Relaxation of Superconducting Fluctuations in a Two-Component Scenario with Intra- and Interband Pairings

Abstract

We study the relaxation of superconducting fluctuations in a two-component (two-band) model where the interband pair-transfer interaction and intraband effective attractions of electron-phonon nature are taken into account. The corresponding free energy and the system of Landau–Khalatnikov equations are derived. One can distinguish two different time scales in the damping of the fluctuations of superconducting order parameters in a two-band scenario. The formation of these relaxation channels is caused by the interband interaction leading to the redistribution of damping processes of the initially independent bands. The relevant relaxation times characterize the kinetics of critical and noncritical fluctuations which appear as the certain linear combinations of the deviations from the equilibrium band superconducting orders. The peculiarities of the temperature behavior of the relaxation times in dependence on intra- and interband couplings are established.