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)
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)
*This research was supported by the European Union's Horizon 2020 research and innovation programme under the Grant Agreement No. 951852 (QLSI project)
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Presenters
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Davide Degli Esposti
- QuTech/TU Delft