SKM 2023 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 48: Topological Superconductors

TT 48.3: Vortrag

Donnerstag, 30. März 2023, 10:00–10:15, HSZ 304

Ground state topology of a multiterminal superconducting double quantum dot — •Lev Teshler, Hannes Weisbrich, and Wolfgang Belzig — Universität Konstanz, Konstanz, Germany

Multiterminal Josephson junctions can provide topological Andreev bound states in the space of the superconducting phases [1]. The topology of the Andreev bound states manifests itself in a quantized transconductance when applying voltages to two terminals. Such systems are candidates to realise higher-dimensional topology and non-Abelian Berry phases using their synthetic dimensions [2]. For practical purposes a linear arrangement of quantum dots coupled to superconductors might be beneficial and was shown to exhibit nontrivial topology [3]. In this work, we study a double quantum dot in which each dot is coupled to two superconductors. This system that depends on three superconducting phase differences already displays non-trivial topology in terms of the first Chern number and is an example that allows to study the fundamental properties of this class of systems. We will study the ground state and the respective topological phase diagram for different sets of parameters of the double quantum dot. Furthermore, we will also discuss the influence of Coulomb interaction and Zeeman splitting on the topological properties of the ground state.

[1] R.-P. Riwar et al., Nat. Commun. 7, 1 (2016)

[2] H. Weisbrich et al., PRX Quantum 2, 010310 (2021)

[3] R. Klees et al., Phys Rev B 103, 014516 (2021)