Perfect valley polarization in MoS2

  • Amin Heshmati-Moulai
  • Hamidreza Simchi
  • Mahdi Esmaeilzadeh
Regular Article
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Abstract

We study perfect valley polarization in a molybdenum disulfide (MoS2) nanoribbon monolayer using two bands Hamiltonian model and non-equilibrium Green’s function method. The device consists of a one-dimensional quantum wire of MoS2 monolayer sandwiched between two zigzag MoS2 nanoribbons such that the sites A and B of the honeycomb lattice are constructed by the molecular orbital of Mo atoms, only. Spin-valley coupling is seen in energy dispersion curve due to the inversion asymmetry and time-reversal symmetry. Although, the time reversal symmetry is broken by applying an external magnetic field, the valley polarization is very small. A valley polarization equal to 46% can be achieved using an exchange field of 0.13 eV. It is shown that a particular spin-valley combination with perfect valley polarization can be selected based on a given set of exchange field and gate voltage as input parameters. Therefore, the valley polarization can be detected by detecting the spin degree of freedom.

Keywords

Mesoscopic and Nanoscale Systems 

Copyright information

© EDP Sciences, SIF, Springer-Verlag GmbH Germany 2017

Authors and Affiliations

  • Amin Heshmati-Moulai
    • 1
  • Hamidreza Simchi
    • 1
    • 2
  • Mahdi Esmaeilzadeh
    • 1
  1. 1.Department of PhysicsIran University of Science and TechnologyTehranIran
  2. 2.Semiconductor Technology Center, 19575-199 TehranIran

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