Unconventional disorder effects in correlated superconductors

Abstract

The understanding of disorder has profoundly influenced the development of condensed matter physics, explaining such fundamental effects as, for example, the transition from ballistic to diffusive propagation, and the presence of quantized steps in the quantum Hall effect. For superconductors, the response to disorder reveals crucial information about the internal gap symmetries of the condensate, and thereby the pairing mechanism itself. The destruction of superconductivity by disorder is traditionally described by Abrikosov-Gor'kov (AG) theory, which however ignores spatial modulations and ceases to be valid when impurities interfere, and interactions become important. Here we study the effects of disorder on unconventional superconductors in the presence of correlations, and explore a completely different disorder paradigm dominated by strong deviations from standard AG theory due to generation of local bound states and cooperative impurity behavior driven by Coulomb interactions. Specifically we explain under which circumstances magnetic disorder acts as a strong poison destroying high-Tc superconductivity at the sub-1% level, and when non-magnetic disorder, counter-intuitively, hardly affects the unconventional superconducting state while concomitantly inducing an inhomogeneous full-volume magnetic phase. Recent experimental studies of Fe-based superconductors have discovered that such unusual disorder behavior seem to be indeed present in those systems.

6 pages, 5 figures, and Supplementary material

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Cited by in corpus (9)

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• Towards a quantitative description of tunneling conductance of superconductors: application to LiFeAs
• From immunity to sudden death: Effects of strong disorder in strongly correlated superconductors
• Effective pairing theory for strongly correlated d-wave superconductors
• Role of magnetic dopants in the phase diagram of Sm1111 pnictides: The Mn case
• Disorder and Zeeman coupling induced gap-filling states in the nodeless chiral superconducting Bi/Ni bilayer system
• Impurity-induced magnetic droplet in unconventional superconductors near magnetic instability: Application to Nd doped $\mathbf{CeCoI}{\mathbf{n}}_5$
• Impurity effects on spin dynamics in magnetic and superconducting iron pnictides and chalcogenides
• Local imaging of diamagnetism in proximity coupled niobium nano-island arrays on gold thin films