Talk (non-conference) (Invited)

FZJ-2023-03640

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Phase-Coherent Transport in Multi-Terminal Topological Insulator-Based Nanostructures

Schäpers, T.FZJ*

2023

Abstract: Networks of three-dimensional nanoribbons of topological insulators (TI) in combination with superconducting electrodes are promising building blocks for topoelectronic applications and topological quantum computations. In our approach, these structures are fabricated by a dedicated fabrication method that uses selective-area growth in combination with in-situ shadow evaporation of the superconducting electrodes. On single straight TI nanoribbons and TI ring structures, we have found pronounced Aharonov-Bohm oscillations in magnetoresistance, indicating transport via topologically protected surface states [1,2,3]. In three-terminal TI nanoribbon T- and Y-junctions, a dependence of the current on the in-plane magnetic field has been observed, with the current in the surface states being clearly steered toward a preferred output at different magnetic field orientations. The origin of this steering effect is interpreted in terms of orbital effects in combination with spin-momentum locking [4]. In in-situ prepared superconductor-topological insulator nanoribbon Josephson junctions a pronounced supercurrent was observed [5]. For multi-terminal TI hybrid junction the interplay of the Josephson supercurrent in the different branches is investigated. Here, we found a clear coupling in the supercurrent between the different electrodes. Work done in collaboration with: D. Rosenbach, J. Kölzer, G. Behner, E. Zimmermann, J. Teller, A. Rupp, J. Karthein, A.R. Jalil, K. Moors, T.W. Schmitt, M. Schleenvoigt, M. Vaßen-Carl, G. Bihlmaier, H. Lüth, G. Mussler, P. Schüffelgen, D. Grützmacher.[1] J. Kölzer, et al., Nanotechnology 31, 325001 (2020).[2] D. Rosenbach, et al., Sci. Post. Phys. Core 5, 17 (2022).[3] G. Behner et al., Nano Letters, 23, 6347 (2023).[4] J. Kölzer, et al., Communications Materials 2, 1 (2021).[5] D. Rosenbach, et al., Science Advances 7, eabf1854 (2021).

Keyword(s): Information and Communication (1st) ; Condensed Matter Physics (2nd)

Note: This work was partly funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy - Cluster of Excellence Matter14and Light for Quantum Computing (ML4Q) EXC 2004/1 – 390534769. and by the Bavarian Ministry of Economic Affairs, Regional Development and Energy within Bavaria’s High-Tech Agenda Project "Bausteine für das Quantencomputing auf Basis topologischer Materialien mit experimentellen und theoretischen Ansätzen" (grant allocation no. 07 02/686 58/1/21 1/22 2/23)

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Contributing Institute(s):

1. Halbleiter-Nanoelektronik (PGI-9)

Research Program(s):

1. 5222 - Exploratory Qubits (POF4-522) (POF4-522)

Appears in the scientific report 2023

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