First-principle study on quintuple-atomic-layer Janus MTeSiX[formula omitted] (M= Mo, W; X=N, P, As) monolayers with intrinsic Rashba spin-splitting and Mexican hat dispersion

Abstract

In this research, inspired by the electron’s spin nature and its unique induced phenomena, we probe into the structural, electronic and spintronic features of Janus MTeSiX2 (M= Mo, W; X=N, P, As) monolayers. Phonon dispersions and cohesive energies confirm the stability of the Janus monolayers. All the monolayers demonstrate a semiconducting behavior with a considerable bandgap. We have encountered an intrinsic vertical electric field caused by breaking out-of-plane symmetry that induces Rashba spin–orbit coupling. In addition to Rashba spin-splitting, we saw a non-parabolic Mexican hat-like dispersion at the Γ-point of the valence band. Furthermore, due to the unique features of the compounds with N atom, we have studied these properties for MoTeGeN2 and WTeGeN2 monolayers. Finally, exerting tensile strain reveals considerable manipulation of the electronic and spintronic properties of studied Janus monolayers. Overall, our findings enrich Janus 2D materials family and introduce them as valuable candidates for next-generation spintronic devices.