Electron-hole asymmetry and quantum critical point in hole-doped BaFe 2 As 2

We show, from first-principles calculations, that the hole-doped side of Fe-As–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 J 2 = J 1 /2 criterion (in the approximate J 1 & J 2 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.