Quantum dynamics and heat transport in solids irradiated with femtosecond laser pulses

When a high energy laser pulse hits the solid it is possible that very short relaxation time is obtained (tau similar to 1fs). In that case the mean free path, lambda, of the hot electron is the older of the thermal de Broglie wavelength lambda(B). The temperature domain for which lambda is of the order of lambda(B) is defined as the quantum limit of the heat transport. In this paper the new quantum heat transport equation (QHT) is obtained, the relaxation time tau = h/mv(h)(2) and quantum diffusion coefficient D-T(Q) = h/m are calculated. The QHT is solved for the heat flux: 10(18) Wcm(-2) and the following initial temperature is obtained: T, similar to 100MeV for nanometer gold films.