Superconducting and other phases in organic high polymers of polyacenic carbon skeletons. I. The method of sum of divergent perturbation series

Abstract

The instabilities of a normal molecular orbital state of polyacenic materials are studied within RPA with a g model for an electronic interaction. The condensed states predicted are singlet superconducting (SSC), charge density wave (CDW), and spin density wave (SDW) ones, and their phase diagram is shown. In contrast to usual one-dimensional (1D) conductors, there reveals a wide range of superconducting state, which is not overcome by CDW transition. Weakness of Peierls distortion of the present model is also contrasted with the case of polyacetylene.

Multiband Superconductivity

“…The spectrum is elucidated using the Green function method. From Green's functions that characterize the CDW, SDW, and SSC phases, we obtain a self-consistent equation according to the traditional procedure, [25][26][27][28][29][33][34][35][36] from which we can obtain expressions of the transition temperature. In the framework of the one-band model, the electronic phases are characterized by…”

Theoretical studies on superconducting and other phases: Triplet superconductivity, ferromagnetism, and ferromagnetic metal

“…In order to investigate the triplet superconductivity, ferromagnetism, and ferromagnetic metal, the procedure of Green's function technique by Kimura et al 27–30 is extended.…”

“…When the coupling constants for each scattering process is equivalent \documentclass{article}\pagestyle{empty}\begin{document}$(g^{i}_{x\alpha}(\mathbf{k})=g^{i}_{x-\alpha}(\mathbf{k})= g^{j}_{x\alpha}(\mathbf{k})=g^{j}_{x-\alpha}(\mathbf{k}))$\end{document}, it is easy to find that the correction becomes the same expressions in Ref. 27. In the next section, we consider renormalization of these parameters from a quantitative point of view.…”

Theoretical study on dependency of conductivity on structure of the proton- and electron-coupled system

“…We investigate anomalous phases of coupled systems of electrons and protons by means of the approach by Kimura et al 10–13. Before we discuss the condensed phase of the system, it is instructive to summarize the single‐particle states of the system.…”

“…In the next section, we explain a theoretical background of calculation of transition temperature of singly ordered phases as the singlet superconductivity (SSC), SDW, and CDW in terms of the temperature Green function method. Especially, we apply an approximation method known as the g model to this problem 10–17. The third section is concerned with numerical results of the energy band and transition temperature of anomalous phases.…”