Reducing charge noise in quantum dots by using thin silicon quantum wells
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...
| Autores: | , , , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2023 |
| País: | España |
| Institución: | Universitat Autònoma de Barcelona |
| Repositorio: | Dipòsit Digital de Documents de la UAB |
| Idioma: | inglés |
| OAI Identifier: | oai:ddd.uab.cat:282640 |
| Acceso en línea: | https://ddd.uab.cat/record/282640 https://dx.doi.org/urn:doi:10.1038/s41467-023-36951-w |
| Access Level: | acceso abierto |
| Palabra clave: | Quantum dots Spintronics |
| Sumario: | 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 28 Si/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 28 Si 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 -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. Charge noise degrades the performance of spin qubits hindering scalability. Here the authors engineer the heterogeneous material stack in 28 Si/SiGe gate-defined quantum dots, to improve the scattering properties and to reduce charge noise. |
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