arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2004.00912physics.optics
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非厄米特系统的非对称散射矩阵

Unambiguous scattering matrix for non-Hermitian systems

Andrey Novitsky, Dmitry Lyakhov, Dominik Michels, Alexander Pavlov, Alexander Shalin, Denis Novitsky

摘要:

$\mathcal{PT}$对称性是一个独特的平台,光操纵和多用途的单向不可见性,激光,传感等破碎和未破碎的$\mathcal{PT}$对称状态在非厄米开放系统中描述的散射矩阵。多层结构作为开放系统的一个最简单的例子,没有散射矩阵的确定定义,因为输出端口可以被置换。$\mathcal{PT}$ -对称和$\mathcal{PT}$ -对称破缺状态的例外点定义的不确定性是一个重要的问题,因为例外点在传感和模式识别等应用中是必不可少的。这里我们从$\mathcal{PT}$ -对称哈密顿量和散射矩阵之间的明确关系导出适当的散射矩阵。我们揭示了具有排列输出端口的散射矩阵的例外点与$\mathcal{PT}$对称性破缺无关。然而,它们可以用来寻找一个激光的开始,在我们的时域计算和散射矩阵极点分析证明。我们的结果对于非厄米系统的各种应用包括环绕例外点、相干完全吸收、$\mathcal{PT}$对称等离子体等都有重要意义。

英文摘要:

$\mathcal{PT}$ symmetry is a unique platform for light manipulation and versatile use in unidirectional invisibility, lasing, sensing, etc. Broken and unbroken $\mathcal{PT}$-symmetric states in non-Hermitian open systems are described by scattering matrices. A multilayer structure, as a simplest example of the open system, has no certain definition of the scattering matrix, since the output ports can be permuted. The uncertainty in definition of the exceptional points bordering $\mathcal{PT}$-symmetric and $\mathcal{PT}$-symmetry-broken states poses an important problem, because the exceptional points are indispensable in applications as sensing and mode discrimination. Here we derive the proper scattering matrix from the unambiguous relation between the $\mathcal{PT}$-symmetric Hamiltonian and scattering matrix. We reveal that the exceptional points of the scattering matrix with permuted output ports are not related to the $\mathcal{PT}$ symmetry breaking. Nevertheless, they can be employed for finding a lasing onset as demonstrated in our time-domain calculations and scattering-matrix pole analysis. Our results are important for various applications of the non-Hermitian systems including encircling exceptional points, coherent perfect absorption, $\mathcal{PT}$-symmetric plasmonics, etc.

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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