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Logarithmic corrections to correlation decay in two-dimensional random-bond Ising systems

Jean C. Lessa·S. L. A. de Queiroz
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Abstract

The statistics of critical spin-spin correlation functions in Ising systems with non-frustrated disorder are investigated on a strip geometry, via numerical transfer-matrix techniques. Conformal invariance concepts are used, in order to test for logarithmic corrections to pure power-law decay against distance. Fits of our data to conformal-invariance expressions, specific to logarithmic corrections to correlations on strips, give results with the correct sign, for the moments of order $n=0-4$ of the correlation-function distribution. We find an interval of disorder strength along which corrections to pure-system behavior can be decomposed into the product of a known $n$-dependent factor and an approximately $n$-independent one, in accordance with predictions. A phenomenological fitting procedure is proposed, which takes partial account of subdominant terms of correlation-function decay on strips. In the low-disorder limit, it gives results in fairly good agreement with theoretical predictions, provided that an additional assumption is made.

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Jean C. Lessa, S. L. A. de Queiroz. 2006-07-18. Logarithmic corrections to correlation decay in two-dimensional random-bond Ising systems. https://doi.org/10.1103/physreve.74.021114

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