Habib Rostami, Ali G. Moghaddam, Reza Asgari
We propose an effective lattice Hamiltonian for monolayer MoS$_2$ in order to describe the low-energy band structure and investigate the effect of perpendicular electric and magnetic fields on its electronic structure. We, first, derive a tight-binding model based on the hybridization of $d$ orbitals of Molybdenum and $p$ orbitals of Sulfur atoms and then, introduce a modified two-band continuum model of monolayer MoS$_2$ by exploiting the quasi-degenerate partitioning method. Our theory reveals a difference in electron and hole masses and provides trigonal warping effects. Furthermore, we predict a valley degeneracy breaking effect in Landau levels. Besides, we also show that application of a gate field perpendicular to the monolayer, breaks the vertical mirror symmetry and induces different potentials in the three sublayers, can slightly modify the electronic structure including the band gap and effective masses.
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http://arxiv.org/abs/1302.5901
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