  The impact of the intrinsic time-dependent fluctuations in the electrical
resistance at the graphene-metal interface or the contact noise, on the
performance of graphene field effect transistors, can be as adverse as the
contact resistance itself, but remains largely unexplored. Here we have
investigated the contact noise in graphene field effect transistors of varying
device geometry and contact configuration, with carrier mobility ranging from
5,000 to 80,000$~$cm$^{2}$V$^{-1}$s$^{-1}$. Our phenomenological model for
contact noise due to current crowding in purely two dimensional conductors,
confirms that the contacts dominate the measured resistance noise in all
graphene field effect transistors in the two-probe or invasive four probe
configurations, and surprisingly, also in nearly noninvasive four probe (Hall
bar) configuration in the high mobility devices. The microscopic origin of
contact noise is directly linked to the fluctuating electrostatic environment
of the metal-channel interface, which could be generic to two dimensional
material-based electronic devices.
