机械波中的负能量流

IF 0.3 4区物理与天体物理 Q4 PHYSICS, MULTIDISCIPLINARY

Lithuanian Journal of Physics Pub Date : 2020-10-29 DOI:10.3952/physics.v60i4.4356

A. Matulis, A. Acus

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引用次数: 0

摘要

提出了一个类似于量子系统的经典系统，该系统具有概率流。该系统由一个由弹簧连接的质量链组成，并由其他弹簧连接到固定支架上。由于最后的弹簧，截止频率和色散出现在沿链传播的波的频谱中。研究表明，这种分散有助于能量回流的出现。在两个波干涉的情况下，这种回流的大小比上述量子问题中的概率回流值高一个数量级。考虑了格林函数方程，结果表明，当系统被两个连续的短脉冲激励时，能量回流也是可能的。这种经典的回流现象可以用强迫阻尼振荡器的结果所证实的能量流向局部模式的分支来解释。研究表明，即使在这样一个简单的系统中，也会发生能量回流（瞬时和平均）。

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Negative flow of energy in a mechanical wave

A classical system, which is analogous to the quantum one with a backﬂow of probability, is proposed. The system consists of a chain of masses interconnected by springs and attached by other springs to ﬁxed supports. Thanks to the last springs the cutoﬀ frequency and dispersion appears in the spectrum of waves propagating along the chain. It is shown that this dispersion contributes to the appearance of a backﬂow of energy. In the case of the interference of two waves, the magnitude of this backﬂow is an order of magnitude higher than the value of probability backﬂow in the mentioned quantum problem. The equation of Green’s function is considered and it is shown that the backﬂow of energy is also possible when the system is excited by two consecutive short pulses. This classical backﬂow phenomenon is explained by the branching of energy ﬂow to local modes that is conﬁrmed by the results for the forced damped oscillator. It is shown that even in such a simple system the backﬂow of energy takes place (both instantaneous and average).

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来源期刊

Lithuanian Journal of Physics 物理-物理：综合

CiteScore

0.90

自引率

16.70%

发文量

审稿时长

>12 weeks

期刊介绍： The main aim of the Lithuanian Journal of Physics is to reflect the most recent advances in various fields of theoretical, experimental, and applied physics, including: mathematical and computational physics; subatomic physics; atoms and molecules; chemical physics; electrodynamics and wave processes; nonlinear and coherent optics; spectroscopy.