Density-matrix spectra for integrable models

TL;DR

This paper analytically derives the density-matrix spectra for integrable quantum chains using corner transfer matrices, explaining their exponential behavior observed in numerical DMRG calculations.

Contribution

It provides an analytical method to obtain density-matrix spectra for integrable models, linking corner transfer matrices to DMRG results.

Findings

Spectra can be derived analytically for integrable models.

Spectra exhibit exponential character in these cases.

Method applied to transverse Ising and XXZ Heisenberg models.

Abstract

The spectra which occur in numerical density-matrix renormalization group (DMRG) calculations for quantum chains can be obtained analytically for integrable models via corner transfer matrices. This is shown in detail for the transverse Ising chain and the uniaxial XXZ Heisenberg model and explains in particular their exponential character in these cases.