Spin-Phonon Chains with Bond Coupling
摘要
We investigate the antiadiabatic limit of an antiferromagnetic S=1/2 Heisenberg chain coupled to Einstein phonons via a bond coupling. The flow equation method is used to decouple the spin and the phonon part of the Hamiltonian. In the effective spin model longer range spin-spin interactions are generated. The effective spin chain is frustrated. The resulting temperature dependent couplings are used to determine the magnetic susceptibility and to determine the phase transition from a gapless state to a dimerized gapped phase. The susceptibilities and the phase diagram obtained via the effective couplings are compared with independently calculated quantum Monte Carlo results.
引用
@article{arxiv.cond-mat/0110298,
title = {Spin-Phonon Chains with Bond Coupling},
author = {Carsten Raas and Ute Löw and Götz S. Uhrig and Rainer W. Kühne},
journal= {arXiv preprint arXiv:cond-mat/0110298},
year = {2007}
}
备注
RevTeX 4, 8 pages, 8 eps figures; final version containing some minor changes and an additional figure