Spin qubit shuttling via moving conveyor-mode quantum dots in Si/SiGe offers a promising route to scalable miniaturized quantum computing. Recent modeling of dephasing via valley degrees of freedom and well disorder dictate a slow shutting speed which seems to limit errors to above correction thresholds if not mitigated. We increase the precision of this prediction, showing that typical errors for 10 μm shuttling at constant speed results in O(1) error, using fast, automatically differentiable numerics and including improved disorder modeling and potential noise ranges. However, remarkably, we show that these errors can be brought to well below fault-tolerant thresholds using trajectory shaping with very simple parametrization with as few as 4 Fourier components, well within the means for experimental in-situ realization, and without the need for targeting or knowing the location of valley near degeneracies.
@article{arxiv.2409.07600,
title = {Long distance spin shuttling enabled by few-parameter velocity optimization},
author = {Alessandro David and Akshay Menon Pazhedath and Lars R. Schreiber and Tommaso Calarco and Hendrik Bluhm and Felix Motzoi},
journal= {arXiv preprint arXiv:2409.07600},
year = {2024}
}