Quantum Measurement and Control
Quantum Measurement and Control
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DOI：
10.1088/0264-9381/27/24/249002
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发表时间：
2010-12
影响因子：
3.5
通讯作者：
C. Kiefer
中科院分区：
文献类型：
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作者：
C. Kiefer
在过去的二十年里，单量子系统的实验研究取得了巨大的进展。这一进展涵盖量子光学、量子计算、量子密码学和量子计量学等领域，这些领域有时被概括为“量子技术”。其中一个关键问题是纠缠，它可以被认为是量子理论的特征。尽管这些不同的领域可能是不同的，但它们都必须处理测量过程的量子力学处理，特别是控制过程。作者认为，量子控制是“设计需要量子力学知识的控制”。在重要步骤进行测量的量子控制情况称为量子系统的反馈（或前馈）控制，在这里起着核心作用。这本书提出了一个全面的和可访问的理论工具，需要科普这些情况的治疗。它还为读者提供了有关实验发展的必要背景信息。两位作者都是这一领域的专家，他们做出了重大贡献。在介绍了量子测量理论和量子参数估计的一章之后，开放量子系统的中心议题将被详细讨论。本章包括主方程的推导，林德布拉德形式的讨论，以及退相干-通过与环境的相互作用经典性质的不可逆出现。一个单独的章节是专门描述开放系统的方法的量子轨迹。两章然后处理量子反馈控制的中心主题，而最后一章给出了一个简明的介绍的中心应用之一-量子信息。所有部分都包含一系列练习，这些练习是学习材料的有用工具。特别有帮助的还有各种单独的框，这些框提供了关于块表示或反馈增益-带宽关系等主题的重要背景材料。关于量子力学和相空间以及随机微分方程的两个附录也是为了达到同样的目的。正如作者所强调的那样，这本书的目标读者是物理学家和已经熟悉量子力学的控制工程师。它采取了一种可操作的方法，并提供了跟踪量子技术研究所需的所有材料。另一方面，一些概念性的问题，如测量过程与量子理论解释的相关性，却被忽略了。对此感兴趣的读者可以参考一下教科书，比如马克西米利安·施洛斯豪尔的《退相干与量子到经典的转变》。虽然本书不包含引力的应用，但它的部分内容可能与引力波探测和量子引力现象学的物理学有关。在这方面，它也应该是本杂志的读者感兴趣的。
In the last two decades there has been an enormous progress in the experimental investigation of single quantum systems. This progress covers fields such as quantum optics, quantum computation, quantum cryptography, and quantum metrology, which are sometimes summarized as `quantum technologies'. A key issue there is entanglement, which can be considered as the characteristic feature of quantum theory. As disparate as these various fields maybe, they all have to deal with a quantum mechanical treatment of the measurement process and, in particular, the control process. Quantum control is, according to the authors, `control for which the design requires knowledge of quantum mechanics'. Quantum control situations in which measurements occur at important steps are called feedback (or feedforward) control of quantum systems and play a central role here. This book presents a comprehensive and accessible treatment of the theoretical tools that are needed to cope with these situations. It also provides the reader with the necessary background information about the experimental developments. The authors are both experts in this field to which they have made significant contributions. After an introduction to quantum measurement theory and a chapter on quantum parameter estimation, the central topic of open quantum systems is treated at some length. This chapter includes a derivation of master equations, the discussion of the Lindblad form, and decoherence – the irreversible emergence of classical properties through interaction with the environment. A separate chapter is devoted to the description of open systems by the method of quantum trajectories. Two chapters then deal with the central topic of quantum feedback control, while the last chapter gives a concise introduction to one of the central applications – quantum information. All sections contain a bunch of exercises which serve as a useful tool in learning the material. Especially helpful are also various separate boxes presenting important background material on topics such as the block representation or the feedback gain-bandwidth relation. The two appendices on quantum mechanics and phase-space and on stochastic differential equations serve the same purpose. As the authors emphasize, the book is aimed at physicists as well as control engineers who are already familiar with quantum mechanics. It takes an operational approach and presents all the material that is needed to follow research on quantum technologies. On the other hand, conceptual issues such as the relevance of the measurement process for the interpretation of quantum theory are neglected. Readers interested in them may wish to consult instead a textbook such as Decoherence and the Quantum-to-Classical Transition by Maximilian Schlosshauer. Although the present book does not contain applications to gravity, part of its content might become relevant for the physics of gravitational-wave detection and quantum gravity phenomenology. In this respect it should be of interest also for the readers of this journal.