Orbital-transverse density-wave instabilities in iron-based superconductors

¹ Department of Physics and Center of Theoretical and Computational Physics, The University of Hong Kong Pokfulam Road, Hong Kong, China
² National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University Nanjing 210093, China
³ Department of Physics, Renmin University of China - Beijing, China

^a zj@minus4.org
^b jxli@nju.edu.cn
^c zwang@hkucc.hku.hk

Received: 26 October 2010
Accepted: 21 January 2011

Abstract

Besides the conventional spin-density-wave (SDW) state, an orbital-transverse density-wave (OTDW) state is shown to exist generally in multi-orbital systems. We demonstrate that the orbital character of Fermi surface nesting plays an important role in density responses. The relationship between antiferromagnetism and structural phase transition in LaFeAsO (1111) and BaFe₂As₂ (122) compounds of iron-based superconductors may be understood in terms of the interplay between the SDW and OTDW with a five-orbital Hamiltonian.