First principles study and empirical parametrization of twisted bilayer MoS2 based on band-unfolding

Yaohua Tan, Fan W. Chen, and Avik W. Ghosh, Applied Physics Letters , 109 (101601) (2016).
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# Abstract

We explore the band structure and ballistic electron transport in twisted bilayer $$MoS_2$$ using the density functional theory. The sphagetti like bands are unfolded to generate band structures in the primitive unit cell of the original 2H $$MoS_2$$ bilayer and projected onto the original bands of an individual layer. The corresponding twist angle dependent bandedges are extracted from the unfolded band structures. Based on a comparison within the same primitive unit cell, an efficient two band effective mass model for indirect $$\Gamma_V$$ and $$\Lambda_C$$ valleys is created and parametrized by fitting to the unfolded band structures. With the two band effective mass model, we calculate transport properties—specifically, the ballistic transmission in arbitrarily twisted bilayer $$MoS_2$$.