# Extra quantum dot improves tuning of fast spin qubits

_Published Monday, October 26, 2026 at 12:13 PM EDT · Science · Latest · Tier 2 — Notable_

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University of Osaka researchers and collaborators demonstrated a semiconductor spin qubit design that lets operating speed and resistance to voltage noise be tuned more independently after fabrication. Adding a third quantum dot reshaped electron energies while preserving the coupling needed for fast electrical control, according to research published in npj Quantum Information.

Machine learning feedback extended estimated dephasing time from about 52 nanoseconds to 580 nanoseconds. Randomized benchmarking measured 99.56% fidelity for a 4-nanosecond gate with feedback, rising to 99.72% with pulse optimization. The demonstration used GaAs quantum dots; application to silicon and germanium remains an expectation.

## Sources

- [Phys.org](https://phys.org/news/2026-10-extra-quantum-dot-stability-qubits.html)

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Canonical: https://techandbusiness.org/newswire/8NtMASkPQzGu1BqentVc0n
Published: 2026-10-26T16:13:00.658Z
Story chronology: 2026-10-26T13:40:06.000Z
Retrieved: 2026-10-26T18:55:03.052Z
Publisher: Tech & Business (techandbusiness.org)