Electron–phonon interaction-driven dynamic conductivity in monolayer phosphorene with broken inversion symmetry

Abstract

Electronic transport in inversion symmetry broken monolayer phosphorene under the influence of electron–phonon interaction is investigated. Such interaction renormalizes the band structure, leading to a significant modification of electron dynamics, which depends on the interaction strength. We find that the imaginary part of the self-energy remains minimal within a particular region of energy ℏω, where the quasiparticle has zero density of final states. It turns out that the emission of phonon is not allowed in that energy range. At the boundary of this region, there is a sudden increase in the imaginary part of the self-energy, where its real part exhibits singular behavior around specific energies. In addition, it is shown that dynamic optical conductivity exhibits remarkable effects in the presence of the electron–phonon interaction. In particular, it remains minimal in a particular region of energy ℏω, then it increases monotonically and hits the peak of the main absorption edge. Moreover, we find that the dynamic optical conductivity changes significantly with the change in electron–phonon interaction strength, temperature, phonon energy, chemical potential, and bandgap in the energy spectrum of the system. Both the real and imaginary parts of the self-energy acquire energy dependence that reflects phonon structure and leads to a shift in the conductivity peak of the longitudinal optical conductivity.