Probing Spin-Charge Relation by Magnetoconductance in One-Dimensional Polymer Nanofibers

A. Choi 1, 2, K. H. Kim 1, S. J. Hong 1, M. Goh 3, 4, K. Akagi 3, R. B. Kaner 5, N. N. Kirova 6, S. A. Brazovskii 7, A. T. Johnson 8, 9, D. A. Bonnell 8, E. J. Mele 9, Y. W. Park 1

Physical Review B (Condensed Matter) 86 (2012) 155423

Polymer nanofibers are one-dimensional organic hydrocarbon systems containing conducting polymers where the non-linear local excitations such as solitons, polarons and bipolarons formed by the electron-phonon interaction were predicted. Magnetoconductance (MC) can simultaneously probe both the spin and charge of these mobile species and identify the effects of electron-electron interactions on these nonlinear excitations. Here we report our observations of a qualitatively different MC in polyacetylene (PA) and in polyaniline (PANI) and polythiophene (PT) nanofibers. In PA the MC is essentially zero, but it is present in PANI and PT. The universal scaling behavior and the zero (finite) MC in PA (PANI and PT) nanofibers provide evidence of Coulomb interactions between spinless charged solitons (interacting polarons which carry both spin and charge).

  • 1. Department of Physics and Astronomy,
    Seoul National University
  • 2. WCU Flexible Nanosystems,
    Korea University
  • 3. Department of Polymer Chemistry,
    Kyoto University
  • 4. Institute of Advanced Composite Materials,
    KIST
  • 5. Department of Chemistry and Biochemistry,
    UCLA
  • 6. Laboratoire de Physique des Solides (LPS),
    CNRS : UMR8502 – Université Paris XI - Paris Sud
  • 7. Laboratoire de Physique Théorique et Modèles Statistiques (LPTMS),
    CNRS : UMR8626 – Université Paris XI - Paris Sud
  • 8. Nano-Bio Interface Center,
    University of Pennsylvania
  • 9. Department of Physics and Astronomy,
    University of Pennsylvania