Characterizing Resources for Quantum Information

在过去的二十年里，研究人员已经意识到，管理微观世界的物理定律的独特特征，即量子物理定律，可以被利用来实现计算，通信和传感的变革性新能力。这一新兴领域被称为量子信息科学。 最近，实验能力和理论方法取得了巨大的进步，导致了量子计算的小规模演示，最多可达16个量子位，称为量子位。量子计算是非常强大的：只要50个量子比特多一点，量子计算机就可以执行传统计算机，甚至是今天最快的超级计算机都无法执行的计算任务。但量子计算也很脆弱。量子计算的输出可能会由于底层硬件或控制中非常小的缺陷而被破坏，这会产生新的错误，称为退相干，这在传统计算机中不会发生。利用量子世界的量子计算能力，这需要开发新的理论和实验工具来克服这些特殊类型的错误。 在过去的十年中，我的研究项目开创了理论框架和实用方法的发展，这些方法能够表征和抑制原型量子计算机中的各种类型的错误。通过我的研究项目开发的随机基准测试方法最近被采纳为错误表征的全球标准，并已被所有领先的量子计算研究小组应用。 随着原型量子计算机现在扩展到数十个量子比特，量子计算接近技术现实，表征其性能的挑战和重要性大大增加。我的研究将侧重于开发新的方法来表征集成量子计算电路的性能，并抑制一种特别有问题的错误类型，称为相干错误，这可能是实现强大量子计算的限制因素。 此外，迫切需要开发工具和概念，使研究界和工业界能够了解如何利用量子计算的力量解决各种社会重要问题，例如制药行业量子化学材料的模拟以及通过新形式的机器学习分析大数据。因此，我的研究项目旨在通过利用我的研究项目最近的主要结果来促进这一过程，在那里我们表明，对量子力学的一种非常古老的好奇心，与试图用经典变量描述量子系统时出现的特殊行为有关，似乎是量子系统的关键特征，通过量子计算实现新的进步。

Over the past two decades researchers have realized that the unique features of the laws of physics that govern the micro-world, namely the laws of quantum physics, can be harnessed to enable transformative new capabilities for computing, communicating and sensing. This emerging field is known as quantum information science. Recently there have been dramatic advances in experimental capabilities and theoretical methods leading to small scale demonstrations of quantum computing, with up to 16 quantum bits, called qubits. Quantum computing is very powerful: with a little more than 50 qubits, a quantum computer can perform computational tasks that no conventional computer, even today's fastest supercomputers, could perform. But quantum computing is also fragile. The output of a quantum computation can be spoiled due to very small imperfections in the underlying hardware or control, which create new kinds of errors, known as decoherence, which does not occur in conventional computers. Harnessing the capabilities of the quantum world for quantum computing this requires developing new theoretical and experimental tools to overcome these special kinds of errors. Over the past decade my research program pioneered the development of a theoretical framework and practical methods that enable the characterization and suppression of various types of errors in prototype quantum computers. The randomized benchmarking method developed through my research program has recently adopted as the global standard for error characterization and have been applied by all of the leading quantum computing research groups. As prototype quantum computers are now scaling up to dozens of qubits, and quantum computing approaches technological reality, the challenge and importance of characterizing their performance has substantially increased. My research will focus on developing new methods to characterize the performance of integrated quantum computing circuits and to suppress a particularly problematic type of error, known as a coherent error, which can be a limiting factor for achieving robust quantum computing. In addition, there is a strong need for developing tools and concepts that will enable both the research community and industry to understand how to harness the power of quantum computing for a wide variety of societally important problems, such as simulation of materials in quantum chemistry for the pharmaceutical industry and analyzing big data through new forms of machine learning. Thus my research project will aim to facilitate this process by leveraging a recent major result from my research program, where we showed that a very old curiosity about quantum mechanics, associated with peculiar behaviours that arise when attempting to describe quantum systems with classical variables, seems to be the key feature of quantum systems that enables new advances through quantum computing.