%0 Conference Paper
%A Behner, Gerrit
%A Jalil, Abdur Rehman
%A Grützmacher, Detlev
%A Schäpers, Thomas
%T Superconducting diode effect in Josephson junctions based on topological insulator nanoribbons
%M FZJ-2026-01361
%D 2025
%X Recently, the superconducting diode effect has attracted a lot of attention [1]. A characteristic of the diode effect is that the magnitude of the critical supercurrent depends on the direction in which the current is driven. The Josephson diode effect occurs when both inversion and time-reversal symmetry are broken. For Josephson junctions with a semiconducting [2] or topological insulator [3] weak link, this can be accomplished by the presence of spin-orbit coupling in conjunction with an external magnetic field for the time-reversal symmetry breaking. Recently, the device layout asymmetry in a multi-terminal Josephson junction also led to a diode effect, either by keeping one of the superconducting electrodes floating [4,5] or by phase biasing the respective junctions [6]. We present measurements in both two- and multi-terminal Josephson junctions that clearly demonstrate the Josephson diode effect and underline the high quality of the devices fabricated. The fabrication is based on a combination of selective-area growth of the ternary topological insulator Bi0.8 Sb1.2 Te3 and shadow mask evaporation of the parent superconductor Nb. For the multi-terminal junctions we map out the transport properties as a function of bias currents and prove the coupling of the junctions by the observation of the multi-terminal geometry induced Josephson diode effect. The experimental findings are supported by simulations based on the resistively and capacitively shunted junction network model [4]. Regarding the single junction a pronounced Josephson diode effect is observed when an in-plane magnetic field is applied perpendicular to the junction current. Our analysis of the temperature dependence of the critical current indicates that the supercurrent is largely carried by topological surface states which in turn are responsible for the Josephson diode effect.[1] M. Nadeem, M.S. Fuhrer and X. Wang, Nature Reviews Physics 10, 558-577 (2023) [2] C. Baumgartner, L. Fuchs, A. Costa et al., Nature Nanotechnology 1, 39-44 (2022). [3] B. Lu, S. Ikegaya, P. Burset, Y. Tanaka and N. Nagaosa, Phys. Rev. Lett. 131, 096001 (2023) [4] M. Gupta, G. Graziano, M. Pendharkar, J. Dong, C. Dempsey, C. Palmström, V. Pribiag, Nature Communications, 14, 2041-1723 (2023) [5] G. Behner, A. R. Jalil, A. Rupp, H. Lüth, D. Grützmacher, Th. Schäpers, ACS Nano, accepted, 2025, arXiv:2410.19311 [6] M. Coraiola, A. Svetogorov, D. Haxell et al., ACS Nano, 18, 9221-9231 (2024)
%B Mallorca Topological Quantum Matter
%C 6 May 2025 - 9 May 2025, Palma de Mallorca (Spain)
Y2 6 May 2025 - 9 May 2025
M2 Palma de Mallorca, Spain
%F PUB:(DE-HGF)6
%9 Conference Presentation
%U https://juser.fz-juelich.de/record/1053017