  Our world is composed of various materials with different structures, where
spin structures have been playing a pivotal role in spintronic devices of the
contemporary information technology. Apart from conventional collinear spin
materials such as collinear ferromagnets and collinear antiferromagnetically
coupled materials, noncollinear spintronic materials have emerged as hot spots
of research attention owing to exotic physical phenomena. In this Review, we
firstly introduce two types noncollinear spin structures, i.e., the chiral spin
structure that yields real-space Berry phases and the coplanar noncollinear
spin structure that could generate momentum-space Berry phases, and then move
to relevant novel physical phenomena including topological Hall effect,
anomalous Hall effect, multiferroic, Weyl fermions, spin-polarized current, and
spin Hall effect without spin-orbit coupling in these noncollinear spin
systems. Afterwards, we summarize and elaborate the electric-field control of
the noncollinear spin structure and related physical effects, which could
enable ultralow power spintronic devices in future. In the final outlook part,
we emphasize the importance and possible routes for experimentally detecting
the intriguing theoretically predicted spin-polarized current, verifying the
spin Hall effect in the absence of spin-orbit coupling and exploring the
anisotropic magnetoresistance and domain-wall-related magnetoresistance effects
for noncollinear antiferromagnetic materials.
