ABSTRACT
This chapter examines how the temperature variations arise. The temperature Green's function is useful because it will allow to calculate the thermodynamic behavior of the system. The definition of the temperature Green's function is made simply by taking account of the fact that there exists both a distribution function in the system and a number of both full and empty states. The anti-periodicity of the temperature Green's function for electrons insures that they are described by the Fermi–Dirac distribution. The temperature dependence of the phase coherence time is less well understood but generally is thought to be limited by electron–electron scattering, particularly at low temperatures. At higher temperatures, phonon scattering can introduce phase breaking. At high temperatures, the lattice interaction becomes important, and energy exchange with the phonon field will damp the phase coherence.
