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arXiv quant-ph/9805020quant-ph
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不完全数据的量子态重建

Quantum State Reconstruction From Incomplete Data

V. Buzek, G. Drobny, R. Derka, G. Adam, H. Wiedemann

摘要:

知与猜是量子力学测量理论中两个基本的认识论支柱。量子力学是一种统计理论。一般来说,先验未知状态可以完全确定,只有当测量的无穷系综相同准备的量子系统进行。但是,当只有不完整的数据可用(已知)时,如何估计(猜测)量子态呢?根据给定的测量数据,什么是最可靠的估计?假设只有有限数量的量子物体是相同准备的,那么什么是最佳测量?这些是我们要解决的一些问题。我们提出了几种从测量数据重建量子系统态的方案:(1)我们证明了如何有效地利用最大熵原理在不完全观测水平上估计量子态。(2)我们展示了如何贝叶斯推断可以用于重建的量子态时,只有有限数量的相同准备的系统进行测量。(3)我们描述的最佳广义测量的有限数量的相同准备的量子系统,其结果在估计的量子态具有最高的保真度。

英文摘要:

Knowing and guessing, these are two essential epistemological pillars in the theory of quantum-mechanical measurement. As formulated quantum mechanics is a statistical theory. In general, a priori unknown states can be completely determined only when measurements on infinite ensembles of identically prepared quantum systems are performed. But how one can estimate (guess) quantum state when just incomplete data are available (known)? What is the most reliable estimation based on a given measured data? What is the optimal measurement providing only a finite number of identically prepared quantum objects are available? These are some of the questions we address. We present several schemes for a reconstruction of states of quantum systems from measured data: (1) We show how the maximum entropy (MaxEnt) principle can be efficiently used for an estimation of quantum states on incomplete observation levels. (2) We show how Bayesian inference can be used for reconstruction of quantum states when only a finite number of identically prepared systems are measured. (3) We describe the optimal generalized measurement of a finite number of identically prepared quantum systems which results in the estimation of a quantum state with the highest fidelity.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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