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Fine-tuning the quantum well thickness in <sup>28</sup>Si/SiGe heterostructures

ORAL

Abstract

Advancing the materials science of quantum devices plays an essential role in pursuing larger spin-based quantum processors with more functionality. Recently, we systematically engineered the material stack focusing on the semiconductor-dielectric interface [1] and the thickness of the buried 28Si quantum well [2].

Here, we fine-tune the thickness of the quantum well between the onset of strain relaxation and the increase of scattering from the bottom interface. Statistical characterization of hallbar-shaped heterostructure field effect transistors shows a substantial increase in average mobility, low percolation density, and a small spread of these parameters. In gate-defined quantum dots, we study the effects of the new features of the material stack on crucial parameters for spin qubit operation, such as charge noise, valley splitting, and device stability.

[1] Degli Esposti, D, et al., Appl. Phys. Lett. 120, 184003 (2022)

[2] Paquelet Wuetz, B, et al., arXiv:2209.07242 (2022)

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Presenters

  • Davide Degli Esposti

    QuTech/TU Delft

Authors

  • Davide Degli Esposti

    QuTech/TU Delft

  • Lucas Stehouwer

    QuTech and Kavli Institute of Nanoscience, TU Delft, P.O. Box 5046, 2600 GA Delft, The Netherlands

  • Davide Costa

    QuTech and Kavli Institute of Nanoscience, TU Delft, P.O. Box 5046, 2600 GA Delft, The Netherlands

  • Cornelius Carlsson

    QuTech and Kavli Institute of Nanoscience, TU Delft, P.O. Box 5046, 2600 GA Delft, The Netherlands

  • Larysa Tryputen

    QuTech and TNO, Stieltjesweg 1, 2628 CK Delft, The Netherlands

  • Sergey V Amitonov

    TNO, Qutech, QuTech and TNO, Stieltjesweg 1, 2628 CK Delft, The Netherlands, QuTech and Netherlands Organization for Applied Scientific Research (TNO), Delft, The Netherlands, TNO, QuTech, TNO, TNO/QuTech

  • Amir Sammak

    TNO, Qutech, QuTech and TNO, Stieltjesweg 1, 2628 CK Delft, The Netherlands, Netherlands Organisation for Applied Scientific Research (TNO), QuTech and Netherlands Organization for Applied Scientific Research (TNO), Delft, The Netherlands, TNO, QuTech, TNO, Netherlands Organization for Applied Scientific Research (TNO), QuTech and Netherlands Organisation for Applied Scientific Research (TNO), Stieltjesweg 1, 2628 CK Delft, The Netherlands, TNO/QuTech

  • Giordano Scappucci

    QuTech and Kavli Institute of Nanoscience, TU Delft, P.O. Box 5046, 2600 GA Delft, The Netherlands, Delft University of Technology, QuTech and the Kavli Institute of Nanoscience, Delft University of Technology, TU Delft QuTech, QuTech and Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, The Netherlands