gate voltage. Rxx is measured for the upper and lower edge (UE and LE), shown as points and triangles, respectively, whereas the point and triangle symbols for Rxy represent just two different regions of the device. All legend numbers correspond to contact numbers from Fig. 1 (b) The carrier densities are measured (orange curves, dashed and dotted for the two different regions), the mobilities are calculated (green curve, with dashed and dotted appearances corresponding to the same two regions), and the capacitance models for both freestanding EG and EG undergoing charge transfer (due to adjacent neighboring layers) are plotted (pink dotted and dashed purple curves, respectively). The carrier densities and capacitance models are plotted on the left vertical axis, whereas the mobilities are plotted on the right vertical axis.
