Layer-dependent spin-orbit torque switching of Néel vector in a van der Waals antiferromagnet.

Two-dimensional antiferromagnets that combine the dual advantages of van der Waals (vdW) and antiferromagnetic materials, provide an unprecedented platform to explore emergent spin-related phenomena. However, electrical manipulation of Néel vectors in vdW antiferromagnets -the cornerstone of antiferromagnetic spintronics- remains challenging. Here, we report layer-dependent electrical switching of the Néel vector in an A-type vdW antiferromagnet (Fe, Co)₃GaTe₂ (FCGT) with perpendicular magnetic anisotropy. The Néel vector of FCGT with odd-number vdW layers can be 180° reversed via spin-orbit torques. Furthermore, we achieve field-free switching in an all-vdW, all-antiferromagnet heterostructure of FCGT/CrSBr in which the noncollinear interfacial spin texture breaks the mirror symmetry. Our results establish layer-controlled spin symmetries and interfacial spin engineering as universal paradigms for manipulating antiferromagnetic order, paving the way for realising reliable and efficient vdW antiferromagnetic devices.