Electron-hole asymmetry and quantum critical point in hole-doped BaFe2As2Gang Xu, Haijun Zhang, Xi Dai and Zhong Fang
Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences Beijing 100190, China
received 18 August 2008; accepted in final form 20 November 2008; published December 2008
published online 12 January 2009
We show, from first-principles calculations, that the hole-doped side of Fe-Asbased compounds is different from its electron-doped counterparts. The electron side is characterized as an itinerant metal with Fermi surface nesting, and SDW-to-NM quantum critical point (QCP) is realized by doping. For the hole-doped side, on the other hand, orbital-selective magnetic ordering develops together with checkboard anti-ferromagnetic (AF) ordering without lattice distortion. A unique SDW-to-AF QCP is achieved, and the J2 = J1/2 criterion (in the approximate J1&J2 model) is satisfied at a hole-doping level of about x = 0.7. The observed superconductivity is located in the vicinity of QCP for both sides.
74.70.-b - Superconducting materials.
74.25.Jb - Electronic structure.
74.25.Ha - Magnetic properties.
© EPLA 2008