Building and exploiting a high-performance monolithic trapped-ion quantum computer

该项目旨在开发世界上性能最高的量子处理器——一种新型计算机，它以一种与传统计算机截然不同且更强大的方式处理信息。足够大的量子计算机可以解决任何类型的非量子（“经典”）硬件上难以解决的问题。例如，量子计算机将能够模拟在经典超级计算机上无法模拟的复杂问题的物理或化学。这将对科学研究产生深远影响，并使人们能够接触到目前超出实验或理论范围的制度；比如量子化学，或者凝聚态物理。尽管量子计算的实验工作已经进行了20年，但具有如此计算能力的量子处理器仍然超出了实验的范围。捕获离子技术的最新进展意味着，在这个项目的时间框架内，这样的机器现在是可以实现的。近年来，各种各样的技术已经被用来证明量子计算机的构建模块可以很好地工作，以执行有用的现实世界计算。对于所有技术来说，现在的挑战是开发具有大量量子比特（量子比特，量子计算机中的基本信息单位）的系统，这些系统具有量子计算所必需的量子比特到量子比特的连通性，同时最大限度地减少操作错误。该领域的最终目标是构建包含数十万个有效完美量子比特的处理器，所有量子比特都由高精度量子逻辑门连接。这种全尺寸的量子计算机将改变21世纪，就像经典计算机改变了20世纪一样。然而，建造如此复杂的处理器仍然是一项艰巨的工程挑战，需要大量的资源，并持续数十年。相反，这个项目的重点是尝试和瞄准一个现实的近期目标。利用捕获的原子离子作为量子比特，并利用这些量子比特已经证明的高保真度和高连接门，我们的目标是制造一个至少具有50个量子比特的处理器，其门误差足够低，可以执行数千个门的电路。这种中等规模的量子处理器甚至超出了我们最强大的经典超级计算机的模仿能力。有了这个处理器，我们的目标是展示潜在的量子计算机必须用“量子优势”解决现实世界的问题。此外，我们的目标是开发和测试抗噪声方法，以从中等规模的处理器中提取最大性能，例如错误缓解协议和混合量子经典算法。然而，正如经典计算的历史告诉我们的那样，在真正的量子硬件上开发和原型化新技术的能力，最大的回报很可能来自意想不到的方向。这个项目将提供这些硬件。

This project is aimed at developing the world's highest-performance quantum processor - a new form of computer that manipulates information in a vastly different and more powerful way than a conventional computer. Sufficiently large quantum computers can solve problems intractable on any type of non-quantum ("classical") hardware. For example, a quantum computer would be able to simulate the physics or chemistry of complex problems impossible to model on a classical super-computer. This would profoundly impact scientific research, and allow access to regimes that are currently beyond experimental or theoretical reach; for example in quantum chemistry, or condensed matter physics. Despite 20 years of experimental work on quantum computing, a quantum processor with such computational power has remained beyond the reach of experiments. Recent progress in trapped-ion techniques means that such a machine is now attainable in the time-frame of this project. In recent years a variety of technologies has been used to show that the building blocks of a quantum computer can work well enough to perform useful real-world computations. The challenge now, for all technologies, is to develop systems with a large number of qubits (quantum bits, the basic unit of information in a quantum computer) possessing the qubit-to-qubit connectivity which is essential for quantum computing, while minimizing operation errors. The eventual aim for this field is to build processors containing hundreds of thousands of effectively perfect qubits all connected by high precision quantum logic gates. Such a full scale quantum computer will change the 21st century in the same way as the classical computer changed the 20th century. However, building a processor this complex remains a formidable engineering challenge which will require significant resources and last for decades.The focus of this project is instead to try and aim for a realistic near-term goal. Using trapped atomic ions as qubits, and taking advantage of the high fidelity and high connectivity gates already proven with these qubits, we aim to make a processor with at least 50 qubits, with gate errors low enough to perform circuits of thousands of gates. Such an intermediate scale quantum processor is beyond the ability of even our most powerful classical supercomputers to mimic. With this processor, we aim to demonstrate the potential quantum computers have to solve real-world problems with a "quantum advantage". In addition, we aim to develop and to test noise-resilient methods to extract maximum performance from intermediate-scale processors, such as error mitigation protocols and hybrid quantum-classical algorithms. However, as the history of classical computing has shown us, with the ability to develop and to prototype new techniques on real quantum hardware the largest rewards may well come from unexpected directions. This project will deliver that hardware.