  Two-dimensional (2D) magnetic materials offer unprecedented opportunities for
fundamental physics and applied research in spintronics and magnonics. Beyond
the pioneering studies on 2D CrI3 and Cr2Ge2Te6, this emerging field has
expanded to 2D antiferromagnets exhibiting different spin anisotropies and
textures. Of particular interest is the layered metamagnet CrSBr, a relatively
air-stable semiconductor formed by antiferromagnetically-coupled ferromagnetic
layers (Tc~150 K) that can be exfoliated down to the single-layer. It presents
a complex magnetic behavior with a dynamic magnetic crossover leading to a
low-temperature hidden order below T*~40 K. Here, we inspect the
magneto-transport properties of CrSBr vertical heterostructures in the 2D
limit. Our results demonstrate the marked low-dimensional character of the
ferromagnetic monolayer, with short-range correlations above Tc and an
Ising-type in-plane anisotropy, being the spins spontaneously aligned along the
easy-axis b below Tc. By applying moderate magnetic fields along a and c axes,
a spin reorientation occurs, leading to a magnetoresistance enhancement below
T*. In multilayers, a spin-valve behavior is observed, with negative
magnetoresistance strongly enhanced along the three directions below T*. These
results show that CrSBr monolayer/bilayer provides an ideal platform for
studying and controlling field-induced phenomena in two-dimensions, offering
new insights regarding 2D magnets and their integration into vertical
spintronic devices.
