Indexed by:Journal paper Correspondence Author:Zhang Hai-Jun Co-author:Fang Zhong,Dai Xi,Xu Gang Journal:Chinese Physics Letters Included Journals:SCI Discipline:物理学 Document Type:J Volume:26 Issue:1 Page Number:017401 Date of Publication:2009-01-01 Impact Factor:0.972 Abstract:The Fermi surfaces (FS) of LaOFeAs (in kz = 0 plane) consist of two hole-type circles around Γ point, which do not touch each other, and two electron-type co-centred ellipses around the 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 therefore suggested that the inter-orbital fluctuation is important to understand the unconventional superconductivity in these materials. Links to published journals:https://iopscience.iop.org/article/10.1088/0256-307X/26/1/017401/meta