Analytic response theory for the density matrix renormalization group

TL;DR

This paper introduces an analytic response theory for the density matrix renormalization group, enabling efficient calculation of response properties with improved accuracy, applicable to static and frequency-dependent phenomena.

Contribution

It develops and implements an analytic response framework for DMRG, enhancing the calculation of response properties compared to existing methods.

Findings

Accurately computes static and frequency-dependent polarizabilities.

Competitive with dynamical DMRG methods.

Improves accuracy with fewer DMRG states.

Abstract

We propose an analytic response theory for the density matrix renormalization group whereby response properties correspond to analytic derivatives of density matrix renormalization group observables with respect to the applied perturbations. Both static and frequency-dependent response theories are formulated and implemented. We evaluate our pilot implementation by calculating static and frequency dependent polarizabilities of short oligo-di-acetylenes. The analytic response theory is competitive with dynamical density matrix renormalization group methods and yields significantly improved accuracies when using a small number of density matrix renormalization group states. Strengths and weaknesses of the analytic approach are discussed.