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arXiv · 0803.3426

Competing Orders and Spin-Density-Wave Instability in La(O$_{1-x}$F$_x$)FeAs

J. Dong·H. J. Zhang·G. Xu·Z. Li·G. Li·W. Z. Hu·D. Wu·G. F. Chen·X. Dai·J. L. Luo·Z. Fang·N. L. Wang
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Abstract

The interplay between different ordered phases, such as superconducting, charge or spin ordered phases, is of central interest in condensed matter physics. The very recent discovery of superconductivity with a remarkable T$_c$= 26 K in Fe-based oxypnictide La(O$_{1-x}$F$_x$)FeAs is a surprise to the scientific community\cite{Kamihara08}. The pure LaOFeAs itself is not superconducting but shows an anomaly near 150 K in both resistivity and dc magnetic susceptibility. Here we provide combined experimental and theoretical evidences showing that the anomaly is caused by the spin-density-wave (SDW) instability, and electron-doping by F suppresses the SDW instability and recovers the superconductivity. Therefore, the La(O$_{1-x}$F$_x$)FeAs offers an exciting new system showing competing orders in layered compounds.

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J. Dong, H. J. Zhang, G. Xu, Z. Li, G. Li, W. Z. Hu, D. Wu, G. F. Chen, X. Dai, J. L. Luo, Z. Fang, N. L. Wang. 2008-03-24. Competing Orders and Spin-Density-Wave Instability in La(O$_{1-x}$F$_x$)FeAs. https://doi.org/10.1209/0295-5075/83/27006

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