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@INPROCEEDINGS{Behner:1053017,
      author       = {Behner, Gerrit and Jalil, Abdur Rehman and Grützmacher,
                      Detlev and Schäpers, Thomas},
      title        = {{S}uperconducting diode effect in {J}osephson junctions
                      based on topological insulator nanoribbons},
      reportid     = {FZJ-2026-01361},
      year         = {2025},
      abstract     = {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)},
      month         = {May},
      date          = {2025-05-06},
      organization  = {Mallorca Topological Quantum Matter,
                       Palma de Mallorca (Spain), 6 May 2025 -
                       9 May 2025},
      subtyp        = {Invited},
      cin          = {PGI-9},
      cid          = {I:(DE-Juel1)PGI-9-20110106},
      pnm          = {5222 - Exploratory Qubits (POF4-522) / DFG project
                      G:(GEPRIS)491798118 - Magnetische topologische Isolatoren
                      für robuste Majorana Zustände (491798118) / DFG project
                      G:(GEPRIS)390534769 - EXC 2004: Materie und Licht für
                      Quanteninformation (ML4Q) (390534769)},
      pid          = {G:(DE-HGF)POF4-5222 / G:(GEPRIS)491798118 /
                      G:(GEPRIS)390534769},
      typ          = {PUB:(DE-HGF)6},
      url          = {https://juser.fz-juelich.de/record/1053017},
}