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We investigate dynamic correlation functions for a pair of exchange‐coupled classical spins with biaxial exchange and/or single‐site anisotropy. This represents a Hamiltonian system with two degrees of freedom for which we have previously established the integrability criteria. We discuss the impact of (non‐)integrability on the autocorrelation functions and their spectral properties. We point out the role of long‐time anomalies caused by low‐flux cantori, which dominate the convergence properties of time averages and determine the long‐time asymptotic behavior of autocorrelation functions in nonintegrable cases.

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Copyright 1988 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.

The following article appeared in Journal of Applied Physics and may be found at