Unusual disorder-limited transport in Fe-based superconducting materials

COFFEE_KLATCH · Invited

Abstract

The unusual temperature dependence of the resistivity and its in-plane anisotropy observed in the Fe-based superconducting materials, particularly Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$, has been a longstanding puzzle. I discuss first the effect of impurity scattering on the temperature dependence of the average resistivity within a simple two-band model of a dirty spin density wave (SDW) metal. Within this framework[1], many of the qualitative features of the transport can be understood by accounting for the growth of spin correlations pinned by impurities above the Neel temperature, and SDW-induced Lifshitz transitions below. I then discuss implications of this picture for the anisotropy observed in untwinned crystals. [1] Y. Wang, M. N. Gastiasoro, B. M. Andersen, M. Tomic, H.O. Jeschke, Roser Valenti, I. Paul and P.J. Hirschfeld, arXiv:1408.1933

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Authors

  • Peter Hirschfeld

    University of Florida, University of Florida, USA, Department of Physics, University of Florida, Department of Physics, University of Florida, Gainesville, USA, Department of Physics, University of Florida, Gainesville, FL