6533b820fe1ef96bd127a557
RESEARCH PRODUCT
Ultra-nonlocality in density functional theory for photo-emission spectroscopy.
Gianluca StefanucciA.-m. UimonenR. Van Leeuwensubject
Electromagnetic fieldPhysicsCondensed Matter - Materials Scienceta114Condensed Matter - Mesoscale and Nanoscale Physicsphotocurrentsphotoelectron spectroscopyGeneral Physics and AstronomyMaterials Science (cond-mat.mtrl-sci)FOS: Physical sciencesKinetic energySettore FIS/03 - Fisica della MateriaQuantum nonlocalitykineticsQuantum electrodynamicsKernel (statistics)Mesoscale and Nanoscale Physics (cond-mat.mes-hall)Density functional theoryEmission spectrumPhysical and Theoretical ChemistryPerturbation theorySpectroscopydescription
We derive an exact expression for the photo-current of photo-emission spectroscopy using time-dependent current density functional theory (TDCDFT). This expression is given as an integral over the Kohn-Sham spectral function renormalized by effective potentials that depend on the exchange-correlation kernel of current density functional theory. We analyze in detail the physical content of this expression by making a connection between the density-functional expression and the diagrammatic expansion of the photo-current within many-body perturbation theory. We further demonstrate that the density functional expression does not provide us with information on the kinetic energy distribution of the photo-electrons. Such information can, in principle, be obtained from TDCDFT by exactly modeling the experiment in which the photo-current is split into energy contributions by means of an external electromagnetic field outside the sample, as is done in standard detectors. We find, however, that this procedure produces very nonlocal correlations between the exchange-correlation fields in the sample and the detector.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2014-01-01 | The Journal of chemical physics |