Broadband parametric amplification for multiplexed SiMOS spin qubit readout

Electron spins in semiconductor quantum dots hold great promise as building blocks of quantum processors [1]. Trapping them in SiMOS transistor-like devices eases future industrial scale fabrication [2]. In this prospect, readout schemes must enable to distinguish between the two qubit states with a fidelity above error correction thresholds, while minimizing the sensor footprint.

Gate-based radio-frequency reflectometry embodies a readout method that doesn't need additional elements to be built, outside of the transistor gates themselves. In addition, superconducting parametric amplification gives a way to significantly enhance the readout signal-to-noise ratio by reducing the noise below typical HEMT amplifiers, of around 4K noise temperature [3].

In this work, we demonstrate a 3GHz gate-based reflectometry readout of electron charge states in SiMOS multi-gate devices, enhanced with a travelling-wave superconducting parametric amplifier (TWPA) [4]. The broad 2GHz bandwidth combined with close to 12dB gain of the amplifier offers time-multiplexing interdot signal readout near the standard quantum limit of noise. In addition, the single-junction nature of the aluminum superconducting amplifier chain renders it insensitive to external magnetic field at typical spin qubit working values, up until we reach Al critical field at the position of the amplifier.

[1] Loss, D., & DiVincenzo, D. P. (1998). Quantum computation with quantum dots. Physical Review A, 57(1), 120.

[2] Maurand, R., Jehl, X., Kotekar-Patil, D., Corna, A., Bohuslavskyi, H., Laviéville, R., ... & De Franceschi, S. (2016). A CMOS silicon spin qubit. Nature communications, 7(1), 1-6.

[3] Vigneau, F., Fedele, F., Chatterjee, A., Reilly, D., Kuemmeth, F., Gonzalez-Zalba, F., ... & Ares, N. (2022). Probing quantum devices with radio-frequency reflectometry. arXiv preprint arXiv:2202.10516.

[4] Planat, L., Ranadive, A., Dassonneville, R., Martínez, J. P., Léger, S., Naud, C., ... & Roch, N. (2020). Photonic-crystal Josephson traveling-wave parametric amplifier. Physical Review X, 10(2), 021021.