  The exploration of spin configurations and magnetoresistance in van der Waals
magnetic semiconductors, particularly in the realm of thin-layer structures,
holds paramount significance for the development of two-dimensional spintronic
nanodevices. In this Letter, we conducted comprehensive magnetotransport
measurements on a few-layer CrSBr using a vertical tunneling device
configuration. Notably, our investigation revealed that tunneling
magnetoresistance possesses a distinctive capability to discern spin
configurations that would otherwise remain indistinguishable through
alternative techniques such as photoluminescence. We observed the existence of
energy-degenerate states exhibiting identical net magnetization and comparable
spin configurations, which could be differentiated based on their rectification
properties, reminiscent of a diode-like behavior at positive and negative bias
voltages. Specifically, in devices comprising 5-layer CrSBr, we observed an
intriguing positive magnetoresistive state when subjected to an in-plane
magnetic field along the $b$-axis. To gain a deeper understanding of the
underlying mechanisms, we developed a one-dimensional linear chain model that
successfully computed the magnetic state, thereby elucidating the underlying
spin configurations responsible for the observed transport phenomena. These
findings not only provide novel perspectives into the intricate spin textures
of two-dimensional CrSBr but also underscore the sensitivity of tunneling as a
probing technique for investigating the magnetic order in van der Waals
materials.
