Rashba spin-splitting in Janus SnXY/WXY (X, Y = S, Se, Te; X ≠ Y) heterostructures

Abstract

Janus transition metal dichalcogenide monolayers have shown a lack of mirror symmetry perpendicular to the 2D plane. The breaking of out-of-plane symmetry, along with the spin–orbit coupling, induces Rashba spin-splitting (RSS) in these materials. In this work, RSS in Janus tin dichalcogenide monolayers are studied. In addition, the heterostructures (HSs) of Janus SnXY and WXY (X, Y = S, Se, Te; X ≠ Y) monolayers are discussed. A RSS energy of about 43 meV, more significant than the room temperature energy, is observed in the Janus SnSSe/WSSe HS. The consequences of vertical strain on the semiconducting HS are examined. Compressive vertical strain enhances and tensile strain reduces, the spin-splitting. For the compressive strain of 10.4%, Janus SnSSe/WSSe HS remains semiconductor with only Rashba bands surrounding near the Fermi level. Enhanced Rashba parameter of about 0.96 eV Å and splitting energy of about 72 meV are observed. These findings confirm that Janus SnSSe/WSSe HS is a productive Rashba material for spintronic device applications.