Magnetic-Proximity-Induced Efficient Charge-to-Spin Conversion in Large-Area PtSe/NiFe Heterostructures.

As a topological Dirac semimetal with controllable spin-orbit coupling and conductivity, PtSe, 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 PtSe/NiFe heterostructure can generate large damping-like current-induced spin-orbit torques (SOT), despite the absence of spin-splitting in bulk PtSe. The efficiency of charge-to-spin conversion is found to be -0.1 ± 0.02 nm in PtSe/NiFe, which is 3 times that of the control sample, NiFe/Pt. Our band structure calculations show that the SOT due to PtSe arises from an unexpectedly large spin splitting in the interfacial region of PtSe introduced by the proximity magnetic field of the NiFe layer. Our results open up the possibilities of using large-area PtSe for energy-efficient nanoscale devices by utilizing proximity-induced SOT.