  We report on first-principle calculations on magnetic proximity effect in a
van der Waals heterostructure formed by a graphene monolayer induced by its
interaction with a two-dimensional (2D) ferromagnet (chromium tribromide,
CrBr3). We observe that the magnetic proximity effect arising from the
spin-dependent interlayer coupling depends sensitively on the interlayer
electronic configuration. The proximity effect results in spin polarization of
graphene orbital by up to 63.6 %, together with a miniband splitting band gap
of about 73.4 meV and 8% enhancement in magnetic moment (3.47${\mu}$B/cell) in
heterostructure. The position of the Fermi level in the Dirac cone is shown to
depend strongly on the graphene-CrBr3 interlayer separation of 3.77 Angstrom.
Consequently, we also show that a perpendicular electric field can be used to
control the miniband spin splitting and transmission spectrum. Also, the
interfacial polarization effect due to the existence of two different
constituents reinforces the conductivity via electrostatic screening in the
heterolayer. These findings point toward potential nanoscale devices where the
electric field driven magnetic proximity effect can lead to unique spin
controllability and possible engineering of spin gating.
