High-fidelity spin qubit operation and algorithmic initialization above 1 K

• 成果类型: Article
• 署名作者: Huang, Jonathan Y.; Su, Rocky Y.; Lim, Wee Han; Feng, Mengke; van Straaten, Barnaby; Severin, Brandon; Gilbert, Will; Stuyck, Nard Dumoulin; Tanttu, Tuomo; Serrano, Santiago; Cifuentes, Jesus D.; Hansen, Ingvild; Seedhouse, Amanda E.; Vahapoglu, Ensar; Leon, Ross C. C.; Abrosimov, Nikolay V.; Pohl, Hans-Joachim; Thewalt, Michael L. W.; Hudson, Fay E.; Escott, Christopher C.; Ares, Natalia; Bartlett, Stephen D.; Morello, Andrea; Saraiva, Andre; Laucht, Arne; Dzurak, Andrew S.; Yang, Chih Hwan
• 署名单位: University of New South Wales Sydney; University of Oxford; Leibniz Association; Leibniz Institut fur Kristallzuchtung (IKZ); Simon Fraser University; University of Sydney
• 刊物名称: Nature
• ISSN/ISSBN: 0028-5280
• DOI: 10.1038/s41586-024-07160-2
• 发表日期: 2024-03-28
• 关键词: pulmonary neuroepithelial bodies; vagal sensory neurons; neuroendocrine cells; blood-pressure; airway; deflation; receptors; inflation; stretch; reflex

摘要

The encoding of qubits in semiconductor spin carriers has been recognized as a promising approach to a commercial quantum computer that can be lithographically produced and integrated at scale 1-10 . However, the operation of the large number of qubits required for advantageous quantum applications 11-13 will produce a thermal load exceeding the available cooling power of cryostats at millikelvin temperatures. As the scale-up accelerates, it becomes imperative to establish fault-tolerant operation above 1 K, at which the cooling power is orders of magnitude higher 14-18 . Here we tune up and operate spin qubits in silicon above 1 K, with fidelities in the range required for fault-tolerant operations at these temperatures 19-21 . We design an algorithmic initialization protocol to prepare a pure two-qubit state even when the thermal energy is substantially above the qubit energies and incorporate radiofrequency readout to achieve fidelities up to 99.34% for both readout and initialization. We also demonstrate single-qubit Clifford gate fidelities up to 99.85% and a two-qubit gate fidelity of 98.92%. These advances overcome the fundamental limitation that the thermal energy must be well below the qubit energies for the high-fidelity operation to be possible, surmounting a main obstacle in the pathway to scalable and fault-tolerant quantum computation. Initialization and operation of spin qubits in silicon above 1 K reach fidelities sufficient for fault-tolerant operations at these temperatures.