Quantum Criticality in the 122 Iron Pnictide Superconductors Emerging from Orbital-Selective Mottness
Abstract
The twin issues of the nature of the normal state and competing order(s) in the iron arsenides are central to understanding their unconventional, high-Tc superconductivity. We use a combination of transport anisotropy measurements on detwinned Sr(Fe(1-x)Co(x))2As2 single crystals and local density approximation plus dynamical mean field theory (LDA + DMFT) calculations to revisit these issues. The peculiar resistivity anisotropy and its evolution with x are naturally interpreted in terms of an underlying orbital-selective Mott transition (OSMT) that gaps out the dxz or dyz states. Further, we use a Landau-Ginzburg approach using LDA + DMFT input to rationalize a wide range of anomalies seen up to optimal doping, providing strong evidence for secondary electronic nematic order. These findings suggest that strong dynamical fluctuations linked to a marginal quantum-critical point associated with this OSMT and a secondary electronic nematic order constitute an intrinsically electronic pairing mechanism for superconductivity in Fe arsenides.
Keywords
Cite
@article{arxiv.1412.1034,
title = {Quantum Criticality in the 122 Iron Pnictide Superconductors Emerging from Orbital-Selective Mottness},
author = {S. D. Das and M. S. Laad and L. Craco and J. Gillett and V. Tripathi and S. E. Sebastian},
journal= {arXiv preprint arXiv:1412.1034},
year = {2015}
}
Comments
9 pages, revtex4-1, published version