Elementary excitations, exchange interaction and spin-Peierls transition in CuGeO3

  title={Elementary excitations, exchange interaction and spin-Peierls transition in CuGeO3},
  author={Daniel I. Khomskii and Wiebe Geertsma and Maxim Mostovoy},
  journal={Czechoslovak Journal of Physics},
The microscopic description of the spin-Peierls transition in pure and doped CuGeO3 is developed taking into account realistic details of crystal structure. It it shown that the presence of side-groups (here Ge) strongly influences superexchange along Cu−O−Cu path, making it antiferromagnetic. Nearest-neighbour and next-nearest neighbour exchange constantsJnn andJnnn are calculated. Si doping effectively segments the CuO2-chains leading toJnn (Si)≃0 or even slightly ferromagnetic. Strong… 
27 Citations
Spin-flop and spin-Peierls transition in doped CuGeO3.
Lattice dynamical effects on the peierls transition in one-dimensional metals and spin chains
The interplay of charge, spin and lattice degrees of freedom is studied for quasi-one-dimensional electron and spin systems coupled to quantum phonons. Special emphasis is put on the influence of the
  • Sb Ras
  • Physics, Materials Science
  • 1998
The study of the magnetic and resonance properties of the single crystal CuGe03 were initiated by Petrakovskii and co-authors who first discovered the sharp decrease of the magnetic susceptibility
Modeling a dimer state in CuGeO3 in the two-dimensional anisotropic Heisenberg model with alternated exchange interaction
The two-dimensional Heisenberg spin-1/2 model with alternated exchange interaction along the c axis and an anisotropic distribution of the exchange interaction in the lattice, Jb/Jc=0.1, is examined.
Magnetic resonance in quantum spin chains
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Coherent spin dynamics of solitons in the organic spin chain compounds (o-DMTTF)2X(X=Cl,Br)
We studied the magnetic properties, in particular dynamics, of the correlated spins associated with natural defects in the organic spin chain compounds ($o$-DMTTF)$_2X$ ($X$ = Br, Cl) by means of
Role of the Zhang-Rice-like exciton in optical absorption spectra of CuGeO 3 and CuGe 1-x Si x O 3 single crystals
The optical excitations in pure and Si-substituted CuGeO 3 are investigated in the 15-300 K temperature range. A structure, detected for the E field parallel to the c axis of the crystals at about
Intra-chain superexchange couplings in quasi-1D 3d transition-metal magnetic compounds
The results evidence PbCrBO4 and PbFeBO4 as antiferromagnetic (AFM) semiconductors (intra-chain AFM and inter-chain FM) and P bMnBO4 in accordance with experimental observations and M-M delocalization superexchange couplings dominating their magnetic properties.


A new theory of the spin-Peierls transition with special relevance to the experiments on TTFCuBDT
We develop a new theory of the spin-Peierls transition in spin-\textonehalf{} Heisenberg chains, treating the phonons in a mean-field random-phase approximation (RPA) as in previous work, but
Coexistence of Dimerization and Antiferromagnetism in Si-Doped CuGeO3
We have performed elastic- and inelastic-neutron-scattering experiments on a single crystal of the quasi-one-dimensional system CuGe0.993Si0.007O3. Our experimental data show unambiguously that both
Competition between Spin-Peierls Phase and Three-Dimensional Antiferromagnetic Order in CuGe1-xSixO3
We have performed magnetic-susceptibility measurements and Cu nuclear-magnetic-resonance studies on single crystals of the quasi-one-dimensional antiferromagnet CuGe1-xSixO3, with 0 ≤ x ≤ 0.1. The Si
Observation of the spin-Peierls transition in linear Cu2+ (spin-1/2) chains in an inorganic compound CuGeO3.
This Letter is the first report of an unambiguous determination of the existence of the spin-Peierls transition in an inorganic compound.
Effects of substitution of Zn for Cu in the spin-Peierls cuprate, CuGeO3: The suppression of the spin-Peierls transition and the occurrence of a new spin-glass state.
The present Letter provides the first study or the spin-Peierls system with impurities and the Zn doping causes another phase transition in the samples with 0.02≤x≤0.08, which proved to be spin-glass-like.
Quantum Magnetism of CuGeO3.
It is argued that competing exchange interactions are a general feature of organic charge transfer compounds, and that they increase the temperature at which a spin-Peierls transition takes place.
Peierls instability in Heisenberg chains
Dimerization phase transitions for $S=\frac{1}{2}$ linear antiferromagnetic chains is investigated by analogy with Peirels transitions in linear conducting chains. This analogy is very close when the
Influence of side groups on 90 degrees superexchange: A modification of the Goodenough-Kanamori-Anderson rules.
Qualitative arguments and numerical estimates show that this mechanism may be important in the inorganic spin-Peierls compound CuGeO3 and can make the 90 degrees superexchange of half-filled shells antiferromagnetic.
Antiferromagnetic Long Range Order in Disordered Spin-Peierls Systems
A theoretical possibility of the existence of disorder-induced antiferromagnetic long range order in spin-Peierls system has been presented, which will be in accordance with the recent experimental