  Exchange bias is usually rationalized invoking spin pinning effects caused by
uncompensated antiferromagnetic interfaces. However, for compensated
antiferromagnets other extrinsic factors, such as interface roughness or spin
canting, have to be considered to produce a small uncompensation. As an
alternative, here we propose two (related) possible mechanisms, driven by the
intrinsic Dzyaloshinskii-Moriya interaction and ferroelectric polarization, for
the explanation of exchange bias effects in perovskites with compensated G-type
antiferromagnetism. One of the mechanisms is only active when a multiferroic
material is involved and it is controllable by electric fields.
