Breakthrough in Nanotechnology: Researchers Develop Tunable Superconducting Diode Effect in Topological Nano-squid

Strategic Insights -

Researchers at the University of Cologne have made a significant discovery in the field of nanotechnology, developing a tunable superconducting diode effect in a topological nano-squid. This breakthrough has far-reaching implications for the development of emerging technologies, particularly in the field of nanowires. The research, funded by the European Research Council, German Research Foundation, and other organizations, demonstrates a new approach to harnessing the potential of topological superconductivity.

Key Takeaways:

  • The researchers developed a device consisting of a topological-insulator (TI) nanowire side-contacted by superconductors to form a lateral Josephson junction, which presents a large diode effect with an efficiency of 0.3 when a parallel magnetic field is applied.
  • The sign and magnitude of the diode effect are tunable not only by the magnetic field but also by the back-gate voltage.
  • The diode effect can be understood by modeling the system as a nano-superconducting quantum interference device (SQUID), in which the top and bottom surfaces of the TI nanowire each form a line junction.
  • The observed diode effect marks the emergence of topological superconductivity in TI nanowire-based Josephson junctions.
  • The research was funded by the European Research Council, German Research Foundation, Studienstiftung des deutschen Volkes, German Research Foundation under the Walter Benjamin program, and Simons Foundation.
  • The study included a team of researchers led by Yoichi Ando, with contributions from Ella Nikodem, Jakob Schluck, Junya Feng, Mahasweta Bagchi, Max Geier, Liang Fu, Michal Papaj, and Henry F. Legg.

Statistics:

  • The diode effect efficiency reaches 0.3 when a parallel magnetic field is applied (Science Advances, 2025;11(38)).
  • The sign and magnitude of the diode effect are tunable by the back-gate voltage (Science Advances, 2025;11(38)).
  • The device consists of a TI nanowire side-contacted by superconductors to form a lateral Josephson junction (Science Advances, 2025;11(38)).

Sources:

  • Science Advances. "Tunable Superconducting Diode Effect In a Topological Nano-squid." Science Advances, 2025;11(38).
  • NewsRx. "Researchers' Work from University of Cologne Focuses on Nanowires (Tunable Superconducting Diode Effect In a Topological Nano-squid)." Nanotechnology Weekly. October 20, 2025; p 1957.