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arXiv 2007.08825cond-mat.dis-nncond-mat.mes-hallphysics.optics
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非厄米特开放系统的输运和谱特征

Transport and spectral features in non-Hermitian open systems

A. F. Tzortzakakis, K. G. Makris, A. Szameit, E. N. Economou

摘要:

我们研究了非厄米一维无序晶格的输运和光谱性质,其对角矩阵元素是随机复变量,同时取正(损失)和负(增益)虚值:它们的分布是通常的矩形分布或二元对相关分布,在厄米版本中,具有离域状态和不寻常的输运性质。与厄米特情形相反,我们的非厄米特系统中的所有态都是定域的。此外,本征值谱,为二进制配对相关的情况下,表现出一个意想不到的复杂的分形结构上的复杂的平面和增加非厄米特无序,本征值往往合并在特定的小面积的复杂平面,一个功能称为“本征值凝聚”。尽管强安德森局域化的所有本征态,该系统似乎表现出运输不是通过扩散,而是通过一个新的机制,通过突然跳跃之间的状态,即使在遥远的网站。这似乎是开放的非厄米特随机系统的一般特征。我们的研究结果的关系,最近的实验结果进行了讨论。

英文摘要:

We study the transport and spectral properties of a non-Hermitian one-dimensional disordered lattice, the diagonal matrix elements of which are random complex variables taking both positive (loss) and negative (gain) imaginary values: Their distribution is either the usual rectangular one or a binary pair-correlated one possessing, in its Hermitian version, delocalized states, and unusual transport properties. Contrary to the Hermitian case, all states in our non-Hermitian system are localized. In addition, the eigenvalue spectrum, for the binary pair-correlated case, exhibits an unexpected intricate fractallike structure on the complex plane and with increasing non-Hermitian disorder, the eigenvalues tend to coalesce in particular small areas of the complex plane, a feature termed "eigenvalue condensation". Despite the strong Anderson localization of all eigenstates, the system appears to exhibit transport not by diffusion but by a new mechanism through sudden jumps between states located even at distant sites. This seems to be a general feature of open non-Hermitian random systems. The relation of our findings to recent experimental results is also discussed.

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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