Figure 1

Energetics of a capacitive element. a The conduction bands (shown by the shaded region) under equilibrium, b In a macroscopic capacitor on application of a bias, the bands shift by an amount , where i = 1, 2 represent the left and right plates, respectively. c In a mesoscopic capacitor, the charge redistribution due to coulombic coupling causes the bulk to lose its charge neutrality. The chemical potential changes by an amount from its equilibrium value μ₀