Details

Autor(en) / Beteiligte

• Fornieri, Antonio
• Whiticar, Alexander M
• Setiawan, F
• Portolés, Elías
• Drachmann, Asbjørn C C
• Keselman, Anna
• Gronin, Sergei
• Thomas, Candice
• Wang, Tian
• Kallaher, Ray
• Gardner, Geoffrey C
• Berg, Erez
• Manfra, Michael J
• Stern, Ady
• Marcus, Charles M
• Nichele, Fabrizio

Titel

Evidence of topological superconductivity in planar Josephson junctions

Ist Teil von

• Nature (London), 2019-05, Vol.569 (7754), p.89-92

Ort / Verlag

England: Nature Publishing Group

Erscheinungsjahr

2019

Beschreibungen/Notizen

• Majorana zero modes-quasiparticle states localized at the boundaries of topological superconductors-are expected to be ideal building blocks for fault-tolerant quantum computing . Several observations of zero-bias conductance peaks measured by tunnelling spectroscopy above a critical magnetic field have been reported as experimental indications of Majorana zero modes in superconductor-semiconductor nanowires . On the other hand, two-dimensional systems offer the alternative approach of confining Majorana channels within planar Josephson junctions, in which the phase difference φ between the superconducting leads represents an additional tuning knob that is predicted to drive the system into the topological phase at lower magnetic fields than for a system without phase bias . Here we report the observation of phase-dependent zero-bias conductance peaks measured by tunnelling spectroscopy at the end of Josephson junctions realized on a heterostructure consisting of aluminium on indium arsenide. Biasing the junction to φ ≈ π reduces the critical field at which the zero-bias peak appears, with respect to φ = 0. The phase and magnetic-field dependence of the zero-energy states is consistent with a model of Majorana zero modes in finite-size Josephson junctions. As well as providing experimental evidence of phase-tuned topological superconductivity, our devices are compatible with superconducting quantum electrodynamics architectures and are scalable to the complex geometries needed for topological quantum computing .