Spin-qubits based on impurities such as phosphorus in silicon (Si) have attractive attributes for the development of quantum computing devices. Very long coherence times can be achieved for donor-based qubits in Si due to the availability of isotopically pure ²⁸Si layers where the ²⁹Si atoms, which otherwise lead to decoherence, are largely absent in the active region of the device. Well-behaved single donor qubits in Si can routinely be formed using ion implantation, and the key performance criteria needed to demonstrate the basis of a viable platform for quantum computing have been achieved. The crucial next stage of development is to demonstrate suitable pathways for scale-up that allow patterned arrays of donor qubits to be controllably coupled and that are robust against the inherent donor placement tolerances and material processing constraints that exist. Here, we review progress on the fabrication and measurement of donor-based qubits in silicon via the ion implantation pathway and discuss the key developmental milestones that have been achieved. We also provide an overview of the key scale-up strategies that are being actively pursued to take donor-based quantum computing in Si to the next stage.

中文翻译：

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用于硅量子计算的基于供体的量子位

基于硅 (Si) 中的磷等杂质的自旋量子位对于量子计算设备的开发具有吸引力。由于同位素纯²⁸ Si 层的可用性，其中²⁹否则会导致退相干的 Si 原子在器件的有源区中基本上不存在。Si 中性能良好的单供体量子位通常可以使用离子注入形成，并且已经实现了证明可行的量子计算平台基础所需的关键性能标准。关键的下一个发展阶段是展示合适的放大途径，允许供体量子位的图案阵列可控耦合，并且对固有的供体放置公差和存在的材料加工限制具有鲁棒性。在这里，我们回顾了通过离子注入途径在硅中制造和测量基于供体的量子位的进展，并讨论了已实现的关键发展里程碑。