The kondo effect and the pauli susceptibility in polyacetylene

Summary form only given. In this work we explain both the anomalous 1nT behavior of the conductivity and the origin of the Pauli susceptibility in the metallic state of Highly-Conducting trans-Polyacetylene (HCPA). First we establish within the context of continuum version of the SSH Hamiltonian that a soliton lattice persists at metallic doping levels and reasonable values for the electron correlations. We show, nonetheless, that a soliton lattice can give rise to a Pauli susceptibility that is in excellent with experiment by virtue of the closing of the soliton levels as the system is doped. The role of correlations on the Pauli susceptibility is also explored. In addition we show that the 1nT dependence of the conductivity arises from the formation of a Kondo resonance at low temperatures. We establish this result from a perturbative 3rd order calculation starting from the TLM conduction band coupled to an Anderson U-defect. We show that a Kondo singlet bound state forms provided that the Peierls gap is greatly reduced to about (0.5eV) by the formation of a soliton band in the metallic state. A residual gap of this value is in agreement with our previous calculations of the closing of the soliton gap in the metallic state. From renormalization calculations, we estimate the range of parameters for which Kondo scattering is significant in the metallic phase of polyacetylene.