Finite-temperature dynamics with the density-matrix renormalization group method

TL;DR

This paper introduces a new numerical approach combining DMRG and Lanczos methods to compute finite-temperature dynamical responses in 1D strongly correlated systems, demonstrated on the Heisenberg chain.

Contribution

The paper presents a novel numerical technique that integrates DMRG with finite-temperature Lanczos diagonalization for improved dynamical response calculations.

Findings

Successfully applied to the anisotropic Heisenberg chain

Revealed nontrivial critical behavior in the isotropic case

Validated the method's feasibility for strongly correlated systems

Abstract

We present a novel numerical method for the evaluation of dynamical response functions at finite temperatures in one-dimensional strongly correlated systems. The approach is based on the density-matrix renormalization group method, combined with the finite-temperature Lanczos diagonalization. The feasibility of the method is tested on the example of dynamical spin correlations in the anisotropic Heisenberg chain, in particular it yields nontrivial results for the critical behavior in the isotropic case.