Regensburg 2022 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 30: Superconductivity: Poster Session
TT 30.13: Poster
Thursday, September 8, 2022, 15:00–18:00, P1
Tunable superconducting single electron transistors: from weak to strong-coupling regime — •Oliver Irtenkauf1, Laura Sobral-Rey1, David Ohnmacht1, Wolfgang Belzig1, Jens Siewert2, and Elke Scheer1 — 1Univ. Konstanz — 2Univ. del Pais Basque, Bilbao, Spain
An island coupled to two leads and a gate forms a single electron transistor (SET) that shows Coulomb blockade (CB). All-superconducting SETs have shown to enable a multitude of possible charge transport processes, not all of them are well understood [1], in particular in the strong-coupling regime [2]. The conceptually simpler SSN-SET reduces the number of possible processes. We study a device consisting of a S island coupled to a N lead via an oxide tunnel barrier, and to a S lead with a mechanically controlled break junction (MCBJ). Via the MCBJ, different coupling regimes can be studied from a tunnel contact to a point contact [2]. For weak coupling, our experimental findings in the N state can be understood in terms of the Orthodox Theory of CB [3,4]. For stronger coupling, we observe Andreev and Josephson transport as well as, in the N state, a renormalization of the charging energy [5,6]. We describe our experimental results in the S state with simulations based on a generalized master equation approach [7].
[1] J.M. Hergenrother et al., PRL 72, 1742 (1994)
[2] T. Lorenz et al., JLTP 191, 301 (2017)
[3] D. V. Averin, K. K. Likharev, JLTP 62, 345 (1986)
[4] H. Grabert, M. H. Devoret, NATO Sci. Ser. B, 294 (1992)
[5] P. Joyez et al., PRL 79, 1349 (1997)
[6] S. Jezouin et al., Nature 536, 58 (2016)
[7] J. Siewert, G. Schön, PRB 54, 7421 (1996)