title: Multiple self-localized electronic states in trans-polyacetylene.
abstract: Electronic structure calculations on a conjugated polymer chain by Hartree-Fock and density functional theory show a sequence of self-localized states, which stand in contrast to the single self-localized soliton state described by the Su-Schrieffer-Heeger model Hamiltonian. An extended Hubbard model, which treats electron-electron interactions up to second neighbors, is constructed to demonstrate that the additional states arise from a strong band-bending effect due to the presence of localized electric fields of charged solitons. We suggest the optical response of these electronic states may be associated with the near-edge oscillations observed in photo-induced absorption spectra. Our calculations indicate further that in the presence of counterions, the additional localized states continue to exist. Implications regarding soliton mobility and high-resolution ion sensing are briefly discussed.
authors.affiliation: Departments of Nuclear Science and Engineering and Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Xi
authors.initials: X
authors.lastname: Lin
authors.forename: Ju
authors.initials: J
authors.lastname: Li
authors.forename: Clemens J
authors.initials: CJ
authors.lastname: Först
authors.forename: Sidney
authors.initials: S
authors.lastname: Yip
mesh_terms: D000114:Acetylene / Q000031:analogs & derivatives* / Q000737:chemistry; D004581:Electronics; D007477:Ions / Q000737:chemistry*; D008433:Mathematics; D008956:Models, Chemical; D009716:Numerical Analysis, Computer-Assisted; D011108:Polymers / Q000737:chemistry*; D053279:Polyynes
chemical_list: D007477:Ions; D011108:Polymers; D053279:Polyynes; D000114:Acetylene