Charge noise is one of the main sources of environmental decoherence for spin qubits in silicon, presenting a major obstacle in the path towards highly scalable and reproducible qubit fabrication. Here we demonstrate in-depth characterization of the charge noise environment experienced by a quantum dot in a CMOS-fabricated silicon nanowire. We probe the charge noise for different quantum dot configurations, finding that it is possible to tune the charge noise over two orders of magnitude, ranging from 1 ueV^2 to 100 ueV^2. In particular, we show that the top interface and the reservoirs are the main sources of charge noise and their effect can be mitigated by controlling the quantum dot extension. Additionally, we demonstrate a novel method for the measurement of the charge noise experienced by a quantum dot in the few electron regime. We measure a comparatively higher charge noise value of 40 ueV^2 at the first electron, and demonstrate that the charge noise is highly dependent on the electron occupancy of the quantum dot.
@article{arxiv.2209.01853,
title = {Probing charge noise in few electron CMOS quantum dots},
author = {Cameron Spence and Bruna Cardoso-Paz and Vincent Michal and Emmanuel Chanrion and David J. Niegemann and Baptiste Jadot and Pierre-André Mortemousque and Bernhard Klemt and Vivien Thiney and Benoit Bertrand and Louis Hutin and Christopher Bäuerle and Franck Balestro and Maud Vinet and Yann-Michel Niquet and Tristan Meunier and Matias Urdampilleta},
journal= {arXiv preprint arXiv:2209.01853},
year = {2022}
}
Comments
6 pages 5 figures, supplementary materials included