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arXiv 1312.6907quant-ph
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量子力学中的测量与遍历性

Measurement and Ergodicity in Quantum Mechanics

Mariano Bauer, Pier A. Mello

摘要:

单微观系统连续非破坏性测量的实验实现提出了量子力学中的遍历性问题。我们调查是否在一个实现一个单一的系统的时间平均相关的QM平均在一个合奏同样准备好的系统。我们采用了冯·诺依曼测量模型的推广,将系统耦合到$N$“探针”--具有我们可以支配的强度--并检测后者。该模型与量子电动力学腔的实验过程相似。由于耦合到探针的可观察到的本征值的概率的修改可以计算分析和结果比较定性以及与实验组获得的数值。我们发现,这个问题不是遍历的,除了在本征态的观察正在研究的情况下。

英文摘要:

The experimental realization of successive non-demolition measurements on single microscopic systems brings up the question of ergodicity in Quantum Mechanics (QM). We investigate whether time averages over one realization of a single system are related to QM averages over an ensemble of similarly prepared systems. We adopt a generalization of von Neumann model of measurement, coupling the system to $N$ "probes" --with a strength that is at our disposal-- and detecting the latter. The model parallels the procedure followed in experiments on Quantum Electrodynamic cavities. The modification of the probability of the observable eigenvalues due to the coupling to the probes can be computed analytically and the results compare qualitatively well with those obtained numerically by the experimental groups. We find that the problem is not ergodic, except in the case of an eigenstate of the observable being studied.

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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