Electron and phonon temperatures: Application to the thermal-shock propagation in nanowires

Abstract

Depending on the material properties of the system at hand, in some circumstances the application of a short pulse laser may initially bring a system into a highly non-equilibrium state wherein either the electron temperature may rise up while the lattice still remains cold, or conversely, because the heat capacity of electrons is usually different from that of lattice. In order to correctly describe the heat transport in those situations, therefore, one should properly split the non-equilibrium temperature into two different contributions: the electron temperature and the phonon temperature. By means of a recent two-temperature model (which fully agrees with the Maxwell-Cattaneo theory), in this paper we show that the values of those two temperatures may be always predictable during the thermal-shock propagation in nanowires, after having illustrated both that the employed theoretical model agrees with the basic tenets of continuum mechanics, and that it is mathematically well posed in the case of particular initial and boundary conditions. The main results of this paper could be used to deepen the concept of non-equilibrium temperature.