Nonadiabatic Exchange-Correlation Kernel For Strongly Correlated Materials

Keywords

strongly correlated materials; time-dependent density-functional theory; ultrafast dynamics

Abstract

We formulate a rigorous method for calculating a nonadiabatic (frequency-dependent) exchange-correlation (XC) kernel appropriate for accurate description of both equilibrium and nonequilibrium properties of strongly correlated systems within the time-dependent density functional theory (TDDFT) via the charge susceptibility, which is in turn obtained from dynamical mean field theory (DMFT) based on the effective multi-orbital Hubbard model. Application to the simple case of the one-orbital Hubbard model already shows the importance of the nonadiabatic kernel as it leads to significant modification of the excitation spectrum - shifting the (adiabatic) peak and disclosing another that is reminiscent of the solution from DMFT. The impact of dynamical effects, naturally included through the nonadiabaticity of the XC kernel, becomes even more transparent in our consideration of the nonequilibrium charge-density response of a multi-orbital perovskite, YTiO3, to a perturbation by a femtosecond (fs) laser pulse. These initial results indicate that electron-electron correlations and nonadiabatic features may significantly affect the spectrum and nonequilibrium properties of strongly correlated systems. We also propose an algorithm for extension of the approach to non-linear response. The transparency and computational efficiency of this non-adiabatic TDDFT+DMFT approach opens the door to examination of the spectra and response of multi-orbital systems with many nonequivalent atoms - bulk material, films and nanostructures.

Publication Date

10-12-2017

Publication Title

Journal of Physics Condensed Matter

Volume

29

Issue

45

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1088/1361-648X/aa8ac1

Socpus ID

85037740784 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/85037740784

This document is currently not available here.

Share

COinS