We detect correlations in qubit-energy fluctuations of non-neighboring qubits defined in isotopically purified Si/SiGe quantum dots. At low frequencies (where the noise is strongest), the correlation coefficient reaches 10% for a next-nearest-neighbor qubit-pair separated by 200 nm. Assigning the observed noise to be of electrical origin, a simple theoretical model quantitatively reproduces the measurements and predicts a polynomial decay of correlations with interqubit distance. Our results quantify long-range correlations of noise dephasing quantum-dot spin qubits arranged in arrays, essential for scalability and fault-tolerance of such systems.
@article{arxiv.2302.11717,
title = {Spatial noise correlations beyond nearest-neighbor in ${}^{28}$Si/SiGe spin qubits},
author = {Juan S. Rojas-Arias and Akito Noiri and Peter Stano and Takashi Nakajima and Jun Yoneda and Kenta Takeda and Takashi Kobayashi and Amir Sammak and Giordano Scappucci and Daniel Loss and Seigo Tarucha},
journal= {arXiv preprint arXiv:2302.11717},
year = {2023}
}