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arXiv:cond-mat/0212326 · Journal of Mathematical Physics

A direct calculation of the free energy from the Bethe ansatz equation for the Heisenberg model

Go Kato, Miki Wadati

Published Aug 21, 2003• 0 citations
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Abstract

Thermodynamics of the XXX Heisenberg model is studied. The trace of the Boltzmann weight with respect to the Hilbert space is taken in the thermodynamic limit with the number of up-spins being fixed. The expression of the trace gives an explanation why the correct thermodynamic quantities are derived from the string hypothesis. A combination of this with the previous result leads to a conclusion that the free energy can be calculated only from the Bethe ansatz equation. The method is more direct than other known methods which were used to derive the free energy.

DOI
10.1063/1.1592610

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