Dynamics of N-spins Quantum Ferromagnet with Uniform Exchange: Exact Solution

M. Chertkov; I. Kolokolov

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Dynamics of N-spins Quantum Ferromagnet with Uniform Exchange: Exact Solution

M. Chertkov·I. Kolokolov

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Abstract

The transverse spin autocorrelation function at an arbitrary temperature are calculated rigorously for the system of $N$ uniformly exchanged quantum spins. At large $N$ the correlator in the para-phase is found to have a Gaussian bump at small times and a non vanishing tail at large times. A possible application of those exact results as forming a starting dynamical mean-field approximation for long-range quantum magnets and an accompanied physical picture are discussed.

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M. Chertkov, I. Kolokolov. 1994-04-28. Dynamics of N-spins Quantum Ferromagnet with Uniform Exchange: Exact Solution. https://arxiv.org/abs/cond-mat/9404093

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