Filters

2018 - 20192

More filters

2022 - 20232
Reset filters

Settings

Start date: 2010 × Has files: Yes × Type: Text × Version: publishedVersion × Publisher: [London] : Nature Publishing Group UK × Subject: electrical conductivity × Subject: quantum mechanics ×

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Sound-driven single-electron transfer in a circuit of coupled quantum rails
    ([London] : Nature Publishing Group UK, 2019) Takada, Shintaro; Edlbauer, Hermann; Lepage, Hugo V.; Wang, Junliang; Mortemousque, Pierre-André; Georgiou, Giorgos; Barnes, Crispin H. W.; Ford, Christopher J. B.; Yuan, Mingyun; Santos, Paulo V.; Waintal, Xavier; Ludwig, Arne; Wieck, Andreas D.; Urdampilleta, Matias; Meunier, Tristan; Bäuerle, Christopher
    Surface acoustic waves (SAWs) strongly modulate the shallow electric potential in piezoelectric materials. In semiconductor heterostructures such as GaAs/AlGaAs, SAWs can thus be employed to transfer individual electrons between distant quantum dots. This transfer mechanism makes SAW technologies a promising candidate to convey quantum information through a circuit of quantum logic gates. Here we present two essential building blocks of such a SAW-driven quantum circuit. First, we implement a directional coupler allowing to partition a flying electron arbitrarily into two paths of transportation. Second, we demonstrate a triggered single-electron source enabling synchronisation of the SAW-driven sending process. Exceeding a single-shot transfer efficiency of 99%, we show that a SAW-driven integrated circuit is feasible with single electrons on a large scale. Our results pave the way to perform quantum logic operations with flying electron qubits. © 2019, The Author(s).
  • Thumbnail Image
    Item
    Gate-controlled quantum dots and superconductivity in planar germanium
    ([London] : Nature Publishing Group UK, 2018) Hendrickx, N.W.; Franke, D.P.; Sammak, A.; Kouwenhoven, M.; Sabbagh, D.; Yeoh, L.; Li, R.; Tagliaferri, M.L.V.; Virgilio, M.; Capellini, G.; Scappucci, G.; Veldhorst, M.
    Superconductors and semiconductors are crucial platforms in the field of quantum computing. They can be combined to hybrids, bringing together physical properties that enable the discovery of new emergent phenomena and provide novel strategies for quantum control. The involved semiconductor materials, however, suffer from disorder, hyperfine interactions or lack of planar technology. Here we realise an approach that overcomes these issues altogether and integrate gate-defined quantum dots and superconductivity into germanium heterostructures. In our system, heavy holes with mobilities exceeding 500,000 cm2 (Vs)−1 are confined in shallow quantum wells that are directly contacted by annealed aluminium leads. We observe proximity-induced superconductivity in the quantum well and demonstrate electric gate-control of the supercurrent. Germanium therefore has great promise for fast and coherent quantum hardware and, being compatible with standard manufacturing, could become a leading material for quantum information processing.