Theory of electrical conductivity

The quantum dynamics of electrons has been investigated with the help of do uble time thermodynamic electron-Green's functions: The model Hamiltonian f or the problem consists of the state of a real crystal containing phonon sy stem (harmonic and anharmonic), electron system, localized impurities and i nteractions thereof. The disorder effects include the mass and force consta nt changes at the impurity sites. The life times for various scattering pro cess have been evaluated in the new Game work. The expression for the elect rical conductivity has been derived with the help of Kubo formalism. It is found that the electrical conductivity is not simply a function of electron energy, but, it depends on a large number of scattering events and other f actors depending on crystal characteristics,and temperature. It has been in vestigated that the electron-phonon coupling and defects play prominent rol e in the electron-transport theory and heralds the temperature dependence o f electrical conductivity.