Thermodynamics of the Anisotropic Heisenberg Chain Calculated by the Density Matrix Renormalization Group Method

Abstract

The density matrix renormalization group (DMRG) method is applied to the\nanisotropic Heisenberg chain at finite temperatures. The free energy of the\nsystem is obtained using the quantum transfer matrix which is iteratively\nenlarged in the imaginary time direction. The magnetic susceptibility and the\nspecific heat are calculated down to T=0.01J and compared with the Bethe ansatz\nresults. The agreement including the logarithmic correction in the magnetic\nsusceptibility at the isotropic point is fairly good.\n