Reducing charge noise in quantum dots by using thin silicon quantum wells

Reducing charge noise in quantum dots by using thin silicon quantum wells

Paquelet Wuetz, B.
Degli Esposti, D.
Zwerver, A.M.J.
Amitonov, S.V.
Botifoll, M.
Arbiol, J.
Vandersypen, L.M.K.
Russ, M.
Scappucci, G.

2023

Charge noise in the host semiconductor degrades the performance of spinqubits and poses an obstacle to control large quantumprocessors. However, it is challenging to engineer the heterogeneous material stack of gate-defined quantum dots to improve charge noise systematically. Here, we address the semiconductor-dielectric interface and the buried quantum well of a 28Si/SiGe heterostructure and show the connection between charge noise, measured locally in quantum dots, and global disorder in the host semiconductor, measured with macroscopicHall bars. In 5 nmthick 28Si quantumwells, we find that improvements in the scattering properties and uniformity of the twodimensional electron gas over a 100 mm wafer correspond to a significant reduction in charge noise, with a minimum value of 0.29±0.02 μeV/Hz½ at 1Hz averaged over several quantum dots.Weextrapolate the measured charge noise to simulated dephasing times to CZ-gate fidelities that improve nearly one order of magnitude. These results point to a clean and quiet crystalline environment for integrating long-lived and high-fidelity spin qubits into a larger system.

High Tech Systems & Materials
Industrial Innovation

http://resolver.tudelft.nl/uuid:eaa5ce69-b22d-4aca-b64f-8f54148030de

https://doi.org/10.1038/s41467-023-36951-w

984479

Springer Nature

Nature Communications, 14 (14)

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