Orbital-lattice coupling and orbital-ordering instability in iron pnictides
Department of Physics, Hanyang University - 17 Haengdang, Seongdong, Seoul 133-791, Korea
Received: 2 June 2015
Accepted: 14 October 2015
Orbital-ordering instability arising due to the intrapocket nesting is investigated for the tight-binding models of pnictides in the presence of orbital-lattice coupling. The incommensurate instabilities with small momentum, which may play an important role in the nematic-ordering transition, vary from model to model besides being more favorable in comparison to the spin-density wave instability in the absence of good interpocket nesting. We also examine the doping dependence of such instabilities. The electron-phonon coupling parameters required to induce them are compared with the first-principle calculations.
PACS: 74.70.Xa – Pnictides and chalcogenides / 74.25.Jb – Electronic structure (photoemission, etc.) / 75.25.Dk – Orbital, charge, and other orders, including coupling of these orders
© EPLA, 2015