Thermodynamics of frustrated quantum spin chains

TL;DR

This paper demonstrates that transfer matrix DMRG effectively computes thermodynamic properties of frustrated quantum spin chains at very low temperatures, overcoming limitations of traditional methods.

Contribution

The authors introduce and validate transfer matrix DMRG as a powerful new approach for studying thermodynamics in frustrated quantum spin systems.

Findings

Accurate thermodynamic data down to T=0.025 for frustrated chains.

Elimination of incommensurability and sign problems in simulations.

Demonstrated superiority over existing methods for these systems.

Abstract

We apply the transfer matrix DMRG to frustrated quantum spin chains, going down to T=0.025 while being in the thermodynamic limit. The incommensurability problem of exact diagonalization and the negative sign problem of quantum Monte Carlo vanish completely. To illustrate the method, we give results for chains with next-nearest neighbor frustration and the delta chain, which has been a testbed for many thermodynamic methods. By comparison, the DMRG proves to be an extremely powerful method for the old problem of the thermodynamics of frustrated systems.