K. Yonemitsu et M. Imada, SPIN GAP IN ONE-DIMENSIONAL ELECTRON-PHONON SYSTEMS, Molecular crystals and liquid crystals science and technology. Section A, Molecular crystals and liquid crystals, 285, 1996, pp. 223-228
The exponents of spin and charge correlations of one-dimensional elect
ron systems are calculated by a renormalization-group method. We study
combined effects of electron-phonon interaction and the Umklapp proce
ss on renormalization flows. As scattering processes are successively
integrated out, these two processes are interfered with each other dep
ending on the type of electron-phonon coupling, phonon frequency and f
illing. We demonstrate how these factors control a spin gap formation
and density-wave/superconductor correlations.