Ginzburg-Landau theory of dirty two band s±s_{\pm} superconductors

In this paper we study the effect of non-magnetic impurities on two-band $s_{\pm}$ superconductors by deriving the corresponding Ginzburg-Landau (GL) equation. Depending on the strength of (impurity-induced) inter-band scattering we find that there are two distinctive regions where the superconductors behave very differently. In the strong impurity induced inter-band scattering regime $T_c<<\tau^{-1}_t$, where $\tau_t\sim$ mean-life time an electron stays in one band the two-band superconductor behaves as an effective one-band dirty superconductor. In the other limit $T_c\geq\tau^{-1}_t$, the dirty two-band superconductor is described by a network of frustrated two-band superconductor grains connected by Josepshon tunnelling junctions. We argue that most pnictide superconductors are in the later regime.Comment: 4 pages, 1 figur

Topics in electrodynamics of moving media Final report, 1 May 1965 - 1 May 1966

Electrodynamics of moving medi

In-gap bound states and tunneling conductance of multiband superconductors through a normal/superconductor/superconductor junction

The tunneling conductance between a metal and a multiband s-wave superconductor with a thin layer of single-band s-wave superconductor sandwiched in between is examined in this paper. We show that an in-gap peak in conductance curve is found as a result of the formation of in-gap bound state between the single-band and multiband superconductor junctions if the phases of the superconducting order parameters of the multiband superconductor are frustrated. The implication of this result in determining the gap symmetry of the iron-based superconductors is discussed.Comment: 5 pages, 5 figure