Berlin 2018 – wissenschaftliches Programm
DY 55.3: Vortrag
Donnerstag, 15. März 2018, 10:30–10:45, EB 107
Transient dynamics in an excitonic insulator: Fast computation of nonequilibrium Green's functions — •Riku Tuovinen1, Denis Golež2, Michael Schüler2, Martin Eckstein3, and Michael Sentef1 — 1Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany — 2Department of Physics, University of Fribourg, 1700 Fribourg, Switzerland — 3Department of Physics, University of Erlangen-Nürnberg, 91058 Erlangen, Germany
A standard approach to nonequilibrium many-body problems is the Keldysh Green's function technique . Information about the studied system, e.g. photoemission spectra etc., is encoded into the Green's function. To access this, we have to consider coupled integro-differential equations (Kadanoff-Baym equations), whose efficient solution is not trivial . The Generalized Kadanoff-Baym Ansatz (GKBA) offers a simplification by decomposing the two-time-propagation of the Green's function into the time-propagation of a time-local density matrix . We discuss the time-propagation method à la GKBA and present some benchmark simulations against the full solution of the Kadanoff-Baym equations, concentrating on a simple model for an excitonic insulator . We investigate the dynamics of competing orders and how the balance between them could be controlled by laser driving.
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