Issue
EPL
Volume 84, Number 6, December 2008
Article Number 67015
Number of page(s) 5
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
DOI http://dx.doi.org/10.1209/0295-5075/84/67015
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

gangx@aphy.iphy.ac.cn

received 18 August 2008; accepted in final form 20 November 2008; published December 2008
published online 12 January 2009

Abstract
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.

PACS
74.70.-b - Superconducting materials.
74.25.Jb - Electronic structure.
74.25.Ha - Magnetic properties.

© EPLA 2008