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arXiv · 0803.4487

Enhanced Orbital Degeneracy in Momentum Space for LaOFeAs

Hai-Jun Zhang·Gang Xu·Xi Dai·Zhong Fang
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Abstract

The Fermi surfaces (FS) of LaOFeAs (in $k_z$=0 plane) consist of two hole-type circles around $Γ$ point, which do not touch each other, and two electron-type co-centered ellipses around M point, which are degenerate along the M-X line. By first-principles calculations, here we show that additional degeneracy exists for the two electron-type FS, and the crucial role of F-doping and pressure is to enhance this orbital degeneracy. It is suggested that the inter-orbital fluctuation is the key point to understand the unconventional superconductivity in these materials.

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Hai-Jun Zhang, Gang Xu, Xi Dai, Zhong Fang. 2008-04-17. Enhanced Orbital Degeneracy in Momentum Space for LaOFeAs. https://doi.org/10.1088/0256-307x%2F26%2F1%2F017401

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