Impurity induced broadening of Drude peak in strained graphene

Abstract

The recent experimental study of the far-infrared transmission spectroscopy of monolayer graphene has shown that the Drude peak width increases by more than 10% per 1% of applied mechanical strain, while the Drude weight remains unchanged. We study the influence of the strain on the resonant impurity scattering. We propose a mechanism of augmentation of the scattering rate due to the shift in the position of resonance. Using the Lifshitz model of substitutional impurities, we investigate changes in the Drude peak weight and width as functions of the Fermi energy, impurity concentration and magnitude of the impurity potential.

Effect of resonant impurity scattering of carriers on the Drude-peak broadening in uniaxially strained graphene

“…The effect of the strain on the impurity scattering rate is characterized by the dimensionless gain parameter (35), or by its discrete analog (42), which is convenient to use in numerical calculations when the dependence of the scattering rate on strain is linear. Our main results that describe the gain for 1% strain can be summarized as follows.…”

“…In the general case, the simple relationship ( 32) is violated by the presence of defects. However, when the concentration of defects is small, |Σ(E F )| ≪ |E F |, another rather simple equation for the Drude weight, which involves the quasiparticle self-energy, is valid [42]…”

“…( 33) is not applicable (see Ref. 42) and fixing the value of E F does not imply that the Drude weight remains constant.…”