Quantum Foundations in the Light of Quantum Information

如何理解量子系统的非经典概率行为的问题是爱因斯坦和玻尔之间悬而未决的争论的主题。他们对立的哲学观点之间的对立为物理学家和物理学哲学家之间关于从经典力学到量子力学转换的概念意义的持续辩论提供了紧张的气氛，争论的焦点是理论基础中的一个测量问题。20世纪90年代见证了量子信息理论的发展，人们意识到量子系统的某些非经典特征可以被利用来执行在牛顿世界中不可能完成的信息处理任务。这导致了人们对量子计算和量子密码学的理论和实践应用的兴趣激增，并重新考虑了玻尔-爱因斯坦债务背后的基本问题。智力价值：PI最近发表了一些关于这些问题的论文，特别是一篇论文(与罗布·克利夫顿和汉斯·哈尔沃森合著)，表明人们可以从三个信息论约束中推导出物理系统的量子理论描述的基本特征。这项研究项目涉及根据克利夫顿-布布-哈尔沃森的结果制定量子力学的信息论解释的细节。一个核心特征是把测量问题分成关于真理的问题和关于概率的问题，把真实的问题放在一边。概率问题的PI解包括：(I)人们可以从量子力学中推导出测量仪器作为经典信息源的存在条件，以及具有使用测量仪器应用和测试量子力学的能力的信息收集者的存在条件，以及(Ii)可以给出理论的广义跃迁概率的主观贝叶斯解释，而不解决测量的真理问题。PI认为真理问题的可能解决方案是众所周知的，并提议证明任何这样的解决方案产生的量子力学修正在解释性和方法论上都不如标准理论，特别是在解释量子计算和量子密码学的新结果方面。广泛影响：PI建议写一本书，发展这些概念，供从事量子信息和计算问题的科学家、致力于解释问题的科学研究人员以及对物理学基础发展感兴趣的更广泛的读者使用。国际物理所应邀在各种会议上发表与上述量子力学的信息论解释有关的论文，并向几本手册和百科全书投稿。最近的一些论文和博士论文讨论了Clifton-Bub-Halvorson结果及其影响，其中三名PI博士学生将在不久的将来撰写关于量子信息各个方面的论文。这项研究的结果将被纳入面向物理专业学生的一门本科物理哲学课程(PHIL 354)。PI还将通过一年一度的“物理学基础新方向会议”和在线档案来传播有关该项目的信息。1

Project SummaryThe problem of how to make sense of the non-classical probabilistic behavior ofquantum systems was the subject of an unresolved dispute between Einstein and Bohr.The opposition between their opposing philosophical views has provided the tension foran ongoing debate among physicists and philosophers of physics about the conceptualsignificance of the transition from classical to quantum mechanics, centering on a measurementproblem in the foundations of the theory. The 1990s saw the development ofa quantum theory of information, prompted by the realization that certain nonclassicalfeatures of quantum systems could be exploited to perform information-processing tasksthat would be impossible in a Newtonian world. This has led to an explosion of interestin theoretical and practical applications of quantum computation and quantum cryptography,and a reconsideration of the foundational problems underlying the Bohr-Einsteindebate.Intellectual Merit: The PI has published a number of recent papers on these issues,in particular a paper (jointly authored with Rob Clifton and Hans Halvorson) showingthat one can derive the basic features of a quantum-theoretic description of physical systemsfrom three information-theoretic constraints. The research project involves workingout the details of an information-theoretic interpretation of quantum mechanics inthe light of the Clifton-Bub-Halvorson result. A core feature is to split the measurementproblem into a problem about truth and a problem about probability, and to set aside thetruth problem. The PIs solution to the probability problem involves showing (i) that onecan derive from quantum mechanics the conditions for the existence of measuring instrumentsas sources of classical information, and the existence of information-gathererswith the ability to use measuring instruments to apply and test quantum mechanics, and(ii) that the generalized transition probabilities of the theory can be given a subjectiveBayesian interpretation without solving the truth problem of measurement. The PI arguesthat the possible solutions to the truth problem are well understood, and proposesto show that any such solution produces a modification of quantum mechanics that isexplanatorily and methodologically inferior to the standard theory, particularly with respectto accounting for the new results in quantum computation and quantum cryptography.Broader Impacts: The PI proposes to write a book developing these ideas accessibleto scientists who work on issues in quantum information and computation, tophilosophers of science who work on questions of interpretation, and to a wider groupof readers interested in developments in the foundations of physics. The PI has beeninvited to present papers on topics related to the above information-theoretic interpretationof quantum mechanics at various conferences, and to contribute articles to severalHandbooks and Encyclopedias. A number of recent papers and PhD dissertations discussthe Clifton-Bub-Halvorson result and its implications, and three of the PIs PhDstudents will shortly be working on dissertations on various aspects of quantum information.The results of this research will be incorporated in an undergraduate course onphilosophy of physics (Phil 354) directed at physics students. The PI will also disseminate information on the project through an annual "new directions in the foundations of physics conference," and through online archives. 1