  We report the magnetic response of Co/Pt multilayers to picosecond electrical
heating. Using photoconductive Auston switches, we generate electrical pulses
with 5.5 picosecond duration and hundreds of pico-Joules to pass through Co/Pt
multilayers. The electrical pulse heats the electrons in the Co/Pt multilayers
and causes an ultrafast reduction in the magnetic moment. A comparison between
optical and electrically induced demagnetization of the Co/Pt multilayers
reveals significantly different dynamics for optical vs. electrical heating. We
attribute the disparate dynamics to the dependence of the electron-phonon
interaction on the average energy and total number of initially excited
electrons.
