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arXiv · 2605.12687

Using a spin-triplet encoding to enhance shuttling fidelities in Si/SiGe quantum wells

Merritt P. R. Losert·S. N. Coppersmith·Mark Friesen
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Abstract

Spatial variations of the valley splitting in a quantum well present a key challenge for conveyor-mode shuttling of electron spins in Si/SiGe, giving rise to Landau-Zener-like excitations that cause leakage outside the qubit subspace. Here, we propose an unconventional two-electron qubit encoding, based on valley-singlet states, that is largely immune to Landau-Zener leakage processes. In contrast to single-electron spins, the shuttling fidelity actually improves for small valley splittings, in this case. We show that high fidelities can be achieved without applying any special procedures, such as fine-tuning of the shuttling path.

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Merritt P. R. Losert, S. N. Coppersmith, Mark Friesen. 2026-05-12. Using a spin-triplet encoding to enhance shuttling fidelities in Si/SiGe quantum wells. https://arxiv.org/abs/2605.12687

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