Laser-irradiation-induced temperature jump at interfaces: Evidence for the Kapitza effect in molecular-dynamics simulation

Using molecular-dynamics simulation, we find that the Kapitza effect—that is the thermal interface resistance responsible for the temperature jump at interfaces in heat diffusion phenomena—plays an important role in the case that a metal surface, which is adjacent to a transparent liquid dielectric, is heated by an ultrafast laser pulse. We observe a temperature jump with a width of three monolayers of the dielectric. Beyond the jump, the temperature profile in the dielectric is well described using analytical solutions of the appropriate heat conduction problem. This allows to determine the thermal interface resistance and the thermal diffusivity in the dielectric. The Kapitza effect is found to considerably delay the heat transfer to the dielectric.