1. Epitaxial Pb on InAs nanowires for quantum devices
- Author
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Damon J. Carrad, Lunjie Zeng, Mikelis Marnauza, Erik Johnson, Dags Olsteins, Kasper Grove-Rasmussen, Joeri de Bruijckere, Joachim E. Sestoft, Thomas Kanne, Eva Olsson, and Jesper Nygård
- Subjects
Superconductivity ,Materials science ,Spins ,Condensed matter physics ,Biomedical Engineering ,Nanowire ,Macroscopic quantum phenomena ,Bioengineering ,Heterojunction ,02 engineering and technology ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Magnetic field ,Condensed Matter::Materials Science ,Condensed Matter::Superconductivity ,General Materials Science ,Grain boundary ,Electrical and Electronic Engineering ,Cooper pair ,0210 nano-technology - Abstract
Semiconductor–superconductor hybrids are widely used to realize complex quantum phenomena, such as topological superconductivity and spins coupled to Cooper pairs. Accessing new, exotic regimes at high magnetic fields and increasing operating temperatures beyond the state-of-the-art requires new, epitaxially matched semiconductor–superconductor materials. One challenge is the generation of favourable conditions for heterostructural formation between materials with the desired properties. Here we harness an increased knowledge of metal-on-semiconductor growth to develop InAs nanowires with epitaxially matched, single-crystal, atomically flat Pb films with no axial grain boundaries. These highly ordered heterostructures have a critical temperature of 7 K and a superconducting gap of 1.25 meV, which remains hard at 8.5 T, and therefore they offer a parameter space more than twice as large as those of alternative semiconductor–superconductor hybrids. Additionally, InAs/Pb island devices exhibit magnetic field-driven transitions from a Cooper pair to single-electron charging, a prerequisite for use in topological quantum computation. Semiconductor–Pb hybrids potentially enable access to entirely new regimes for a number of different quantum systems. Semiconductor–superconductor hybrids are used for realizing complex quantum phenomena but are limited in the accessible magnetic field and temperature range. Now, hybrid devices made from InAs nanowires and epitaxially matched, single-crystal, atomically flat Pb films present superior characteristics, doubling the available parameter space.
- Published
- 2021