The spin-Peierls transition beyond the adiabatic approximation

Abstract

We develop a theory of the spin-Peierls transition taking into account the three dimensional character of the phonon field. Our approach does not rely on the adiabatic or mean field treatment for the phonons. It is instead based in the exact integration of the phonon field, the exact long wavelength solution of the one chain spin problem, and then a mean field approximation for the interchain interaction. We show that the spin gap and the critical temperature are strongly reduced due to the finite frequency effects of the phonon coupling transverse to the magnetic chains. We claim that our results should be applicable to the inorganic spin-Peierls compound CuGeO${}_3$. We show that the long standing discussion on absence of a soft mode in this compound can be naturally resolved within our theory.

10 pages, 5 figures

References in corpus (11)

• Exact expectation values of local fields in quantum sine-Gordon model
• Dynamics of coupled quantum spin chains
• Study of the magnetic susceptibility in the spin-Peierls system CuGeO${}_3$
• S=1/2 chains and spin-Peierls transition in TiOCl
• Quasi-1D spin-1/2 Heisenberg magnets in their ordered phase: correlation functions
• Dynamics of the Peierls-active phonon modes in CuGeO_3
• Mean Field theory of the spin-Peierls transition
• Adiabatic-antiadiabatic crossover in a spin-Peierls chain
• Magneto-elastic excitations in spin-Peierls systems
• Lattice dynamics of CuGeO${}_3$ : inelastic neutron scattering and model calculations
• Domain excitations in spin-Peierls systems

Cited by in corpus (11)

• X-ray Scattering Study of the spin-Peierls transition and soft phonon behavior in TiOCl
• Density functional study of the electronic and vibrational properties of TiOCl
• Topological solitons and bulk polarization switch in collinear type II multiferroics
• Microscopic theory for the incommensurate transition in TiOCl
• Exploring magneto-electric coupling through lattice distortions: insights from a pantograph model
• Anharmonic effects in magnetoelastic chains
• Spin Excitation Assisted by Non-Softening Phonon for Spin-Peierls Model
• Theoretical study of the magnetism in the incommensurate phase of TiOCl
• Relevance of nonadiabatic effects in TiOCl
• Incommensurate spin Luttinger liquid phase in a model for the spin-Peierls materials TiOBr and TiOCl
• Electron and phonon correlations in systems of one-dimensional electrons coupled to phonons