Second order perturbation theory for a superconducting double quantum dot

0538692 - FZÚ 2021 RIV JP eng C - Conference Paper (international conference)
Pokorný, Vladislav - Žonda, M. - Loukeris, G. - Novotný, T.
Second order perturbation theory for a superconducting double quantum dot.
JPS Conference Proceedings. Vol. 30. Tokyo: Physical Society of Japan, 2020 - (Hotta, T.; Katsufuji, T.), s. 1-8, č. článku 011002. ISBN 978-4-89027-142-9. ISSN 2435-3892.
[International Conference on Strongly Correlated Electron Systems (SCES2019). Okayama (JP), 23.09.2020-28.09.2020]
R&D Projects: GA ČR GA19-13525S; GA MŠMT LTC19045
Institutional support: RVO:68378271
Keywords : superconducting quantum dots * diagrammatic perturbation theory * Andreev bound states
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)

We extend our approach based on the second order perturbation theory in the Coulomb interaction recently developed for quantum dots coupled to superconducting leads to the superconducting double quantum dot setups. Using our perturbative method we evaluate several single-particle quantities such as on-dot induced gap and generalized occupations together with the Andreev in-gap spectra and compare them with numerically exact results from the Numerical Renormalization Group and Quantum Monte Carlo finding a very good correspondence for not too strongly correlated regimes. Thus we can offer in a wide parameter range this method as an efficient and reliable alternative to the heavy numerical tools exclusively used so far for the description of such experimentally relevant systems.

Permanent Link: http://hdl.handle.net/11104/0316440