Within the nonequilibrium Green's function (NEGF) formalism, the generalized Kadanoff-Baym ansatz (GKBA) has stood out as a computationally cheap method to investigate the dynamics of interacting quantum systems driven out of equilibrium. Current implementations of the NEGF-GKBA, however, suffer from a drawback: real-time simulations require noncorrelated states as initial states. Consequently, initial correlations must be built up through an adiabatic switching of the interaction before turning on any external field, a procedure that can be numerically highly expensive. In this work, we extend the NEGF-GKBA to allow for correlated states as initial states. Our scheme makes it possible to efficiently separate the calculation of the initial state from the real-time simulation, thus paving the way for enlarging the class of systems and external drivings accessible by the already successful NEGF-GKBA. We demonstrate the accuracy of the method and its improved performance in a model donor-acceptor dyad driven out of equilibrium by an external laser pulse.

Karlsson, D., van Leeuwen, R., Perfetto, E., Stefanucci, G. (2018). The generalized Kadanoff-Baym ansatz with initial correlations. PHYSICAL REVIEW. B, 98(11) [10.1103/PhysRevB.98.115148].

The generalized Kadanoff-Baym ansatz with initial correlations

Perfetto E;Stefanucci G
2018-01-01

Abstract

Within the nonequilibrium Green's function (NEGF) formalism, the generalized Kadanoff-Baym ansatz (GKBA) has stood out as a computationally cheap method to investigate the dynamics of interacting quantum systems driven out of equilibrium. Current implementations of the NEGF-GKBA, however, suffer from a drawback: real-time simulations require noncorrelated states as initial states. Consequently, initial correlations must be built up through an adiabatic switching of the interaction before turning on any external field, a procedure that can be numerically highly expensive. In this work, we extend the NEGF-GKBA to allow for correlated states as initial states. Our scheme makes it possible to efficiently separate the calculation of the initial state from the real-time simulation, thus paving the way for enlarging the class of systems and external drivings accessible by the already successful NEGF-GKBA. We demonstrate the accuracy of the method and its improved performance in a model donor-acceptor dyad driven out of equilibrium by an external laser pulse.
2018
Pubblicato
Rilevanza internazionale
Articolo
Esperti anonimi
Settore FIS/03 - FISICA DELLA MATERIA
English
Karlsson, D., van Leeuwen, R., Perfetto, E., Stefanucci, G. (2018). The generalized Kadanoff-Baym ansatz with initial correlations. PHYSICAL REVIEW. B, 98(11) [10.1103/PhysRevB.98.115148].
Karlsson, D; van Leeuwen, R; Perfetto, E; Stefanucci, G
Articolo su rivista
File in questo prodotto:
File Dimensione Formato  
PR-B98-115148-2018.pdf

accesso aperto

Tipologia: Versione Editoriale (PDF)
Licenza: Copyright dell'editore
Dimensione 976.83 kB
Formato Adobe PDF
976.83 kB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/208825
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 31
  • ???jsp.display-item.citation.isi??? 31
social impact