Reply to Comment by E. Babaev and M. Silaev, arXiv:1105.3756

The criticism of Babaev and Silaev notwithstanding, we conclude that our analysis is correct. We have found in our papers on two-band superconductors close to Tc, where the Ginzburg-Landau (GL) theory applies, that these materials are characterized by a single order parameter, governed by a single correlation length. In the GL domain, the order parameters of individual bands are proportional to each other. This happens due to the unavoidable inter-band Josephson coupling. Consequently, in the regime where the GL theory applies, these systems are either type-I or type-II superconductors with no room for so called "1.5-type" superconductivity. This conclusion does not mean that at lower temperatures, outside of the GL domain, the inter-vortex interaction cannot have interesting properties, however, the latter cannot be addressed with the standard GL formalism.Comment: 2 page

Post-transient relaxation in graphene after an intense laser pulse

High intensity laser pulses were recently shown to induce a population inverted transient state in graphene [T. Li et al. Phys. Rev. Lett. 108, 167401 (2012)]. Using a combination of hydrodynamic arguments and a kinetic theory we determine the post-transient state relaxation of hot, dense, population inverted electrons towards equilibrium. The cooling rate and charge-imbalance relaxation rate are determined from the Boltzmann-equation including electron-phonon scattering. We show that the relaxation of the population inversion, driven by inter-band scattering processes, is much slower than the relaxation of the electron temperature, which is determined by intra-band scattering processes. This insight may be of relevance for the application of graphene as an optical gain medium.Comment: 10 pages, 4 figures, submitted as contribution of the IMPACT Special Topics series of the EP