Semiconductor quantum dot arrays are a promising platform to perform spin-based error-corrected quantum computation with large numbers of qubits. However, due to the diverging number of possible charge configurations combined with the limited sensitivity of large-footprint charge sensors, achieving single-spin occupancy in each dot in a growing quantum dot array is exceedingly complex. Therefore, to scale-up a spin-based architecture we must change how individual charges are readout and controlled. Here, we demonstrate single-spin occupancy of each dot in a foundry-fabricated array by combining two methods. 1/ Loading a finite number of electrons into the quantum dot array; simplifying electrostatic tuning by isolating the array from the reservoirs. 2/ Deploying multiplex gate-based reflectometry to dispersively probe charge tunneling and spin states without charge sensors or reservoirs. Our isolated arrays probed by embedded multiplex readout can be readily electrostatically tuned. They are thus a viable, scalable approach for spin-based quantum architectures.
@article{arxiv.2410.02325,
title = {Combining multiplexed gate-based readout and isolated CMOS quantum dot arrays},
author = {Pierre Hamonic and Martin Nurizzo and Jayshankar Nath and Matthieu C. Dartiailh and Victor El-Homsy and Mathis Fragnol and Biel Martinez and Pierre-Louis Julliard and Bruna Cardoso Paz and Mathilde Ouvrier-Buffet and Jean-Baptiste Filippini and Benoit Bertrand and Heimanu Niebojewski and Christopher Bäuerle and Maud Vinet and Franck Balestro and Tristan Meunier and Matias Urdampilleta},
journal= {arXiv preprint arXiv:2410.02325},
year = {2024}
}