Topological exceptional surfaces in non-Hermitian systems with parity-time and parity-particle-hole symmetries
Topological exceptional surfaces in non-Hermitian systems with parity-time and parity-particle-hole symmetries
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DOI：
10.1103/physrevb.99.041202
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发表时间：
2019-01-24
影响因子：
3.7
通讯作者：
Yokoyama, Takehito
中科院分区：
文献类型：
--
作者：
Okugawa, Ryo;Yokoyama, Takehito
研究了具有宇称-时间（PT）和宇称-粒子-空穴（CP）对称性的非厄米特系统的拓扑带简并。在d维非厄米特系统中，由于PT或CP对称性，（d - 1）维例外曲面可以从带接触中出现。我们研究了由于带简并而导致的例外曲面的拓扑稳定性和零能隙准粒子。我们还证明了带简并通过使用拓扑半金属和超导体的晶格模型。
We study a topological band degeneracy in non-Hermitian systems with parity-time (PT) and parity-particle-hole (CP) symmetries. In d-dimensional non-Hermitian systems, it is shown that (d - 1)-dimensional exceptional surfaces can appear from band touching thanks to PT or CP symmetry. We investigate the topological stability and zero-gap quasiparticles for the exceptional surfaces due to the band degeneracy. We also demonstrate the band degeneracy by using lattice models of a topological semimetal and a superconductor.