Topological semimetal phase with exceptional points in one-dimensional non-Hermitian systems
Topological semimetal phase with exceptional points in one-dimensional non-Hermitian systems
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DOI：
10.1103/physrevresearch.2.043045
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发表时间：
2020-01
期刊：
影响因子：
--
通讯作者：
Kazuki Yokomizo;S. Murakami
中科院分区：
文献类型：
--
作者：
Kazuki Yokomizo;S. Murakami
为了描述非厄米晶体系统的本征态，近年来建立了非布洛赫带理论，广义布里色带具有厄米系统所没有的独特特征。在这篇论文中，我们证明了在具有亚晶格对称性和时间反转对称性的一维非厄米系统中，具有异常点的拓扑半金属相是稳定的。这源于GBZ的独特功能。我们可以将异常点的运动与表征拓扑绝缘子相位的拓扑不变量值的变化联系起来。还表明，根据本征态的对称性，能带被划分为三个区域。
To describe eigenstates in non-Hermitian crystalline systems, the non-Bloch band theory has recently been established, and the generalized Brillouin zone (GBZ) has unique features which are absent in Hermitian systems. In this Letter, we show that in one-dimensional non-Hermitian systems with both sublattice symmetry and time-reversal symmetry, a topological semimetal phase with exceptional points is stable. This stems from the unique features of the GBZ. We can relate the motion of the exceptional points with the change of the value of a topological invariant characterizing a topological insulator phase. It is also shown that the energy bands are divided into three region, depending on the symmetry of the eigenstates.