Thickness-dependent spin Hall magnetoresistance in few-layer CrPS4/Pt heterostructures

Abstract

Van der Waals (vdW) antiferromagnets hold great promise for next-generation highdensity and high-speed spintronic devices due to their unique magnetic and electronic properties. In this work, we systematically investigate the thickness-dependent spin Hall magnetoresistance in ultrathin CrPS₄/Pt heterostructures. The transverse resistance exhibits a distinct spin-flop signature below the Néel temperature when the CrPS₄ thickness exceeds eight layers, whereas this feature gradually vanishes in thinner samples. Remarkably, an anomalous Hall signal emerges above the Néel temperature and persists even in devices with CrPS₄ as thin as three monolayers, remaining robust up to room temperature. Furthermore, angle-dependent longitudinal resistance measurements reveal that the magnitudes of both spin Hall magnetoresistance and anisotropic magnetoresistance are independent of the odd/even parity of the CrPS₄ layer number. Such behavior suggests that the interfacial spin-orbital coupled scattering from the orbital hybridization between CrPS₄ and Pt plays a critical role for magnetotransport phenomena. These findings provide important insights into the design and understanding of ultrathin van der Waals antiferromagnetic spintronic devices.