超导绝热量子计算机基础组件的研制

Quantum computing makes use of quantum coherent superposition to provide significant quantum speedup over classical computing on some important scientific and application problem. The realization of large-scale quantum computer is of huge scientific and social value，but will also meet great challenges in science and engineering. Therefore, developing large-scale practical quantum computer needs carefully to coordinate the trade-off between three aspects: quantum coherence, scalability and scientific application from its early stage. And building a low-noise dedicated quantum computer is the optimized way to achieve practical quantum computing in the near term. Adiabatic quantum computation has the universal quantum computing power and is protected by limited energy gap to tolerate system noise. It also has wide applications in combinatorial optimization and molecular ground-state problems. This project is aimed to develop a superconducting adiabatic quantum computing prototype based on circuit-quantum electrodynamics with high quantum coherence and high architecture scalability. The basic components will include distributed quantum bits, tunable quantum coupler and high-fidelity quantum measurement. We will comprehensively analyze and test the balance between quantum coherence and scalability, and achieve high-quality and scalable adiabatic quantum computing prototype, to establish the scientific foundation of the next generation practical-scale adiabatic quantum computers.

量子计算利用量子相干叠加特性，可以在特定重要计算难题上提供超越经典计算的加速能力。实现可扩展的中大规模应用级量子计算机具有重大的科学社会价值，同时也面临巨大的科学技术挑战。因此应用级量子计算机从研制初期就需要协调考虑量子相干性、可扩展性、科学应用三者的相互配合；其中，构筑低噪声的专用量子计算机是中短期内实现应用级量子计算的最佳途径。绝热量子计算具有和门线路量子计算等价的计算能力，受有限能隙保护具有内禀的抗噪声能力，并且在组合优化、分子基态等关键科学问题上具有广泛的直接应用。本项目基于超导量子电路电动力学系统研制绝热量子计算机，致力于发展高相干度、可兼容直接大规模扩展的绝热量子计算基本组件，包括分布式量子比特、可调量子耦合和高保真量子读取等。通过实验与理论的结合，我们将全面分析量子相干性和可扩展性的平衡设计，实现高品质可扩展的绝热量子计算原型，建立下一代应用级绝热量子计算机的科学基础。

量子计算机研制是当前各国科技竞争的焦点之一，其可在特定关键问题上提供超越经典计算机的算力。本项目聚焦于研制新型绝热量子计算机组件并实现小规模集成，项目在执行期内取得了进展：.1、研制具有自主知识产权的新型超导量子比特Plasmonium，打破了transmon比特设计中电荷噪声敏感度与非简谐性之间相互制约的局限性，具有发展潜力。.2、提出超导量子比特的新型量子态读取方法，实现了压制超过90%的弛豫错误，为我国及时实现超导量子计算优越性做出了关键性的贡献。.3、提出绝热变分量子算法，实现了绝热原理和变分原理的优势结合。.4、提出高性能的量子线路的经典模拟算法，打破了之前超级计算机只能模拟50个量子比特线路的局限。.5、将小规模量子处理器应用于量子力学基础问题，实现首次通过实验证明标准量子力学需要使用复数。..这些进展实现了新型量子比特和量子读取，实现了新型绝热量子算法和经典模拟算法，实现了量子计算的重要科学应用；发表研究论文包括 Physical Review Letters 3篇和 Fundamental Research 1篇等。