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RESEARCH PRODUCT

Comparative study of many-body perturbation theory and time-dependent density functional theory in the out-of-equilibrium Anderson model

Elham KhosraviElham KhosraviE. K. U. GrossE. K. U. GrossR. Van LeeuwenR. Van LeeuwenAdrian StanAdrian StanA.-m. UimonenA.-m. UimonenStefan KurthStefan KurthStefan KurthGianluca StefanucciGianluca Stefanucci

subject

PhysicsCondensed Matter - Mesoscale and Nanoscale Physicsta114Non-equilibrium thermodynamicsFOS: Physical sciences02 engineering and technologyTime-dependent density functional theory021001 nanoscience & nanotechnologyCondensed Matter Physics01 natural sciencesMany bodySettore FIS/03 - Fisica della MateriaElectronic Optical and Magnetic MaterialsCondensed Matter - Other Condensed MatterQuantum mechanicsQuantum electrodynamics0103 physical sciencesMesoscale and Nanoscale Physics (cond-mat.mes-hall)Local-density approximationPerturbation theory010306 general physics0210 nano-technologyAdiabatic processAnderson impurity modelOther Condensed Matter (cond-mat.other)

description

We study time-dependent electron transport through an Anderson model. The electronic interactions on the impurity site are included via the self-energy approximations at Hartree-Fock (HF), second Born (2B), GW, and T-matrix levels as well as within a time-dependent density functional (TDDFT) scheme based on the adiabatic Bethe-ansatz local density approximation (ABALDA) for the exchange-correlation potential. The Anderson model is driven out of equilibrium by applying a bias to the leads, and its nonequilibrium dynamics is determined by real-time propagation. The time-dependent currents and densities are compared to benchmark results obtained with the time-dependent density matrix renormalization group (tDMRG) method. Many-body perturbation theory beyond HF gives results in close agreement with tDMRG, especially within the 2B approximation. We find that the TDDFT approach with the ABALDA approximation produces accurate results for the densities on the impurity site, but overestimates the currents. This problem is found to have its origin in an overestimation of the lead densities, which indicates that the exchange-correlation potential must attain nonzero values in the leads. © 2011 American Physical Society.

yearjournalcountryeditionlanguage
2011-01-01
https://dx.doi.org/10.48550/arxiv.1107.0162