A Theoretical Calculation of Quasiparticle Properties in Aluminum

Abstract

<p>Theoretical calculations of the renormalization of the electron mass and the quasiparticle lifetime due to the electron-phonon interaction are performed in aluminum as a function of position on the Fermi surface. The computations are carried out at finite temperature, and, in the case of the relaxation time, for finite energy above the Fermi surface.</p> <p>We present a formal development of expressions for the mass renormalization parameter and lifetime at finite temperature to second order in the electron-phonon interaction using a perturbation-theory approach, which is mathematically simpler, if less elegant, than the usual Greensfunction method. The behaviour of the resulting integrals is discussed briefly with reference to their numerical evaluation.</p> <p>Our results for the electron mass renormalization at finite temperature agree qualitatively with the expected variation of the electron wavefunctions on the Fermi surface. In terms of the results, the approximate requirements for experimental observation of the calculated increase in electronic effective mass and its anisotropy are discussed.</p> <p>A comparison of the calculated temperature dependence of the quasiparticle lifetime with experiment and with other theoretical work has important implications for the accuracy of electron phonon numerical calculations in the low-frequency region.</p>