Strain effects on the spin polarization of edge currents in MoS2 zig-zag nanoribbons

Abstract

The strain effects on the edge-state transport of the zigzag monolayer for a molybdenum disulfide nanoribbon are investigated numerically using a six-band tight-binding model with KWANT, where the strain effect was absorbed into the modified hopping coefficients. For metallic edge-states in a zigzag nanoribbon, introducing both an intrinsic spin–orbit coupling and local exchange field effects breaks the spin degeneracy and spin inversion symmetry to enable spin selective transport. Changes in the energy dispersion of the metallic edge-states due to uniaxial strain are asymmetric with respect to the strain direction. Transitions from metallic to insulating edge modes occur for a tensile strain of approximately 5% along the x -direction, but no such transition has been observed up to a tensile strain of 10% along the y -direction. The edge-current transmission and spin-polarized edge-currents are determined primarily by details of the energy dispersion of edge-states and are strongly affected by the incident energy of carriers for a given strain. The fully spin-polarized edge-currents can be obtained by modulating both the Fermi energy and gate potential. The results provide useful information to implement a spin-polarized current as a potential solution for wearable spin devices. • The strain effects on the edge-state transport for a molybdenum disulfide nanoribbon. • Asymmetric change of the energy dispersion of the edge states with respect to the strain direction. • Transitions from metallic to insulating edge modes due to tensile strains. • The spin-polarized edge currents in a three terminal field effect transistor.