Cryogenic Control of Spin Qubits

Silicon-based qubit systems hold significant promise as a platform for quantum computers. Over the past few decades, the field has seen remarkable progress, culminating in high-fidelity, multi-qubit devices today, based on silicon quantum dots (Xue, et al., 2022) (Steinacker, et al., 2024). However, to realize practical quantum computers, the number of qubits must increase substantially. The addressability and control of each quantum dot are crucial for operating the quantum processor. In this talk, we will focus on two essential modules: a DC multiplexer (DC MUX) and a radio-frequency single-electron transistor (RF-SET), to interface with the quantum dots and ensure full addressability in a scalable way. We will show experimental data of RF reflectometry on home-built quantum dot devices (Koch, et al., 2024), resulting in fast single shot readout on timescales well below 1us. We will also present experimental results of DC MUX interfacing of small quantum dot arrays, and demonstrate how it can help solve upscaling and addressing issues of large quantum dot arrays. Together, these results offer an indication of the value of fully integrated cryogenic control and readout for silicon quantum dot systems.

 

Bibliography

Koch, T., Godfrin, C., Adam, V., Ferrero, J., Schroller, D., Glaeser, N., . . . Wernsdorfer, W. (2024). Industrial 300mm wafer processed spin qubits in natural silicon/silicon-germanium. doi: 10.48550/arXiv.2409.12731

Steinacker, P., Stuyck, N. D., Lim, W. H., Tanttu, T., Feng, M., Nickl, A., . . . Dzurak, A. S. (2024, October). A 300 mm foundry silicon spin qubit unit cell exceeding 99% fidelity in all operations. doi:10.48550/ARXIV.2410.15590

Xue, X., Russ, M., Samkharadze, N., Undseth, B., Sammak, A., Scappucci, G., & Vandersypen, L. M. (2022, January). Quantum logic with spin qubits crossing the surface code threshold. Nature, 601, 343–347. doi:10.1038/s41586-021-04273-w