Strong spin-orbit semiconductor nanowires coupled to a superconductor are predicted to host Majorana zero modes. Exchange (braiding) operations of Majorana modes form the logical gates of a topological quantum computer and require a network of nanowires. Here, we develop an in-plane selective-area growth technique for InSb-Al semiconductor-superconductor nanowire networks with excellent quantum transport properties. Defect-free transport channels in InSb nanowire networks are realized on insulating, but heavily mismatched InP substrates by 1) full relaxation of the lattice mismatch at the nanowire/substrate interface on a (111)B substrate orientation, 2) nucleation of a complete network from a single nucleation site, which is accomplished by optimizing the surface diffusion length of the adatoms. Essential quantum transport phenomena for topological quantum computing are demonstrated in these structures including phase-coherent transport up to 10 μm and a hard superconducting gap accompanied by 2e-periodic Coulomb oscillations with an Al-based Cooper pair island integrated in the nanowire network.
@article{arxiv.2103.06793,
title = {In-plane selective area InSb-Al nanowire quantum networks},
author = {Roy L. M. Op het Veld and Di Xu and Vanessa Schaller and Marcel A. Verheijen and Stan M. E. Peters and Jason Jung and Chuyao Tong and Qingzhen Wang and Michiel W. A. de Moor and Bart Hesselmann and Kiefer Vermeulen and Jouri D. S. Bommer and Joon Sue Lee and Andrey Sarikov and Mihir Pendharkar and Anna Marzegalli and Sebastian Koelling and Leo P. Kouwenhoven and Leo Miglio and Chris J. Palmstrøm and Hao Zhang and Erik P. A. M. Bakkers},
journal= {arXiv preprint arXiv:2103.06793},
year = {2021}
}
Comments
Data repository is available at https://doi.org/10.5281/zenodo.4589484 . Author version of the text before peer review, while see DOI for the published version