抄録
Electron nuclear double resonance (ENDOR) measurements were performed on stretch oriented undoped cis-rich (CH)x at 4 K. The observed ENDOR line shape had spectral turning points and showed a clear anisotropy. The presence of the spin density which is comparable with the prediction of the soliton theory was directly confirmed from the maximum ENDOR frequency. The analysis of the observed line shape using a spectrum simulation method suggested that the spin density is of the form similar as those predicted by the soliton theory for finite on-site Coulomb energy. Especially the spectral turning points observed when the external magnetic field was parallel to the stretch direction of the sample were directly correlated to the existence of the negative spin density predicted by the theory.
