Strain-dependent modulation of conductivity in single-layer transition-metal dichalcogenides

Quantum conductance calculations on the mechanically deformed monolayers of MoS${}_{2}$ and WS${}_{2}$ were performed using the nonequlibrium Green's functions method combined with the Landauer-B\"uttiker approach for ballistic transport together with the density-functional-based tight binding method. Tensile strain causes significant changes in the electronic structure of transition-metal dichalcogenide single layers and eventually the semiconductor-metal transition occurs for elongations as large as 11$%$ for the 2D-isotropic deformations in the hexagonal structure. This transition enhances the electron transport in otherwise semiconducting materials.