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}
}
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… 
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References

SHOWING 1-10 OF 68 REFERENCES
Josephson supercurrent through a topological insulator surface state.
TLDR
Direct evidence for Josephson supercurrents in superconductor (Nb)-topological insulator (Bi(2)Te(3))-superconductor electron-beam fabricated junctions is provided by the observation of clear Shapiro steps under microwave irradiation, and a Fraunhofer-type dependence of the critical current on magnetic field.
Helical Andreev bound states and superconducting Klein tunneling in topological insulator Josephson junctions
Currently, much effort is being put into detecting unconventional p-wave superconductivity in Josephson junctions based on topological insulators (TIs). For that purpose we propose to use
Josephson Supercurrent through the Topological Surface States of Strained Bulk HgTe
enable a study of transport through its unconventional surface states without being hindered by a parallel bulk conductance. Here, we show transport experiments on HgTe-based Josephson junctions to
On the possibility of the fractional ac Josephson eect in non-topological conventional superconductor-normal-superconductor junctions
Topological superconductors supporting Majorana Fermions with non-abelian statistics are presently a subject of intense theoretical and experimental effort. It has been proposed that the observation
Dynamical gate-tunable supercurrents in topological Josephson junctions
Josephson junctions made of closely-spaced conventional superconductors on the surface of 3D topological insulators have been proposed to host Andreev bound states (ABSs) which can include Majorana
Nonequilibrium Josephson effect through helical edge states.
TLDR
It is shown that the scattering matrix formalism shows that the fractional Josephson effect is absent in the average current, however, clear signatures can be seen in the finite-frequency current noise.
Fractional ac Josephson effect in unconventional superconductors
For certain orientations of Josephson junctions between two px-wave or two d-wave superconductors, the subgap Andreev bound states produce a 4π-periodic relation between the Josephson current I and
Current-phase relation for Josephson effect through helical metal
Josephson junctions fabricated on the surface of three-dimensional topological insulators (TI) show a few unusual properties distinct from conventional Josephson junctions. In these devices, the
Nonsinusoidal current-phase relationship in Josephson junctions from the 3D topological insulator HgTe.
TLDR
The experimental results suggest that the topological properties of the normal state can be inherited by the induced superconducting state, and that 3D HgTe is a promising material for realizing the many exciting proposals that require a topological superconductor.
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