Enhanced Magnetism in Heterostructures with Transition-Metal Dichalcogenide Monolayers

Heterostructures with semiconducting transition-metal dichalcogenide offer possibilities to alter and control the magnetic properties, spin transport and spin conversion through novel interfacial coupling mechanisms. Here we report first principles simulations to investigate the structural, electronic, and magnetic properties of Fe/WSe₂/Pt heterostructure with pristine, defective, or V-doped WSe₂ [1]. The insertion of the transition-metal dichalcogenide layer leads to spin-oriented redistributions, increased total magnetization, and enhanced density of states at Fermi level regardless of presence of defects or dopants. To unravel the artificially folded bands created by the shrunk Brillouin zone in the supercells, the unfolded band structures and Fermi surfaces are obtained. We find that the semiconductor nature of the transition-metal dichalcogenide becomes diluted due to the interlayer coupling. The Fermi surfaces provide us with an in-depth understanding of the spin-resolved distribution across the interface and spin conducting channels. Subsequent transport calculations show much enhanced spin Seebeck coefficient for the Fe/WSe₂/Pt heterostructure when compared to the Fe/Pt system. Our results could be useful to interpret recent experiments reporting larger magnetization and spin Seebeck coefficients in heterostructures involving transition-metal dichalcogenide.