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The J_1-J_2 model revisited : Phenomenology of CuGeO_3

V. N. Muthukumar·Claudius Gros·Roser Valenti·M. Weiden·C. Geibel·F. Steglich·P. Lemmens·M. Fischer·G. Güntherodt
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Abstract

We present a mean field solution of the antiferromagnetic Heisenberg chain with nearest (J_1) and next to nearest neighbor (J_2) interactions. This solution provides a way to estimate the effects of frustration. We calculate the temperature-dependent spin-wave velocity, v_s(T) and discuss the possibility to determine the magnitude of frustration J_2/J_1 present in quasi 1D compounds from measurements of v_s(T). We compute the thermodynamic susceptibility at finite temperatures and compare it with the observed susceptibility of the spin-Peierls compound CuGeO_3. We also use the method to study the two-magnon Raman continuum observed in CuGeO_3 above the spin-Peierls transition.

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V. N. Muthukumar, Claudius Gros, Roser Valenti, M. Weiden, C. Geibel, F. Steglich, P. Lemmens, M. Fischer, G. Güntherodt. 1996-11-04. The J_1-J_2 model revisited : Phenomenology of CuGeO_3. https://doi.org/10.1103/physrevb.55.5944

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