Figure 6

Within the model of a locally elevated electronic temperature at the ballistic junction, the inferred electronic temperature from Eq. (5) vs bias voltage.

For data sets at 13 different conductances 3, 3.25, 3.5, 3.75, 4, 4.27, 4.5, 4.75, 5, 5.25, 5.51, 5.73, 6 G₀, the colors/markers, respectively, are: blue point, red point, green point, purple point, khaki point, blue star, red star, green star, purple star, khaki star, blue open square, red open square, green open square. (The apparent decrease seen in the shaded region is not physical and results from the failure at low bias of the approximation cosh(eV/2k_BT(V)) ≈ 1.) At high bias, inferred electronic temperatures increase monotonically with V, approximately independent of G. Error bars are dominated by the statistical uncertainty in the inferred Fano factor of the low-bias data. Dashed line is a fit to the simple model expression that assumes a local quasithermal electronic distribution, thermal transport by the electrons and a fraction α of the power IV dissipated locally in the junction, , with α = 0.02.