Accurate computation of low-temperature thermodynamics for quantum spin chains

TL;DR

This paper demonstrates that the biorthonormal transfer-matrix renormalization group (BTMRG) method effectively computes low-temperature thermodynamics of quantum spin chains, surpassing traditional methods in accessing extremely low temperatures with high accuracy.

Contribution

The paper introduces the application of BTMRG to quantum spin chains, showing it outperforms conventional TMRG in low-temperature regimes and accurately calculates specific heat in frustrated chains.

Findings

BTMRG accesses lower temperatures than conventional TMRG.

BTMRG maintains high accuracy at low temperatures.

Successful calculation of specific heat for frustrated spin chains.

Abstract

We apply the biorthonormal transfer-matrix renormalization group (BTMRG) [Phys. Rev. E 83, 036702 (2011)] to study low-temperature properties of quantum spin chains. Simulation on isotropic Heisenberg spin-1/2 chain demonstrates that the BTMRG outperforms the conventional transfer-matrix renormalization group (TMRG) by successfully accessing far lower temperature unreachable by conventional TMRG, 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.