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From one to two dimensions in quantum spin systems

A. Fledderjohann·K. -H. Mütter·M. -S. Yang·M. Karbach
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Abstract

We study the first derivative of the staggered magnetization squared $dm^†(θ)^2/dθ$ and the second derivative $d^2e_0(θ)/dθ^2$ of the ground state energy per site. The parameter $θ$ controls the anisotropy between horizontal and vertical couplings in a two-dimensional (2D) spin-1/2 antiferromagnetic Heisenberg model. It is shown, that both derivatives diverge at $θ=1$, where the anisotropic 2D model reduces to the 1D model.

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A. Fledderjohann, K. -H. Mütter, M. -S. Yang, M. Karbach. 1997-11-04. From one to two dimensions in quantum spin systems. https://doi.org/10.1103/physrevb.57.956

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