Spin excitations in the excitonic spin-density-wave state of the iron pnictides - Condensed Matter > Materials ScienceReport as inadecuate




Spin excitations in the excitonic spin-density-wave state of the iron pnictides - Condensed Matter > Materials Science - Download this document for free, or read online. Document in PDF available to download.

Abstract: Motivated by the iron pnictides, we examine the spin excitations in anitinerant antiferromagnet where a spin-density wave SDW originates from anexcitonic instability of nested electron-like and hole-like Fermi pockets.Using the random phase approximation RPA, we derive the Dyson equation forthe transverse susceptibility in the excitonic SDW state. The Dyson equation issolved for two different two-band models, describing an antiferromagneticinsulator and metal, respectively. We determine the collective spin-wavedispersions and also consider the single-particle continua. The results for theexcitonic models are compared with each other and also contrasted with thewell-known SDW state of the Hubbard model. Despite the qualitatively differentSDW states in the two excitonic models, their magnetic response shows manysimilarities. We conclude with a discussion of the relevance of the excitonicSDW scenario to the iron pnictides.



Author: P. M. R. Brydon, C. Timm

Source: https://arxiv.org/







Related documents