Nature Communications (Feb 2024)

Spin-EPR-pair separation by conveyor-mode single electron shuttling in Si/SiGe

  • Tom Struck,
  • Mats Volmer,
  • Lino Visser,
  • Tobias Offermann,
  • Ran Xue,
  • Jhih-Sian Tu,
  • Stefan Trellenkamp,
  • Łukasz Cywiński,
  • Hendrik Bluhm,
  • Lars R. Schreiber

DOI
https://doi.org/10.1038/s41467-024-45583-7
Journal volume & issue
Vol. 15, no. 1
pp. 1 – 8

Abstract

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Abstract Long-ranged coherent qubit coupling is a missing function block for scaling up spin qubit based quantum computing solutions. Spin-coherent conveyor-mode electron-shuttling could enable spin quantum-chips with scalable and sparse qubit-architecture. Its key feature is the operation by only few easily tuneable input terminals and compatibility with industrial gate-fabrication. Single electron shuttling in conveyor-mode in a 420 nm long quantum bus has been demonstrated previously. Here we investigate the spin coherence during conveyor-mode shuttling by separation and rejoining an Einstein-Podolsky-Rosen (EPR) spin-pair. Compared to previous work we boost the shuttle velocity by a factor of 10000. We observe a rising spin-qubit dephasing time with the longer shuttle distances due to motional narrowing and estimate the spin-shuttle infidelity due to dephasing to be 0.7% for a total shuttle distance of nominal 560 nm. Shuttling several loops up to an accumulated distance of 3.36 μm, spin-entanglement of the EPR pair is still detectable, giving good perspective for our approach of a shuttle-based scalable quantum computing architecture in silicon.