The intrinsic electronic phase diagram of iron-oxypnictide superconductors
Abstract
We present the first comprehensive derivation of the intrinsic electronic phase diagram of the iron-oxypnictide superconductors in the normal state based on the analysis of the electrical resistivity $\rho$ of both LaFeAsO$_{1-x}$F$_x$ and SmFeAsO$_{1-x}$F$_x$ for a wide range of doping. Our data give clear-cut evidence for unusual normal state properties in these new materials. In particular, the emergence of superconductivity at low doping levels is accompanied by distinct anomalous transport behavior in $\rho$ of the normal state which is reminiscent of the spin density wave (SDW) signature in the parent material. At higher doping levels $\rho$ of LaFeAsO$_{1-x}$F$_x$ shows a clear transition from this pseudogap-like behavior to Fermi liquid-like behavior, mimicking the phase diagram of the cuprates. Moreover, our data reveal a correlation between the strength of the anomalous features and the stability of the superconducting phase. The pseudogap-like features become stronger in SmFeAsO$_{1-x}$F$_x$ where superconductivity is enhanced and vanish when superconductivity is reduced in the doping region with Fermi liquid-like behavior.
- Publication:
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arXiv e-prints
- Pub Date:
- November 2008
- DOI:
- 10.48550/arXiv.0811.1601
- arXiv:
- arXiv:0811.1601
- Bibcode:
- 2008arXiv0811.1601H
- Keywords:
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- Condensed Matter - Superconductivity;
- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- EPL, 87 (2009) 17005