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The Germanium Spin Qubit Cut Drive Power by 25 Decibels

A flopping-mode design reached 99.76% single-qubit gate fidelity at a five-millitesla field.

Published Updated Story ID: mp-2026-09-18-012
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Summary

A flopping-mode design reached 99.76% single-qubit gate fidelity at a five-millitesla field.

The experiment delocalized one hole spin across a double quantum dot, combining a charge-noise sweet spot with efficient electric-dipole spin resonance. At an almost in-plane five-millitesla magnetic field, the device used -52 dBm of drive power rather than the roughly -27 dBm cited for conventional planar germanium operation. It achieved up to 99.76% single-qubit gate fidelity with an 88-nanosecond pi rotation, 1.4 microseconds of inhomogeneous coherence, and 130 microseconds under a 32-pulse CPMG sequence. The authors identify a two-photon relaxation process as a route for further optimization.

Why it matters

A flopping-mode design reached 99.76% single-qubit gate fidelity at a five-millitesla field.

Limits and context

No additional limitation was separately recorded.

Key claims

  1. A flopping-mode design reached 99.76% single-qubit gate fidelity at a five-millitesla field.

    Evidence: source-2026-09-18-012

Sources

  1. arXiv preprint 2609.20775arXiv · primary research

Corrections

No corrections have been recorded for this story.