Hannover 2020 – scientific programme
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A: Fachverband Atomphysik
A 9: Poster Session - Atomic Physics I
A 9.18: Poster
Monday, March 9, 2020, 16:00–18:00, Empore Lichthof
Fast Nonequilibrium Green functions calculations for atomic systems — •Maximilian Rodriguez Rasmussen, Niclas Schlünzen, Jan-Philip Joost, and Michael Bonitz — Christian-Albrechts-Universität zu Kiel, Kiel, Germany
The Nonequilibrium Green Functions formalism (NEGF) 1 is well suited to accurately describe the dynamics of correlated quantum systems. A main cause of practical limitation is the high computational effort, manifest in a T3 scaling with propagation time T. The scaling can be improved to T2 by introducing the Generalized-Kadanoff–Baym Ansatz (GKBA) 2. Its application to the description of atoms, where precise theoretical results on fast dynamical processes, such as laser excitations, are needed, is of particular interest 3,4. Recently the G1-G2 formalism 5 based on the GKBA was developed. With this method a dramatically improved scaling proportional to T can be achieved. Here first results for atomic systems are presented.
1 L. P. Kadanoff, G. Baym, Quantum Statistical Mechanics (1962)
2 P. Lipavský et al., Phys. Rev. B 34, 6933 (1986)
3 E. Perfetto et al., Phys. Rev. A 92, 3 (2015)
4 R. Tuovinen et al., The J. of Chem. Phys., 51, 17 (2019)
5 N. Schlünzenet al., submitted, arXiv:1909.11489 cond-mat.str-el