arXiv:2105.01352 · Journal of High Energy Physics

T − W relation and free energy of the Heisenberg chain at a finite temperature

Pengcheng Lu, Yi Qiao, Junpeng Cao, Wen‐Li Yang, Kangjie Shi, Yupeng Wang

Published Jul 20, 2021• 2 citations

Abstract

Abstract A new nonlinear integral equation (NLIE) describing the thermodynamics of the Heisenberg spin chain is derived based on the t − W relation of the quantum transfer matrices. The free energy of the system in a magnetic field is thus obtained by solving the NLIE. This method can be generalized to other lattice quantum integrable models. Taking the SU(3)-invariant quantum spin chain as an example, we construct the corre- sponding NLIEs and compute the free energy. The present results coincide exactly with those obtained via other methods previously.

DOI: 10.1007/jhep07(2021)133

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