Soliton Lattice in Trans-Polyacetylene with Random Site-Type impurities11The project supported by National Natural Science Foundation of China with Grant No. 1947007 and the Trans-Century Training Programme Foundation for the Talents by the State Education Commission of China

Abstract

In order to understand the effect of disorder of impurities in doped trans-polyacetylene, we investigate the electronic states of trans-PA with random site-type impurities, especially, taken into account the Coulomb interaction between impurity ions. The randomness of impurity ions can obviously affect the electronic structures of trans-PA chain for the intermediate doping regime (%). With increasing doping level, this in turn leads to widen the soliton band and narrow the band gap. Moreover, the upper gap will appear a maximum at the critical doping level ( 6%). In addition, when the doping concentration is larger than 12%, the random distribution of impurities tends to be uniform because of being concerned with the Coulomb interaction between ions. Meanwhile, the order parameter configuration indicates that it will appear soliton lattice.