Elementary excitations, exchange interaction and spin-Peierls transition in CuGeO3

@article{Khomskii1996ElementaryEE,
  title={Elementary excitations, exchange interaction and spin-Peierls transition in CuGeO3},
  author={Daniel I. Khomskii and Wiebe Geertsma and Maxim Mostovoy},
  journal={Czechoslovak Journal of Physics},
  year={1996},
  volume={46},
  pages={3239-3246}
}
The microscopic description of the spin-Peierls transition in pure and doped CuGeO3 is developed taking into account realistic details of crystal structure. It it shown that the presence of side-groups (here Ge) strongly influences superexchange along Cu−O−Cu path, making it antiferromagnetic. Nearest-neighbour and next-nearest neighbour exchange constantsJnn andJnnn are calculated. Si doping effectively segments the CuO2-chains leading toJnn (Si)≃0 or even slightly ferromagnetic. Strong… 
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