Accurate Relativistic Real-Time Time-Dependent Density Functional Theory for Valence and Core Attosecond Transient Absorption Spectroscopy

Abstract

First principle theoretical modeling of out-of-equilibrium processes observed in attosecond pump-probe transient absorption spectroscopy (TAS) triggering pure electron dynamics remains a challenging task, specially for heavy elements and/or core excitations containing fingerprints of scalar and spin-orbit relativistic effects. To address this, we formulate a methodology for simulating TAS within the relativistic real-time time-dependent density functional theory (RT-TDDFT) framework, for both the valence and core energy regime. Especially for TAS, full four-component (4c) RT simulations are feasible but computationally demanding. Therefore, in addition to the 4c approach, we also introduce the atomic mean-field exact two-component (amfX2C) Hamiltonian accounting for one- and two-electron picture-change corrections within RT-TDDFT. amfX2C preserves the accuracy of the parent 4c method at a fraction of its computational cost. Finally, we apply the methodology to study valence and near L${}_{2,3}$-edge TAS processes of experimentally relevant systems and provide additional physical insights using relativistic non-equilibrium response theory.

References in corpus (7)

• Simulating pump-probe photo-electron and absorption spectroscopy on the attosecond time-scale with time-dependent density-functional theory
• Time-resolved spectroscopy in time dependent density functional theory: An exact condition
• Non-linear phenomena in time-dependent density-functional theory: What Rabi physics can teach us
• Exact two-component Hamiltonians for relativistic quantum chemistry: Two-electron picture-change corrections made simple
• Some Exact Properties of the Nonequilibrium Response Function for Transient Photoabsorption
• Time-dependent coupled cluster theory for ultrafast transient absorption spectroscopy
• Exact two-component TDDFT with simple two-electron picture-change corrections: X-ray absorption spectra near L- and M-edges of four-component quality at two-component cost

Cited by in corpus (8)

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• Towards accurate spin-orbit splittings from relativistic multireference electronic structure theory
• Generalization of one-center non orthogonal configuration interaction singles to open shell singlet reference states: Theory and application to valence-core pump-probe states in acetylacetone
• Cost-Efficient High-Resolution Linear Absorption Spectra Through Extrapolating the Dipole Moment from Real-Time Time-Dependent Electronic-Structure Theory
• Time-Dependent Equation-of-Motion Coupled-Cluster Simulations with a Defective Hamiltonian
• Topological phase transitions via attosecond x-ray absorption spectroscopy
• First-principles approach to ultrafast pump-probe spectroscopy in solids