• DOI:10.1038/ncomms10303
• Corpus ID: 2842670

4π-periodic Josephson supercurrent in HgTe-based topological Josephson junctions

@article{Wiedenmann20164periodicJS,
  title={4$\pi$-periodic Josephson supercurrent in HgTe-based topological Josephson junctions},
  author={Jonas Wiedenmann and Erwann Bocquillon and Russell S. Deacon and Simon Hartinger and O. Herrmann and Teun M. Klapwijk and Luis Maier and Christopher P. Ames and Christoph Br{\"u}ne and Charles Gould and Akira Oiwa and Koji Ishibashi and Seigo Tarucha and Hartmut Buhmann and Laurens W. Molenkamp},
  journal={Nature Communications},
  year={2016},
  volume={7}
}

• J. Wiedenmann, E. Bocquillon, +12 authors L. Molenkamp
• Published 18 March 2015
• Physics
• Nature Communications

The Josephson effect describes the generic appearance of a supercurrent in a weak link between two superconductors. Its exact physical nature deeply influences the properties of the supercurrent. In recent years, considerable efforts have focused on the coupling of superconductors to the surface states of a three-dimensional topological insulator. In such a material, an unconventional induced p-wave superconductivity should occur, with a doublet of topologically protected gapless Andreev bound states, whose energies vary 4π-periodically with the superconducting phase difference across the junction. In this article, we report the observation of an anomalous response to rf irradiation in a Josephson junction made of a HgTe weak link. The response is understood as due to a 4π-periodic contribution to the supercurrent, and its amplitude is compatible with the expected contribution of a gapless Andreev doublet. Our work opens the way to more elaborate experiments to investigate the induced superconductivity in a three-dimensional insulator.