Effect of electron-phonon interaction and temperature dependence of resistivity in some heavy fermion systems

摘要

Here we have considered the electron-phonon interaction in the Periodic Anderson Model (PAM) to describe the temperature dependence of resistivity in some heavy fermion (HF) systems. Since the resistivity is related to the imaginary part of the electron self energy, the expression of the same is evaluated from electron Green function by the double time temperature dependant Green function technique of the Zubarev type. In order to understand the effect of electron-phonon interaction in these systems, we couple the phonons to both the f-electrons as well as to the electrons of the hybridization band of both conduction and f-electrons. The influence of various model parameters, namely, the position of 4f level E ₀, the electron-phonon coupling strengths f ₁(q) and f ₂(q), the effecting coupling strength g = N(0)γ ₀2/ω ₀ have been studied on the temperature dependence of resistivity in HF systems. The numerical analysis is performed for q = 0 and for finite temperature in the static limit. The analysis of the results gives satisfactorily in comparison to the experimental observations.