Struck Tom, Volmer Mats, Visser Lino, Offermann Tobias, Xue Ran, Tu Jhih-Sian, Trellenkamp Stefan, Cywiński Łukasz, Bluhm Hendrik, Schreiber Lars R
JARA-FIT Institute for Quantum Information, Forschungszentrum Jülich GmbH and RWTH Aachen University, Aachen, Germany.
ARQUE Systems GmbH, Aachen, Germany.
Nat Commun. 2024 Feb 13;15(1):1325. doi: 10.1038/s41467-024-45583-7.
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.
长程相干量子比特耦合是扩大基于自旋量子比特的量子计算解决方案规模所缺失的功能模块。自旋相干传输模式电子穿梭可实现具有可扩展和稀疏量子比特架构的自旋量子芯片。其关键特性是仅通过少数易于调谐的输入端子进行操作，并与工业栅极制造兼容。此前已证明在420纳米长的量子总线中以传输模式进行单电子穿梭。在此，我们通过分离和重新结合爱因斯坦 - 波多尔斯基 - 罗森（EPR）自旋对来研究传输模式穿梭过程中的自旋相干性。与之前的工作相比，我们将穿梭速度提高了10000倍。由于运动窄化，我们观察到随着穿梭距离增加，自旋量子比特的退相干时间延长，并且对于标称总穿梭距离为560纳米的情况，估计由于退相干导致的自旋穿梭失准度为0.7%。穿梭几个循环直至累积距离达到3.36微米时，EPR对的自旋纠缠仍然可检测到，这为我们基于穿梭的硅基可扩展量子计算架构方法提供了良好的前景。
