  We propose a spin valve that is based on van der Waals antiferromagnetism and
fully electrically controlled. The device is composed of two antiferromagnetic
terminals that allow for vertical bias control and a linked central scattering
potential region. The magnetoresistance varies significantly when the bias
orientations in two terminals are switched from parallel to antiparallel
because this switch induces a mismatch of the bands for the same spin
projection in different parts of the system. It is shown from density
functional calculations that bilayer graphene encapsulated by two atomic layers
of Cr$_2$Ge$_2$Te$_6$ provides a material platform to realize the
antiferromagnetism, which is robust against the required vertical electric
fields.
