Spin chain orientation and magneto-optical coupling in twisted NiPS3 homostructures

Abstract

Magnetic two-dimensional (2D) materials have garnered significant attention due to their unique electronic, magnetic, and optical properties and their potential applications in next-generation electronic and optoelectronic devices. However, the magneto-optical effects of oligolayer antiferromagnetic materials remain inadequately understood. Here, we investigate the magnetic properties of few-layer nickel phosphorus trisulfide (NiPS3) and its twisted heterostructures, emphasizing the observation of optical phenomena at low temperatures (1.65 K). By stacking few-layer NiPS3 to fabricate twisted homostructures, we probe their magnetic characteristics using photoluminescence (PL) spectroscopy. Our results reveal that sharp exciton peaks emerge at low temperatures and that the spin chain orientation in oligolayer NiPS3 can be discerned through the polarization dependence of exciton PL intensity. Notably, fewer-layered NiPS3 exhibits a significant magneto-optical effect under an applied magnetic field, allowing the modulation of the polarization angle of its exciton PL spectrum. Additionally, the polarization-dependent Raman spectrum of NiPS3 shows substantial changes under the influence of a magnetic field. These findings underscore the potential of few-layer NiPS3 for future magneto-optical device applications.