Fast Nonequilibrium Green Functions simulations with GW selfenergies
ORAL
Abstract
Quantum kinetic approaches [1] have proven successful in describing dynamics of the uniform electron gas. The Nonequilibrium Green Functions (NEGF) method is a powerful tool to compute time-dependent expectation values of single-particle observables in correlated quantum many-body-systems. Its unfavorable Nt3 scaling with propagation time Nt could be reduced to Nt2 by introduction of the Generalized Kadanoff-Baym Ansatz (GKBA)[2]. Recently, an exact time-local (Nt1) reformulation of the GKBA, the G1–G2 scheme [3,4], has been found for various self energies, which makes this method viable for long time simulations.
In the Jellium basis the G1–G2 scheme has an especially advantageous CPU time scaling of Nb3Nt1 for both second-order and GW selfenergies, which makes this approach particularly interesting for this system. Furthermore, its derivation gives rise to an alternative way to compute the nonequilibrium screened potential. Here, we present first relaxation results in 1 and 2 dimensions.
[1] M. Bonitz, Quantum Kinetic Theory (Springer, 2016)
[2] P. Lipavský, V. Špička, B. Velický, Phys. Rev. B34, 6933 (1986)
[3] N. Schlünzen, J.-P. Joost, M. Bonitz, Phys. Rev. Lett. 124, 076601 (2020)
[4] J.-P. Joost, N. Schlünzen, M. Bonitz, Phys. Rev. B 101, 245101 (2020)
In the Jellium basis the G1–G2 scheme has an especially advantageous CPU time scaling of Nb3Nt1 for both second-order and GW selfenergies, which makes this approach particularly interesting for this system. Furthermore, its derivation gives rise to an alternative way to compute the nonequilibrium screened potential. Here, we present first relaxation results in 1 and 2 dimensions.
[1] M. Bonitz, Quantum Kinetic Theory (Springer, 2016)
[2] P. Lipavský, V. Špička, B. Velický, Phys. Rev. B34, 6933 (1986)
[3] N. Schlünzen, J.-P. Joost, M. Bonitz, Phys. Rev. Lett. 124, 076601 (2020)
[4] J.-P. Joost, N. Schlünzen, M. Bonitz, Phys. Rev. B 101, 245101 (2020)
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Presenters
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Christopher Makait
Univ Kiel
Authors
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Christopher Makait
Univ Kiel
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Niclas Schlünzen
ITAP, University of Kiel, University of Kiel, Institute of Theoretical Physics and Astrophysics, Kiel University, Germany, Univ Kiel, CAU Kiel, Germany
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Jan-Philip Joost
ITAP, University of Kiel, University of Kiel, Institute of Theoretical Physics and Astrophysics, Kiel University, Germany, Univ Kiel, CAU Kiel, Germany
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Michael Bonitz
Kiel University, ITAP, University of Kiel, University of Kiel, Institute of Theoretical Physics and Astrophysics, Kiel University, Germany, Institut für Theoretische Physik und Astrophysik, Christian-Albrechts-Universität zu Kiel, Univ Kiel, CAU Kiel, Germany