The J₁-J₂ model revisited: Phenomenology of CuGeO₃

الأصل · EN

We present a mean field solution of the antiferromagnetic Heisenberg chain with nearest (J₁) and next to nearest neighbor (J₂) interactions. This solution provides a way to estimate the effects of frustration. We calculate the temperature-dependent spin-wave velocity, vₛ(T) and discuss the possibility to determine the magnitude of frustration J₂/J₁ present in quasi 1D compounds from measurements of vₛ(T). We compute the thermodynamic susceptibility at finite temperatures and compare it with the observed susceptibility of the spin-Peierls compound CuGeO₃. We also use the method to study the two-magnon Raman continuum observed in CuGeO₃ above the spin-Peierls transition.