Excitonic Instability at the Spin-State Transition in the Two-Band Hubbard Model
Strongly Correlated Electrons
2014-04-15 v2
Abstract
Using linear response theory with the dynamical mean-field approximation we investigate the particle-hole instabilities of the two-band Hubbard model in the vicinity of the spin-state transition. Besides the previously reported high-spin--low-spin order we find an instability towards triplet excitonic condensate. We discuss the strong and weak coupling limits of the model, in particular, a connection to the spinful hard-core bosons with a nearest-neighbor interaction. Possible realization in LaCoO3 at intermediate temperatures is briefly discussed.
Keywords
Cite
@article{arxiv.1310.0669,
title = {Excitonic Instability at the Spin-State Transition in the Two-Band Hubbard Model},
author = {J. Kunes and P. Augustinsky},
journal= {arXiv preprint arXiv:1310.0669},
year = {2014}
}
Comments
9 pages, 6 figures, revised extended version