Regensburg 2022 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 29: Transport: Poster Session

TT 29.1: Poster

Thursday, September 8, 2022, 15:00–18:00, P1

Relaxation dynamics in two quantum dots coupled to the environment: The role of coupling asymmetry — •Lukas Litzba, Eric Kleinherbers, Nikodem Szpak, and Jürgen König — Fakultät für Physik, Universität Duisburg-Essen, Lotharstraße 1, 47057 Duisburg, Germany

We study a strongly interacting two-site Fermi-Hubbard model representing two coupled quantum dots and couple them each with different strengths to Markovian baths. We start with the Born-Redfield equation (without second Markov approximation) and approximate it by the coherent Lindblad master equations [1]. Using this technique we observe that the long-time dynamics of a quantum state, in particular the contribution from the energy coherences, depends strongly on the asymmetry between the bath coupling strengths of the dots. In contrast to the Born-Redfield equation and the coherent Lindblad master equations the popular secular approximation fails to properly describe the interdot and bath-dot currents in the asymmetric coupling case. To compare the quality of the approximations we use the exact solution in the case of no Coulomb interaction.

[1] E. Kleinherbers, N. Szpak, J. König, R. Schützhold, Phys. Rev. B 101, 125131 (2020)