  The recent discovery of two-dimensional magnetic insulators has generated a
great deal of excitement over their potential for nanoscale manipulation of
spin or magnetism. One intriguing use for these materials is to put them in
contact with graphene, with the goal of making graphene magnetic while
maintaining its unique electronic properties. Such a system could prove useful
in applications such as magnetic memories, or could serve as a host for exotic
states of matter. Proximity to a magnetic insulator will alter the spin
transport properties of graphene, and the strength of this interaction can be
probed with Hanle spin precession experiments. To aid in the analysis of such
experiments, in this work we derive an explicit expression for Hanle spin
precession in graphene interfaced with a ferromagnetic insulator whose
magnetization points perpendicular to the graphene plane. We find that this
interface results in a shifted and asymmetric Hanle response, and we discuss
how this behavior can be used to interpret measurements of spin transport in
these systems.
