RETRACTED ARTICLE: Quantized Majorana conductance

In a step towards topological quantum computation, a quantized Majorana conductance has been demonstrated for a semiconducting nanowire coupled to a superconductor. Majorana modes braced for braiding A semiconducting nanowire coupled to a superconductor can be tuned to topological superconducting states, which are thought to host localized quasiparticles called Majorana zero-modes at the ends of the wire. Such modes obey non-Abelian statistics, and braiding them could lead to a new type of computing known as topological quantum computation. Their name comes from the connection to Majorana fermions, which are their own antiparticle. This particle–antiparticle symmetry should make Majorana zero-modes detectable through differential conductance experiments, as a peak at zero-bias should emerge that is quantized at the universal conductance value of 2 e 2 / h . Previous experiments have shown interesting features in such zero-bias peaks, but quantized conductance has remained elusive. Leo Kouwenhoven and colleagues now demonstrate a quantized Majorana conductance that is robust against electric and magnetic fields. This is an important step towards braiding experiments. 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 2 e 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 , 4 , 5 . Previous experiments 6 , however, have mostly shown zero-bias peaks much smaller than 2 e 2 / h , with a recent observation 7 of a peak height close to 2 e 2 / h . Here we report a quantized conductance plateau at 2 e 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 pe