Dresden 2020 – wissenschaftliches Programm
Die DPG-Frühjahrstagung in Dresden musste abgesagt werden! Lesen Sie mehr ...
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 33: Correlated Electrons: Method Development 1
TT 33.9: Vortrag
Mittwoch, 18. März 2020, 11:45–12:00, HSZ 201
Quantum Dynamics Made Fast: Achieving Linear Time-Scaling for Nonequilibrium Green Functions — •Niclas Schlünzen, Jan-Philip Joost, and Michael Bonitz — CAU Kiel, Germany
The accurate description of nonequilibrium dynamics in correlated quantum-many-body systems remains to be a driving force for current research in condensed-matter physics and beyond. Among others, the nonequilibrium Green functions (NEGF) method has proven to be a powerful tool to predict quantum dynamics[1]. However, NEGF simulations are computationally expensive due to their T3 scaling with the simulation duration T . With the introduction of the generalized Kadanoff–Baym ansatz[2] (GKBA), T2 scaling could be achieved for second order Born (SOA) selfenergies[3], which has substantially extended the scope of NEGF simulations. Recently[4], we could show that GKBA-NEGF simulations can be performed with order T1 scaling for SOA and even GW selfenergies. Here, we show numerical results for various many-body approximations and demonstrate that tremendous computational speed-up can be achieved.
[1] K. Balzer and M. Bonitz, Lect. Notes Phys. 867 (2013)
[2] P. Lipavský et al., Phys. Rev. B 34, 6933 (1986)
[3] S. Hermanns et al., Phys. Scr. 2012 014036 (2012)
[4] N. Schlünzen et al., submitted, arXiv:1909.11489