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. (TU Delft BUS/Quantum Delft; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft)
Degli Esposti, D. (TU Delft QCD/Scappucci Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft)
Zwerver, A.M.J. (TU Delft QCD/Vandersypen Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft)
Amitonov, S. (TU Delft BUS/TNO STAFF; TU Delft QuTech Advanced Research Centre)
Botifoll, Marc (Catalan Institute of Nanoscience and Nanotechnology, Barcelona)
Arbiol, Jordi (Catalan Institution for Research and Advanced Studies (ICREA); Catalan Institute of Nanoscience and Nanotechnology, Barcelona)
Sammak, A. (TU Delft BUS/TNO STAFF; TU Delft QuTech Advanced Research Centre)
Vandersypen, L.M.K. (TU Delft QuTech Advanced Research Centre; TU Delft QN/Vandersypen Lab; Kavli institute of nanoscience Delft)
Russ, M.F. (TU Delft QCD/Vandersypen 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)

2023

Charge noise in the host semiconductor degrades the performance of spin-qubits and poses an obstacle to control large quantum processors. 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 macroscopic Hall bars. In 5 nm thick ²⁸Si quantum wells, we find that improvements in the scattering properties and uniformity of the two-dimensional 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/Hz^½ at 1 Hz averaged over several quantum dots. We extrapolate 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.

http://resolver.tudelft.nl/uuid:4edc49b8-63a3-46cc-9e26-1112296ce0b1

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

2041-1723

Nature Communications, 14 (1)

Erratum DOI 10.38/s41467-023-37548-z

Institutional Repository

journal article

© 2023 B. Paquelet Wuetz, D. Degli Esposti, A.M.J. Zwerver, S. Amitonov, Marc Botifoll, Jordi Arbiol, A. Sammak, L.M.K. Vandersypen, M.F. Russ, G. Scappucci