NQCP - Life in Quantum - Spin Pilot Line Lead - Francesco Borsoi, Niels Bohr Institute

Interfacing μm-scale spin qubit arrays

This talk explores recent advancements in interfacing micrometer-scale spin qubit arrays based on Ge/SiGe heterostructures, highlighting innovations in quantum control, material engineering, and automation. First, I will discuss the realization of high-fidelity single- and two-qubit gates, achieved through the precise hopping of single spins across quantum dot sites with varying quantization axes [1]. Second, I will showcase a comprehensive study over noise on low-disorder epitaxial Ge/SiGe heterostructures grown on germanium wafers, that provides a benchmark of charge noise for quantum confined holes and precise estimation of the magnetic noise components [2]. Finally, I will introduce automation in the control workflow, through the Modular Autonomous Virtualization System (MAViS), which utilizes machine learning and regression models to achieve targeted and precise control over the key Hamiltonian parameters that regulate the electrostatics [3].

[1] Wang, C.-A., et al., "Operating semiconductor quantum processors with hopping spins," Science, vol. 385, pp. 447–451, 2024. DOI: 10.1126/science.ado5915.

[2] Stehouwer, L. E. A., et al., "Exploiting epitaxial strained germanium for scaling low noise spin qubits at the micron scale," arXiv preprint, arXiv:2411.11526, 2024.

[3] Rao, A. S., et al., "MAViS: Modular Autonomous Virtualization System for Two-Dimensional Semiconductor Quantum Dot Arrays," arXiv preprint, arXiv:2411.12516, 2024.