Suppressing spin qubit decoherence during shuttling via confinement modulation

TL;DR

This paper proposes confinement modulation techniques for spin qubits to suppress decoherence during long-range shuttling, enhancing coherence by continuous dynamical decoupling and spin-orbit interactions.

Contribution

It introduces temporal and spatial breathing shuttling protocols leveraging spin-orbit coupling for noise-resilient qubit transport.

Findings

Confinement-modulated shuttling significantly improves coherence during transport.

The protocols effectively mitigate low-frequency magnetic and electric noise.

Limitations depend on the noise correlation length, affecting protocol performance.

Abstract

Reliable long-range qubit shuttling is a powerful tool for scalable quantum computing architectures. We investigate strategies to improve the coherence of moving spin qubits by performing continuous dynamical decoupling by modulating their confinement potential. Specifically, we introduce temporal and spatial breathing shuttling protocols that leverage spin-orbit interactions in hole-spin systems to electrically drive the qubit while moving. This enables efficient dressed-state shuttling, where the spin is continuously rotated during transport, suppressing the effect of low-frequency noise. Using the filter function formalism, we identify driving regimes that efficiently mitigate both global and local magnetic and electric noise sources. We find that confinement-modulated shuttling can significantly enhance coherence during transport, while revealing distinct limitations depending on the correlation length of the noise. Applying our framework to germanium hole-spin qubits, we show that these protocols provide a practical route toward noise-resilient long-range coherent quantum links.