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

초록

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.

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