Home
For authors
Submission status

Current
Archive (English)
Archive
   Volumes 81-92
   Volumes 41-60
   Volumes 21-40
   Volumes 1-20
   Volumes 61-80
      Volume 80
      Volume 79
      Volume 78
      Volume 77
      Volume 76
      Volume 75
      Volume 74
      Volume 73
      Volume 72
      Volume 71
      Volume 70
      Volume 69
      Volume 68
      Volume 67
      Volume 66
      Volume 65
      Volume 64
      Volume 63
      Volume 62
      Volume 61
Search
VOLUME 67 (1998) | ISSUE 12 | PAGE 994
Incremental expansions for Hubbard-Peierls systems
PACS: 71.10.Fd, 75.10.Jm
The ground state energies of infinite half-filled Hubbard Peierls chains are investigated combining incremental expansion with exact diagonalization of finite chain segments. The ground state energy of equidistant infinite Hubbard ( Heisenberg) chains is calculated with a relative error of less than 3 · 10_s for all values of U using diagonali-zations of 12-site (20-site) chain segments. For dimerized chains the dimerization order parameter d as a function of the onsite repulsion interaction U has a maximum at nonzero values of U, if the electron-phonon coupling g is lower than a critical value gc. The critical value gc is found with high accuracy to be gc = 0.69. For smaller values of g the position of the maximum of d(U) is approximately 3t, and rapidly tends to zero as g approaches gc from below. We show how our method can be applied to calculate breathers for the problem of phonon dynamics in Hubbard Peierls systems.