High density packaging for large spin qubit array

In the past year the community has demonstrated the implementation of large spin qubits arrays [1,2] as well as the successful fabrication and operation of devices in CMOS foundries [3]. To allow for further development of this platform, packaging supporting larger arrays with high fidelity operations, extended bandwidth and compact formfactor is vital.



In this talk we show initial results obtained on the new packaging solution which enables up to 32 spin qubits while being compatible with vector magnets with a standard 80 mm bore. This packaging is based on a motherboard-daughterboard solution, as implemented in our Qboard-II packaging [4]. To allow for a high number of control lines, an interface to high-density flex cabling has been developed in collaboration with Delft Circuits [5]. We will show initial characterization results performed at cryogenic temperatures, focusing on S parameters statistics. Furthermore, we will present data on time domain analysis to evaluate the quality of the 50-ohm matching including flex cabling and flex-to-board interface.



[1] Philips et al., Nature 609, 919 (2022)

[2] F. Borsoi et al., Nature Nanotechnology 19,21 (2024)

[3] P. Steinacker et al., arXiv:2410.15590 (2024)

[4] https://www.quantum-machines.co/products/qboard/

[5] V. Monarkha et al., Appl. Phys. Lett., 124 224001 (2024)