Eur. Phys. J. B 7, 233-236 (1999)
https://doi.org/10.1007/s100510050609

The spin-Peierls phase transition in the quasi-one-dimensional spin-1/2 Heisenberg model

Department of Materials Science and Technology, University of Science and Technology of China, Hefei, 230026, P.R. China Department of Physics, Nanjing University, Nanjing 210093, P.R. China

Received: 18 March 1998
Revised: 23 August 1998
Accepted: 24 August 1998
Published online: 15 January 1999

Abstract

The spin-Peierls (SP) phase transition of the inorganic compound CuGeO₃ is theoretically studied on the basis of Heisenberg model using Jordan-Wigner transformation (JWT) by mean-field approach. The magnetic interaction is considered to be the quasi-one-dimensional Cu²⁺ (spin-1/2) Heisenberg chain, and the spin-lattice distortion is expressed quasiclassically. We found that the interchain coupling between the chains leads to the occurrence of gapless dimerization (or stepped SP) phase. As the interchain coupling decreases, the difference between the dimerization temperature t_D and the gap-opening temperature t_G decreases. If the interchain coupling is small enough, then the difference should be too small to be observed experimentally.