Abstract
We study a spin S quantum Heisenberg model on the Fe lattice of the rare-earth oxypnictide superconductors. Using both large S and large N methods, we show that this model exhibits a sequence of two phase transitions: from a high-temperature symmetric phase to a narrow region of intermediate "nematic" phase, and then to a low-temperature spin ordered phase. Identifying phases by their broken symmetries, these phases correspond precisely to the sequence of structural (tetragonal to monoclinic) and magnetic transitions that have been recently revealed in neutron-scattering studies of LaFeAsO. The structural transition can thus be identified with the existence of incipient ("fluctuating") magnetic order.
Published in:
Physical Review B 77,22 (2008) 224509;
Link to original published article:
http://dx.doi.org/10.1103/PhysRevB.77.224509
Keywords
Physics, Condensed Matter
Date of Version
January 2008
Recommended Citation
Fang, C.; Yao, H.; Tsai, W. F.; Hu, J. P.; and Kivelson, S. A., "Theory of electron nematic order in LaFeAsO" (2008). Department of Physics and Astronomy Faculty Publications. Paper 743.
https://docs.lib.purdue.edu/physics_articles/743