Heat Transport in Nanoscale Heterosystems: A Numerical and Analytical Study

Figure 6

Surface temperature evolution $?(0,t)$ for a 50?nm thick Bi-film (${\tilde{s}}_K=0.065$). The curves are obtained by convolving the results from the analytical solution with a rectangular function of 70?picoseconds width in order to account for the limited temporal resolution of the experiment (see text for detailed discussion). Compared to the fast decay at short times resulting from the model with an initially exponential temperature distribution, the surface of a homogeneously heated film cools down exponentially with a time-constant $t=5823$?picoseconds. For delays larger than 200?picoseconds, both models yield the same exponential decay.