Using a generalized two-fluid pictures for the charge of superconductor and ordinary Boltzmann equation for quasiparticle excitations, the effect of frequency and wave-vector dependent electromagnetic perturbation on charge imbalance near transition temperatureT_C is studied. In a situatiod where both the effective charge and distribution function of quasiparticles deviate from their equilibrium values, the charge imbalance is shown to possess a propagating solution at frequencies greater than inelastic scattering rate. In situations where charge imbalance is created by injection of quasiparticles, the charge imbalance relaxation rate is shown to decrease. We also study the effect of applied perturbation on quasiparticle diffusion length and hence on superconductor—normal interface boundary resistance.

Using a generalised two-fluid picture for the charge of a superconductor, the generation of charge imbalance by a temperature gradient under different conditions is studied. The voltage developed by a temperature gradient in the presence of supercurrent is estimated. The results agree with experiment. The results obtained for the generation of charge imbalance in the absence of imposed current agree with those obtained using other techniques.