Figure 3

Dimensionless current density \(\overline{J }\) as a function of dimensionless voltage \(\overline{V }\) for the exact solution represented by (19) and the asymptotic solutions GMG and GCL, respectively, for dimensionless mobility \(\overline{\mu }=0.1\), dimensionless gap distance \(\overline{D }=250\), and dimensionless temperature \(\overline{T }=0.02\). Asymptotic solutions FN and RLD are excluded because they are outside the relevant range.