Nonadiabatic approach to spin-Peierls transitions via flow equations

[摘要] The validity of the adiabatic approach to spin-Peierls transitions is assessed. An alternative approach is developed which maps the initial magnetoelastic problem to an effective magnetic problem only. Thus the equivalence of magnetoelastic solitons and magnetic spinons is shown. No soft phonon is required for the transition. Temperature-dependent couplings are predicted in accordance with the analysis of experimental data.

[关键词] MATRIX RENORMALIZATION-GROUP;SOLITON LATTICE STATE;EXCITATION SPECTRUM;NEUTRON-SCATTERING;SYSTEM CUGEO3;CHAINS;DIMERIZATION;FIELDS