Volume 84, Number 6, December 2008
Article Number 67015
Number of page(s) 5
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
Published online 12 January 2009
EPL, 84 (2008) 67015
DOI: 10.1209/0295-5075/84/67015

Electron-hole asymmetry and quantum critical point in hole-doped BaFe2As2

Gang 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-As$\hbox{--} $based 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