Abstract

Majorana zero-modes—a type of localized quasiparticle—hold great promise for topological quantum computing1. Tunnelling spectroscopy in electrical transport is the primary tool for identifying the presence of Majorana zero-modes, for instance as a zero-bias peak in differential conductance2. The height of the Majorana zero-bias peak is predicted to be quantized at the universal conductance value of 2e2/h at zero temperature3 (where e is the charge of an electron and h is the Planck constant), as a direct consequence of the famous Majorana symmetry in which a particle is its own antiparticle. The Majorana symmetry protects the quantization against disorder, interactions and variations in the tunnel coupling3,4,5. Previous experiments6, however, have mostly shown zero-bias peaks much smaller than 2e2/h, with a recent observation7 of a peak height close to 2e2/h. Here we report a quantized conductance plateau at 2e2/h in the zero-bias conductance measured in indium antimonide semiconductor nanowires covered with an aluminium superconducting shell. The height of our zero-bias peak remains constant despite changing parameters such as the magnetic field and tunnel coupling, indicating that it is a quantized conductance plateau. We distinguish this quantized Majorana peak from possible non-Majorana origins by investigating its robustness to electric and magnetic fields as well as its temperature dependence. The observation of a quantized conductance plateau strongly supports the existence of Majorana zero-modes in the system, consequently paving the way for future braiding experiments that could lead to topological quantum computing.

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Acknowledgements

We thank M. Wimmer and Ö. Gül for discussions. This work has been supported by the European Research Council, the Dutch Organization for Scientific Research, the Office of Naval Research, the Laboratory for Physical Sciences and Microsoft Corporation Station-Q.

Author information

Author notes

    • Hao Zhang
    • , Chun-Xiao Liu
    •  & Sasa Gazibegovic

    These authors contributed equally to this work.

Affiliations

  1. QuTech and Kavli Institute of NanoScience, Delft University of Technology, 2600 GA Delft, The Netherlands

    • Hao Zhang
    • , Di Xu
    • , Guanzhong Wang
    • , Nick van Loo
    • , Jouri D. S. Bommer
    • , Michiel W. A. de Moor
    •  & Leo P. Kouwenhoven
  2. Condensed Matter Theory Center and Joint Quantum Institute, Department of Physics, University of Maryland, College Park, Maryland 20742, USA

    • Chun-Xiao Liu
    •  & S. Das Sarma
  3. Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands

    • Sasa Gazibegovic
    • , Diana Car
    • , Roy L. M. Op het Veld
    • , Petrus J. van Veldhoven
    • , Sebastian Koelling
    • , Marcel A. Verheijen
    •  & Erik P. A. M. Bakkers
  4. Materials Engineering, University of California Santa Barbara, Santa Barbara, California 93106, USA

    • John A. Logan
    • , Daniel J. Pennachio
    • , Borzoyeh Shojaei
    •  & Chris J. Palmstrøm
  5. Philips Innovation Services Eindhoven, High Tech Campus 11, 5656AE Eindhoven, The Netherlands

    • Marcel A. Verheijen
  6. Electrical and Computer Engineering, University of California Santa Barbara, Santa Barbara, California 93106, USA

    • Mihir Pendharkar
    •  & Chris J. Palmstrøm
  7. California NanoSystems Institute, University of California Santa Barbara, Santa Barbara, California 93106, USA

    • Borzoyeh Shojaei
    • , Joon Sue Lee
    •  & Chris J. Palmstrøm
  8. Microsoft Station Q Delft, 2600 GA Delft, The Netherlands

    • Leo P. Kouwenhoven

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Contributions

H.Z., D.X., G.W., N.v.L., J.D.S.B. and M.W.A.d.M. fabricated the devices, performed electrical measurements and analysed the experimental data. S.G., J.A.L., D.C., R.L.M.O.h.V., P.J.v.V., S.K., M.A.V., M.P., D.J.P., B.S., J.S.L., C.J.P. and E.P.A.M.B. grew the nanowires with epitaxial Al and performed the nanowire deposition. C.-X.L. and S.D.S. performed the numerical simulations. The manuscript was written by H.Z. and L.P.K. with comments from all authors.

Competing interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to Hao Zhang or Leo P. Kouwenhoven.

Reviewer Information Nature thanks M. Franz and the other anonymous reviewer(s) for their contribution to the peer review of this work.

Publisher's note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

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https://doi.org/10.1038/nature26142

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