Antiferromagnetic superexchange interactions in LaOFeAs
Abstract
From first-principles calculations, we have studied the electronic and magnetic structures of the ground state of LaOFeAs. The Fe spins are found to be collinear antiferromagnetic ordered, resulting from the interplay between the strong nearest and next-nearest neighbor superexchange antiferromagnetic interactions. The structure transition observed by neutron scattering is shown to be magnetically driven. Our study suggests that the antiferromagnetic fluctuation plays an important role in the Fe-based superconductors. This sheds light on the understanding of the pairing mechanism in these materials.
Cite
@article{arxiv.0804.3370,
title = {Antiferromagnetic superexchange interactions in LaOFeAs},
author = {Fengjie Ma and Zhong-Yi Lu and Tao Xiang},
journal= {arXiv preprint arXiv:0804.3370},
year = {2008}
}
Comments
5 pages and 7 figures; add the appendix to explain how to determine the nearest and next-nearest Fe-Fe exchange interactions J1 and J2. The overcounting on J1 and J2 in previous version in 2x2 Fe-Fe unit cell with the periodic boundary conditions has been corrected. It is found that J1 is close to J2