Nanowire platforms for hybrid quantum dot systems
Jesper Nygård1,2
1 Niels Bohr Institute, Center for Quantum Devices, University of Copenhagen, Denmark
2 LANEF, Institut Néel, CNRS, and PHELIQS - CEA Grenoble, France
Superconductor-semiconductor nanowires have been established as an essential platform for research in quantum devices, notably used in the search for novel bound states in hybrid systems [1]. In this talk we firstly discuss the excitations and correlations arising in short chains of coupled quantum dots and superconducting islands in Al/InAs nanowires [2].
We then take a look beneath the surface of these devices, addressing advances in materials science where epitaxial growth, in situ fabrication and implementation of various superconductors have expanded the available parameter space for hybrid devices [3,4]. We will finally focus on new opportunities arising from in situ fabrication of multiple coupled nanowires [5,6,7].
[1] E. Prada et al., From Andreev to Majorana bound states in hybrid superconductor-semiconductor nanowires, Nature Reviews Physics 2, 575 (2020)
[2] J.C. Estrada Saldana et al., Excitations in a superconducting Coulombic energy gap, Nature Comm. 13, 2243 (2022); Two Bogoliubov quasiparticles entangled by a spin, arxiv:2203.00104
[3] T. Kanne et al., Epitaxial Pb on InAs nanowires for quantum devices, Nature Nanotechnology 16, 767 (2021)
[4] D. Carrad et al., Shadow Epitaxy for In Situ Growth of Generic Semiconductor-Superconductor Hybrids, Adv. Mat. 32, 1908411 (2020); M. Bjergfelt et al., Superconductivity and parity preservation in as-grown In islands on InAs nanowires, Nano Lett. 21, 9684 (2021)
[5] T. Kanne et al., Double nanowires for hybrid quantum devices, Adv. Func. Mat. 32, 2107926 (2021)
[6] O. Kürtössy et al., Parallel InAs nanowires for Cooper pair splitters with Coulomb repulsion, npj Quantum Materials 7, 88 (2022); O. Kürtössy et al., Andreev molecule in parallel InAs nanowires, Nano Lett. 22, 7929 (2021)
[7] A. Vekris et al., Josephson junctions in double nanowires bridged by in-situ deposited superconductors, Phys. Rev. Research 3, 033240 (2021), A. Vekris et al., Electronic transport in double-nanowire superconducting islands with multiple terminals, Nano Lett. 22, 5765-5772 (2022)