  Magnetic fusion devices operate at regimes characterized by extremely high
temperatures and low densities, for which the charged particles motion is well
described by classical mechanics. This is not true, however, for solid-state
metallic objects: their density approaches $10^{28} \rm m^{-3}$, so that the
average interparticle distance is shorter than the de Broglie wavelength, which
characterizes the spread of the electron wave function. Under these conditions,
the conduction electrons behave as a true quantum plasma even at room
temperature. Here, we shall illustrate the impact of quantum phenomena on the
electron dynamics in metallic objects of nanometric size, particularly thin
metallic films excited by short laser pulses. Further, we will discuss more
recent results on regimes that involve spin and relativistic effects.
