Regensburg 2022 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 13: Quantum Dots, Quantum Wires, Point Contacts

TT 13.2: Vortrag

Dienstag, 6. September 2022, 09:45–10:00, H23

Pair-amplitude dynamics in superconductor-quantum dot hybrids — •Markus Heckschen and Björn Sothmann — Universität Duisburg-Essen, Duisburg, Deutschland

We consider a three-terminal system consisting of a quantum dot strongly coupled to two superconducting reservoirs in the infinite gap limit and weakly coupled to a normal metal. Using a real-time diagrammatic approach, we calculate the dynamics of the proximity-induced pair amplitude on the quantum dot. We find that after a quench the pair amplitude shows pronounced oscillations with a frequency determined by the coupling to the superconductors. In addition, it decays exponentially on a time scale set by the coupling to the normal metal. Strong oscillations of the pair amplitude occur also when the system is periodically driven both in the adiabatic and fast-driving limit. We relate the dynamics of the pair amplitude to the Josephson and Andreev current through the dot to demonstrate that it is an experimentally accessible quantity.

[1] M. Heckschen and B. Sothmann, Phys. Rev. B 105 (2022) 045420