ABSTRACT
In opposition to the treatment of electrons as classical particles obeying the Maxwell-Boltzmann distribution in the Drude model, the Sommerfeld model treats them as quantum mechanical particles to which the Fermi-Dirac distribution function is applicable. After emphasizing the main differences between the two models, the assumptions of the Sommerfeld model are outlined. The behavior of a free electron Fermi gas is analyzed in one- and three-dimensions. The terminology of the Fermi sphere, Fermi surface, Fermi energy, Fermi velocity, and Fermi temperature is clarified. The density of states equation for electrons is derived. It is shown that the mobility and conductivity formulae of the Drude model continue to hold; however, interpretations for relaxation time differ.
