Magnetic Proximity induced efficient charge-to-spin conversion in large area PtSe${}_2$/Ni${}_{80}$Fe${}_{20}$ heterostructures

As a topological Dirac semimetal with controllable spin-orbit coupling and conductivity, PtSe${}_2$, a transition-metal dichalcogenide, is a promising material for several applications from optoelectric to sensors. However, its potential for spintronics applications is yet to be explored. In this work, we demonstrate that PtSe${}_2$/Ni${}_{80}$Fe${}_{20}$ heterostructure can generate a large damping-like current-induced spin-orbit torques (SOT), despite the absence of spin-splitting in bulk PtSe${}_2$. The efficiency of charge-to-spin conversion is found to be $(-0.1\pm 0.02)$~nm${}^{-1}$ in PtSe${}_2$/Ni${}_{80}$Fe${}_{20}$, which is three times that of the control sample, Ni${}_{80}$Fe${}_{20}$/Pt. Our band structure calculations show that the SOT due to the PtSe${}_2$ arises from an unexpectedly large spin splitting in the interfacial region of PtSe${}_2$ introduced by the proximity magnetic field of the Ni${}_{80}$Fe${}_{20}$ layer. Our results open up the possibilities of using large-area PtSe${}_2$ for energy-efficient nanoscale devices by utilizing the proximity-induced SOT.