Superpolaron Model for Metallic Polyacetylene

概要

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XVe present a theory,' flor the metallic phase of heavily doped polyacetylene. The Hartree-Fock (HF) ground state in this sy'stem is a charged soliton (S" ) lattice that has anearly periodic long range order in the charge density as well as the one in latticedistortion. We take account of electronic correlation effects by considering super-polarons (SP's) as local fluctuations in the electronic order parametcrr (OP). They areelectrons and laoles injected into a S' lattice that make no lattice clistorviomas but areelftrapped and make local defects in the electronic OP. They make intrachain quanrum translation and interchain laopping rhrouglt dopancs,. The t'ormation energy of aSP pair is reduced by these quantum motions and become negative in a high dopingregime. Therefore, the ground state in tlais regime is a S" lattice xvirh spontaneouslyproduced SP's. The SP's may be regarded as Fermion quasi-particles. Since they par-tially occupy the translational bands of SP's, metallic properties appear in this phase.metallic polyacer)'lene, 10 extended Hubbard model, quantum Fluctuation,[charged soliton, superpolaronl
社団法人日本物理学会の論文
1992-01-15