Effective Spin Models for Spin-Phonon Chains by Flow Equations
强关联电子
2015-06-24 v2
摘要
We investigate the anti-adiabatic limit of an anti-ferromagnetic S=1/2 Heisenberg chain coupled to Einstein phonons. The flow equation method is used to decouple the spin and the phonon part of the Hamiltonian. In the effective spin model long range spin-spin interactions are generated. We determine the phase transition from a gapless state to a gapped (dimerised) phase, which occurs at a non-zero value of the spin-phonon coupling. In the effective phonon sector a phonon hardening is observed.
引用
@article{arxiv.cond-mat/0102398,
title = {Effective Spin Models for Spin-Phonon Chains by Flow Equations},
author = {Carsten Raas and Alexander Bühler and Götz S. Uhrig},
journal= {arXiv preprint arXiv:cond-mat/0102398},
year = {2015}
}
备注
RevTeX, 6 pages, 4 eps figures; final version containing some clarifications