Magnetic-Proximity-Induced Efficient Charge-to-Spin Conversion in Large-Area PtSe₂/Ni₈₀Fe₂₀ Heterostructures

As a topological Dirac semimetal with controllable spin-orbit coupling and conductivity, PtSe₂, a transition-metal dichalcogenide, is a promising material for several applications, from optoelectrics to sensors. However, its potential for spintronics applications has yet to be explored. In this work, we demonstrate that the PtSe₂/Ni₈₀Fe₂₀ heterostructure can generate large damping-like current-induced spin-orbit torques (SOT), despite the absence of spin-splitting in bulk PtSe₂. The efficiency of charge-to-spin conversion is found to be -0.1 ± 0.02 nm^-1 in PtSe₂/Ni₈₀Fe₂₀, which is 3 times that of the control sample, Ni₈₀Fe₂₀/Pt. Our band structure calculations show that the SOT due to PtSe₂ arises from an unexpectedly large spin splitting in the interfacial region of PtSe₂ introduced by the proximity magnetic field of the Ni₈₀Fe₂₀ layer. Our results open up the possibilities of using large-area PtSe₂ for energy-efficient nanoscale devices by utilizing proximity-induced SOT.