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arXiv 1602.05009cond-mat.mes-hallcond-mat.dis-nnphysics.comp-ph
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一维无序量子系统中的透射共振反常

Transmission Resonances Anomaly in 1D Disordered Quantum Systems

A. Eisenbach, Y. Bliokh, V. Freilkher, M. Kaveh, R. Berkovits

摘要:

在紧束缚模型的框架下研究了一维无序电子系统的电子本征态与电导率之间的联系。我们发现,弱无序只有部分的状态表现出共振传输,并有助于导电性。其余的特征值与透射峰无关,并且它们的波函数的振幅在样本内不表现出显著的最大值。此外,与普通状态不同,这些“隐藏”模式的寿命要么保持不变,甚至减少(取决于与铅的耦合)的混乱变得更强。在很宽的无序强度范围内,透射峰的数目与本征态的总数的平均比率与无序度无关,并且接近于在弱散射近似下解析导出的值$\sqrt{2/5}$。这些结果与光在一维随机非均匀介质中的光谱和输运性质完全相似,这提供了强有力的理由相信隐藏的非导电模式的存在是一维开放随机系统固有的普遍现象,并且它们在量子粒子和经典波的总态密度中的比例是相同的。

英文摘要:

Connections between the electron eigenstates and conductivity of one-dimensional disordered electron systems is studied in the framework of the tight-binding model. We show that for weak disorder only part of the states exhibit resonant transmission and contribute to the conductivity. The rest of the eigenvalues are not associated with peaks in transmission and the amplitudes of their wave functions do not exhibit a significant maxima within the sample. Moreover, unlike ordinary states, the lifetimes of these `hidden' modes either remain constant or even decrease (depending on the coupling with the leads) as the disorder becomes stronger. In a wide range of the disorder strengths, the averaged ratio of the number of transmission peaks to the total number of the eigenstates is independent of the degree of disorder and is close to the value $\sqrt{2/5}$, which was derived analytically in the weak-scattering approximation. These results are in perfect analogy to the spectral and transport properties of light in one-dimensional randomly inhomogeneous media, which provides strong grounds to believe that the existence of hidden, non-conducting modes is a general phenomenon inherent to 1D open random systems, and their fraction of the total density of states is the same for quantum particles and classical waves.

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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