Theoretical evidence of the spin–valley coupling and valley polarization in two-dimensional MoSi₂X₄ (X = N, P, and As)

Abstract

Predicted spin–valley coupling and valley polarization in two-dimensional MoSi2X4 (X = N, P, and As).

Vertical Strain-Induced Modification of the Electrical and Spin Properties of Monolayer MoSi2X4 (X= N, P, As and Sb)

“…The lattice constant of MoSi 2 N 4 is 2.928 Å that is close to experimental result 9 . The lattice constants of MoSi 2 P 4 and MoSi 2 As 4 are also 3.486 and 3.633 Å, respectively, that are compatible with previous studies 18,24 . The lattice constant increases for the compounds with heavier X elements.…”

“…These values which are in good agreement with experimental work 9 , are 1.73 and 1.721 eV, respectively. The bandgap of MoSi 2 P 4 without(with) SOC is 0.772(0.648) eV that is near to 0.61 eV reported for with SOC 18 . The bandgap of MoSi 2 As 4 decreases from 0.664 to 0.525eV with applying spin-orbit coupling, while the values of 0.6eV and 0.41-0.5 eV are reported for without and with spin-orbit coupling consideration, respectively 9,18,24,30 .…”

“…These monolayers have been also predicted to exceed monolayer MoS 2 due to fascinating valleytronic properties, for instance, multiple-folded valleys in monolayer MoSi 2 As 4 . The lack of inversion symmetry along with strong spin-orbit coupling from transition metal elements in the MA 2 Z 4 family results in two inequivalent valleys (K and K') with sizable spin-splitting and spinvalley coupling 18 . For example, WSi 2 N 4 demonstrates a large spin-splitting at both conduction and valence bands at K and K'-valleys together with spin-valley coupling.…”

Tunable electronic and magnetic properties of MoSi2N4 monolayer via vacancy defects, atomic adsorption and atomic doping

“…The valley-dependent properties of MoSi 2 N 4 monolayer with a pair of Dirac-type valleys have been reported, suggesting that it is a beneficial 2D material for spintronic applications [53,54]. Furthermore, it is found out that the valley polarization can be created by doping the MoSi 2 X 4 (X=N, P, As) with V atom [55]. The high thermal conductivity of the MoSi 2 N 4 is investigated [56].…”

Novel Two-Dimensional Layered MoSi2Z4 (Z = P, As): New Promising Optoelectronic Materials

“…Due to the intrinsic inversion symmetry breaking and strong spin-orbital coupling, remarkable spin-valley coupling in the inequivalent valleys at K and K points can be found for MoSi 2 X 4 (X = N, P, As). It induces spin-valley coupled optical selection properties, which can be tuned by in-plane strain [23]. Beyond traditional two-level valleys, monolayer MoSi 2 N 4 shows multiple folded valleys, implying an additional intrinsic degree of freedom.…”