Figure 4
From: Negative Quantum Capacitance Induced by Midgap States in Single-layer Graphene
(a) Total capacitance Ctg versus top gate voltage Vtg of the Ag-adsorbed single-layer graphene capacitor measured near the CNP at B = 0 T (red line), B = 5 T (green line), B = 7 T (blue line) and B = 8 T (orange line).The gray dashed line denotes the value of Cox = 0.65 μF/cm2. (b) Two-dimensional mapping of Ctg measured at T = 2 K as a function of top gate voltage Vtg and magnetic field B, where the regions in which the negative quantum capacitance (i.e. Ctg > Cox = 0.65 μF/cm2) emerges are colored in yellow and the numbers above the figure denote the LL positions.
