Charge imbalance in non-equilibrium superconductors

Presents a review of a number of phenomena in non-equilibrium superconductors which are usually described in terms of quasiparticle branch imbalance. It is shown how these may be described in terms of a two-component model for the charge, in which part of the charge is associated with the quasiparticles and the remainder with the superconducting electrons. Compares this model with the usual two-fluid model, and considers applications to situation of experimental interest, including tunnel injection experiments, the Carlson-Goldman collective mode, and quasiparticle diffusion near phaseslip centres. In addition describes a number of thermoelectric phenomena, including generation of charge imbalance in a current-carrying superconductor in a temperature gradient.