Print Email Facebook Twitter Low disorder and high valley splitting in silicon Title Low disorder and high valley splitting in silicon Author Degli Esposti, D. (TU Delft QCD/Scappucci Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Stehouwer, L.E.A. (TU Delft QCD/Scappucci Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Gül, Önder (TU Delft QRD/Kouwenhoven Lab; TU Delft QuTech Advanced Research Centre; TNO) Samkharadze, Nodar (TU Delft BUS/TNO STAFF; TU Delft QuTech Advanced Research Centre; TNO) Déprez, C.C. (TU Delft QCD/Veldhorst Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Meyer, M. (TU Delft QCD/Veldhorst Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Meijer, Ilja N. (Kavli institute of nanoscience Delft; Student TU Delft) Tryputen, L. (TU Delft BUS/TNO STAFF; TU Delft QuTech Advanced Research Centre; TNO) Karwal, S. (TU Delft BUS/TNO STAFF; TU Delft QuTech Advanced Research Centre; TNO) Vandersypen, L.M.K. (TU Delft QuTech Advanced Research Centre; TU Delft QN/Vandersypen Lab; Kavli institute of nanoscience Delft) Sammak, A. (TU Delft BUS/TNO STAFF; TU Delft QuTech Advanced Research Centre; TNO) Veldhorst, M. (TU Delft QN/Veldhorst Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Scappucci, G. (TU Delft QCD/Scappucci Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Date 2024 Abstract The electrical characterisation of classical and quantum devices is a critical step in the development cycle of heterogeneous material stacks for semiconductor spin qubits. In the case of silicon, properties such as disorder and energy separation of conduction band valleys are commonly investigated individually upon modifications in selected parameters of the material stack. However, this reductionist approach fails to consider the interdependence between different structural and electronic properties at the danger of optimising one metric at the expense of the others. Here, we achieve a significant improvement in both disorder and valley splitting by taking a co-design approach to the material stack. We demonstrate isotopically purified, strained quantum wells with high mobility of 3.14(8) × 105 cm2 V−1 s−1 and low percolation density of 6.9(1) × 1010 cm−2. These low disorder quantum wells support quantum dots with low charge noise of 0.9(3) μeV Hz−1/2 and large mean valley splitting energy of 0.24(7) meV, measured in qubit devices. By striking the delicate balance between disorder, charge noise, and valley splitting, these findings provide a benchmark for silicon as a host semiconductor for quantum dot qubits. We foresee the application of these heterostructures in larger, high-performance quantum processors. To reference this document use: http://resolver.tudelft.nl/uuid:c4c1a755-e776-45a3-9660-14050242eca8 DOI https://doi.org/10.1038/s41534-024-00826-9 ISSN 2056-6387 Source NPJ Quantum Information, 10 (1) Part of collection Institutional Repository Document type journal article Rights © 2024 D. Degli Esposti, L.E.A. Stehouwer, Önder Gül, Nodar Samkharadze, C.C. Déprez, M. Meyer, Ilja N. Meijer, L. Tryputen, S. Karwal, L.M.K. Vandersypen, A. Sammak, M. Veldhorst, G. Scappucci Files PDF s41534-024-00826-9.pdf 2.66 MB Close viewer /islandora/object/uuid:c4c1a755-e776-45a3-9660-14050242eca8/datastream/OBJ/view