  An antiferromagnetic metal with two-dimensional triangular network offers a
unique playground of intriguing magneto-transport properties and
functionalities stemming from interplay between conducting electrons and
intricate magnetic phases. A NiAs-type CrSe is one of the candidates owing to
alternate stackings of Cr and Se triangular atomic networks in its crystal
structure. While fabrication of CrSe thin films is indispensable to develop
functional devices, studies on its thin-film properties have been limited to
date due to the lack of metallic samples. Here, we report on realization of
metallic conductivities of CrSe thin films, which allows to investigate their
intrinsic magneto-transport properties. The metallic sample exhibits
co-occurrence of a weak ferromagnetism with perpendicular magnetic anisotropy
and the antiferromagnetic behavior, indicating the presence of non-coplanar
spin structures. In addition, control of polarity and tilting angle of the
non-coplanar spin structure is accomplished by a sign of cooling magnetic
fields. The observed non-coplanar spin structure, which can be a source of
emergent magnetic field acting on the conducting electrons, highlights a high
potential of the triangular lattice antiferromagnet and provide unique platform
for functional thin-film devices composed of NiAs-type derivative Cr
chalcogenides and pnictides.
