English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/95107
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:


Time-dependent exchange-correlation functional for a Hubbard dimer: Quantifying nonadiabatic effects

AuthorsFuks, Johanna I.; Farzanehpour, Mehdi; Tokatly, I. V. ; Appel, H.; Kurth, S.; Rubio, Angel
Issue DateDec-2013
PublisherAmerican Physical Society
CitationPhysical Review A 88: 062512 (2013)
AbstractWe address and quantify the role of nonadiabaticity (“memory effects”) in the exchange-correlation (xc) functional of time-dependent density functional theory (TDDFT) for describing nonlinear dynamics of many-body systems. Time-dependent resonant processes are particularly challenging for available TDDFT approximations, due to their strong nonlinear and nonadiabatic character. None of the known approximate density functionals are able to cope with this class of problems in a satisfactory manner. In this work we look at the prototypical example of the resonant processes by considering Rabi oscillations within the exactly soluble two-site Hubbard model. We construct the exact adiabatic xc functional and show that (i) it does not reproduce correctly resonant Rabi dynamics, and (ii) there is a sizable nonadiabatic contribution to the exact xc potential, which turns out to be small only at the beginning and at the end of the Rabi cycle when the ground-state population is dominant. We then propose a “two-level” approximation for the time-dependent xc potential which can capture Rabi dynamics in the two-site problem. It works well both for resonant and for detuned Rabi oscillations and becomes essentially exact in the linear response regime.
Publisher version (URL)http://dx.doi.org/10.1103/PhysRevA.88.062512
Appears in Collections:(CFM) Artículos
Files in This Item:
File Description SizeFormat 
Time-dependent exchange-correlation.pdf534,41 kBAdobe PDFThumbnail
Show full item record
Review this work

Related articles:

WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.