Giant Rashba-type splitting in molybdenum-driven bands ofMoS2/Bi(111)heterostructure

Abstract

We investigate the electronic band structure of the MoS 2 /Bi(111) heterostructure, for which the supercell calculation is performed due to the lattice mismatch between two structures but the effective primitive cell is recovered by using the band unfolding technique. It is found that the strong molybdenum-bismuth band hybridization together with a generation of the interfacial dipole field induces the giant Rashba-type splitting accompanying the proper spin topology in molybdenum-driven bands at the point. Similar splittings are also found in the heterostructure with other transition-metal dichalcogenides, i.e., with MoSe 2 , WS 2 , and WSe 2 .

Orbital angular momentum analysis for giant spin splitting in solids and nanostructures

“…Our DFT calculations show that WSe 2 monolayer on top of the Bi bilayer have chiral behaviors of OAM near the top of the valence bands at Γ, because the Bi bilayer plays a similar role to the external field E ext in breaking the mirror symmetry. Resulting spin splitting near Γ is consistent with the previous report 47 .…”

Rashba effect and enriched spin-valley coupling in GaX / MX2 ( M = Mo, W; Zhang1, Schwingenschlögl2 2018Phys. Rev. B683440View full textAdd to dashboardCite

“…Experimentally, it has been observed in semiconductor quantum wells [21,22], surfaces of heavy metals [23][24][25][26], and polar semiconductors like BiTeI [27]. Theoretical insights have been reported for several two-dimensional materials, in particular graphene [28,29], LaOBiS 2 films [30], polar transitionmetal dichalcogenide monolayers [31], and the MoS 2 /Bi(111) heterostructure [32].…”

Effective tight-binding model forMX2under electric and magnetic fields

“…The splitting has the familiar Mexican hat shape consistent with the calculations on MoS 2 /Bi(111) heterostructures. 16 The effects of magnetic field are shown in the bottom panel of Fig. 7.…”

“…Supercell calculations of MX 2 on Bi(111) heterostructures show giant Rashba splitting of the bands near Γ. 16 Tight-binding (TB) based model Hamiltonian approaches are ideally suited to study the effects of small perturbations such as electric fields on d orbitals systems. [17][18][19] For MX 2 , an effective two band k · p model valid around K point has been widely used to study the transport, optical and magnetic properties.…”