High spin Hall conductivity in large-area type-II Dirac semimetal PtTe2

Abstract

Recently, two-dimensional transition metal dichalcogenides (TMDs) emerge as intriguing platforms for spintronics study because of their controllability in structure, stacking order, conductivity, non-trivial energy band topology and interplay between spin and pseudospin [1,2]. With strong spin-orbit coupling [3], TMDs also show great potentials in manipulation of magnetic moment by using of spin-orbit torque (SOT), however, most of the present study is restricted to the mechanically exfoliated samples with small sizes and relatively low conductivities [4,5]. Therefore, the efficiency of magnetization switching in TMD/FM bilayer might not be comparable with conventional HM/FM bilayer and not suitable for large-scale application. Here, we develop a manufacturable recipe to fabricate large-area thin films of PtTe2, a type-II Dirac semimetal, to study their capability of generating SOT [6]. PtTe2/Py bilayer was fabricated and characterized by spin-torque Ferromagnetic resonance (ST-FMR) technology. Large SOT efficiency together with high conductivity results in a giant spin Hall conductivity (0.2-2×105 h/2e (Ωm)−1) of PtTe2 thin films, which is one of the largest values among the presently reported TMDs. We further demonstrate that the SOT from PtTe2 layer can switch a perpendicularly magnetized CoTb layer efficiently. This work paves the way for employing PtTe2-like TMDs for wafer-scale spintronic device applications. **