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Quantized Majorana conductance (Publication with Expression of Concern. See vol. 581, 2020)

Abstract

Majorana zero-modes-a type of localized quasiparticle-hold great promise for topological quantum computing(1). 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 conductance(2). The height of the Majorana zero-bias peak is predicted to be quantized at the universal conductance value of 2e(2)/h at zero temperature(3) (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 coupling(3-5). Previous experiments(6), however, have mostly shown zero-bias peaks much smaller than 2e(2)/h, with a recent observation(7) of a peak height close to 2e(2)/h. Here we report a quantized conductance plateau at 2e(2)/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.

Publication Details

Authors
Publication Type
Journal Article
Year of Publication
2018
Journal
Nature
Volume
556
Pagination
74-+

Contributors

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