Harnessing dressed time-dependent density functional theory for the non-perturbative regime: Electron dynamics with double excitations

TL;DR

This paper demonstrates that response-reformulated TDDFT with frequency-dependent kernels can accurately model non-perturbative electron dynamics involving double excitations, expanding its applicability beyond perturbative regimes.

Contribution

It shows how RR-TDDFT enables the use of exchange-correlation functionals developed for response regimes to accurately simulate strong-field, non-perturbative electron dynamics.

Findings

RR-TDDFT captures strong-field dynamics with double excitations.

Frequency-dependent kernels improve non-perturbative regime modeling.

Broader application of exchange-correlation functionals in non-linear regimes.

Abstract

Recent progress has been made in capturing spectral features of electronic states of double-excitation character in time-dependent density functional theory (TDDFT) through a frequency-dependent kernel. While it might appear that this development is limited to the perturbative regime, we show that when used within response-reformulated TDDFT, it accurately captures strong-field dynamics involving states of double-excitation character. More generally, this demonstrates how RR-TDDFT enables exchange-correlation functional developments in the response regime, which have so far been more successful than those in the non-linear regime, to be exploited for non-perturbative dynamics, thus significantly broadening their range of applications.