SKM 2021 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 9: Poster Session: Correlated Electrons
TT 9.37: Poster
Tuesday, September 28, 2021, 13:30–16:00, P
Electronic transport in molecular junctions: The generalized Kadanoff-Baym ansatz with initial contact and correlations — •Riku Tuovinen1, Robert van Leeuwen2, Enrico Perfetto3, and Gianluca Stefanucci3 — 1University of Helsinki, Finland — 2University of Jyväskylä, Finland — 3Università di Roma Tor Vergata, Italy
The generalized Kadanoff-Baym ansatz (GKBA) offers a computationally inexpensive approach to simulate out-of-equilibrium quantum systems within the framework of nonequilibrium Green’s functions. For finite systems, the limitation of neglecting initial correlations in
the conventional GKBA approach has recently been overcome [1]. However, in the context of quantum transport, the contacted nature of the initial state, i.e., a junction connected to bulk leads, requires a further extension of the GKBA approach. In this work, we lay down a GKBA scheme that includes initial correlations in a partition-free setting [2]. In practice, this means that the equilibration of the initially correlated and contacted molecular junction can be separated from the real-time evolution. The information about the contacted initial state is included in the out-of-equilibrium calculation via explicit evaluation of the memory integral for the embedding self-energy, which can be performed without affecting the computational scaling with the simulation time and system size. We demonstrate the developed method in carbon-based molecular junctions.
[1] D. Karlsson et al., Phys. Rev. B 98, 115148 (2018)
[2] R. Tuovinen et al., J. Chem. Phys. 154, 094104 (2021)