Journal of Physics-Condensed Matter
Considering the inter-site electron-electron interaction, we investigate the ground state and spin-wave excitation of a theoretical model proposed for quasi-one-dimensional pi-conjugated organic polymer ferromagnets. Within mean-field theory, the ground state of the system is shown to be a high-spin ferromagnetic state due to the topological structure of the system. By employing the random-phase approximation (RPA), the spin-wave excitation spectrum is obtained. It is found that the acoustic spin-wave mode displays the feature of the ferromagnetic magnon, and the inter-sire electron-electron interaction has influence on it. With the increase of inter-site electron-electron interaction, the high-spin ferromagnetic ground state of the system will be unstable.
关键词:
hubbard-model;ferromagnet;polyacetylene
