Benchmarking nonequilibrium Green’s functions against configuration interaction for time-dependent Auger decay processes

We have recently proposed a nonequilibrium Green’s function (NEGF) approach to include Auger decay processes in the ultrafast charge dynamics of photoionized molecules. Within the so-called generalized Kadanoff–Baym ansatz the fundamental unknowns of the NEGF equations are the reduced one-particle d...

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Bibliographic Details
Published in:The European physical journal. B, Condensed matter physics Condensed matter physics, 2018, Vol.91 (10), Article 216
Main Authors: Covito, Fabio, Perfetto, Enrico, Rubio, Angel, Stefanucci, Gianluca
Format: Article
Language:English
Subjects:
Augers
Benchmarks
Complex Systems
Condensed Matter Physics
Configuration interaction
Decay
Electrons
Fluid- and Aerodynamics
Occupations
One dimensional models
Particle density (concentration)
Photoionization
Physics
Physics and Astronomy
Regular Article
Solid State Physics
Time dependence
Time functions
Topical issue: Special issue in honor of Hardy Gross
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Summary:We have recently proposed a nonequilibrium Green’s function (NEGF) approach to include Auger decay processes in the ultrafast charge dynamics of photoionized molecules. Within the so-called generalized Kadanoff–Baym ansatz the fundamental unknowns of the NEGF equations are the reduced one-particle density matrix of bound electrons and the occupations of the continuum states. Both unknowns are one-time functions like the density in time-dependent functional theory (TDDFT). In this work, we assess the accuracy of the approach against configuration interaction (CI) calculations in one-dimensional model systems. Our results show that NEGF correctly captures qualitative and quantitative features of the relaxation dynamics provided that the energy of the Auger electron is much larger than the Coulomb repulsion between two holes in the valence shells. For the accuracy of the results dynamical electron-electron correlations or, equivalently, memory effects play a pivotal role. The combination of our NEGF approach with the Sham–Schlüter equation may provide useful insights for the development of TDDFT exchange-correlation potentials with a history dependence.
ISSN:1434-6028
1434-6036
DOI:10.1140/epjb/e2018-90161-2