Piezoresistive effect in two-dimensional Dirac materials

Applying the Bir-Picus ansatz for strain-induced corrections to the electron momentum scattering time on impurities in a transition metal dichalcogenide monolayer, and taking the parameters of MoS2 for our estimations, we derive general analytical expressions describing the piezoresistive effect, the strain-induced corrections to (longitudinal) Drude conductivity, linear magnetoresistance, and the Hall conductivity of the monolayer for an arbitrary dependence of electron momentum scattering time on its energy. We show that a two-band model, even with the account of the trigonal warping of electron valleys, should be revisited for the description of the piezoresistive effect in the case of strongly degenerate electrons. Therefore, we extend the two-band model by accounting for the deformation of higher-energy bands and derive general expressions describing strain-induced corrections to the kinematic coefficients of the monolayer. Thus, the developed approach allows to estimate the deformation constants of higher-energy bands.