Valley-Polarized Spin Splittings in Magnetized Pt Dichalcogenides

Using first-principles simulations, we show that pristine and Janus Pt dichalcogenides thin films (such as SePtTe) when deposited on the magnetic substrate α-MnSe develop giant proximity-induced magnetism and spin-valley polarization. Based on the analysis of symmetries of the system, we demonstrate that these effects are the result of an interplay of charge redistribution, broken inversion and time-reversal symmetries together with spin-orbit interactions. These mechanisms concur to the formation of unequal K and K' valleys in the conduction bands characterized by spin-splittings of the order of hundreds of meV. Remarkably, these properties are independent of the layer thickness and are present in both few-layers (semiconducting) and multilayered (metallic) heterostructures. Our results provide a platform for exploring novel spin-valley physics in low-dimensional materials, with promising applications in spintronic systems displaying spin-orbit torques that are resilient to disorder and temperature effects.