arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0911.4307quant-ph
收藏

非理想环境中的量子达尔文主义

Quantum Darwinism in non-ideal environments

Michael Zwolak, H. T. Quan, Wojciech H. Zurek

摘要:

量子达尔文主义提供了一个信息理论框架,用于从量子基底中出现客观的经典世界。这种出现的关键是冗余信息在整个环境中的扩散,然后观察者可以拦截它。我们研究了当环境E处于非理想状态(例如,混合)初始状态。在良好的退相干的情况下,也就是说,在指针状态被明确地选择之后,系统S和环境片段F之间的互信息仅由F的熵增加给出。这表明环境记录S状态的能力与其增加熵的能力直接相关。在与S的相互作用下保持几乎不变的环境,因为它们具有大的初始熵或未对准的初始状态,因此具有减弱的获取信息的能力。为了阐明好的退相干的概念,我们证明了-当退相干不完全时-互信息与F的熵变的偏差由量子不和谐量化,即,S和F之间的过量互信息是关于S的指针状态之间的初始相干性的信息。除了用单量子比特系统与多量子比特环境相互作用来说明这些结果之外,我们还发现了环境所获得的信息冗余度的标度关系,该标度关系显示出与S的初始状态无关的普遍行为。我们的研究结果表明,量子达尔文主义是强大的非理想的初始状态的环境:环境几乎总是获取冗余信息的系统,但它的收购率可以降低。

英文摘要:

Quantum Darwinism provides an information-theoretic framework for the emergence of the objective, classical world from the quantum substrate. The key to this emergence is the proliferation of redundant information throughout the environment where observers can then intercept it. We study this process for a purely decohering interaction when the environment, E, is in a non-ideal (e.g., mixed) initial state. In the case of good decoherence, that is, after the pointer states have been unambiguously selected, the mutual information between the system, S, and an environment fragment, F, is given solely by F's entropy increase. This demonstrates that the environment's capacity for recording the state of S is directly related to its ability to increase its entropy. Environments that remain nearly invariant under the interaction with S, either because they have a large initial entropy or a misaligned initial state, therefore have a diminished ability to acquire information. To elucidate the concept of good decoherence, we show that - when decoherence is not complete - the deviation of the mutual information from F's entropy change is quantified by the quantum discord, i.e., the excess mutual information between S and F is information regarding the initial coherence between pointer states of S. In addition to illustrating these results with a single qubit system interacting with a multi-qubit environment, we find scaling relations for the redundancy of information acquired by the environment that display a universal behavior independent of the initial state of S. Our results demonstrate that Quantum Darwinism is robust with respect to non-ideal initial states of the environment: the environment almost always acquires redundant information about the system but its rate of acquisition can be reduced.

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。

↑