Accurate computation of low-temperature thermodynamics for quantum spin chains

Abstract

We apply the biorthonormal transfer-matrix renormalization group (BTMRG) to study low-temperature properties of quantum spin chains. Simulations on anisotropic Heisenberg spin-1/2 chains demonstrate that the BTMRG outperforms the conventional transfer-matrix renormalization group by successfully accessing far lower temperature than previously reported, while retaining the same level of accuracy. The power of the method is further illustrated by the calculation of the low-temperature specific heat for a frustrated spin chain. © 2012 American Physical Society.