Layered Antiferromagnetism Induces Large Negative Magnetoresistance in the van der Waals Semiconductor CrSBr

The recent discovery of magnetism within the family of exfoliatable van der Waals
(vdW) compounds has attracted considerable interest in these materials for both
fundamental research and technological applications. However current vdW magnets
are limited by their extreme sensitivity to air, low ordering temperatures, and poor
charge transport properties. Here we report the magnetic and electronic properties of
CrSBr, an air-stable vdW antiferromagnetic semiconductor that readily cleaves
perpendicular to the stacking axis. Below its Néel temperature, TN=132±1 K, CrSBr
adopts an A-type antiferromagnetic structure with each individual layer
ferromagnetically ordered internally and the layers coupled antiferromagnetically along
the stacking direction. Scanning tunneling spectroscopy and photoluminescence (PL)
reveal that the electronic gap is ΔE=1.5±0.2 eV with a corresponding PL peak centered
at 1.25±0.07 eV. Using magnetotransport measurements, we demonstrate strong
coupling between magnetic order and transport properties in CrSBr, leading to a large
negative magnetoresistance response that is unique amongst vdW materials. These
findings establish CrSBr as a promising material platform for increasing the applicability
of vdW magnets to the field of spin-based electronics.