PT-breaking threshold in spatially asymmetric Aubry-Andre and Harper models: Hidden symmetry and topological states

被引：70

作者：

Harter, Andrew K. ^{[1
]}

Lee, Tony E. ^{[1
]}

Joglekar, Yogesh N. ^{[1
]}

机构：

[1] Indiana Univ Purdue Univ, Dept Phys, Indianapolis, IN 46202 USA

来源：

PHYSICAL REVIEW A | 2016年 / 93卷 / 06期

基金：

美国国家科学基金会;

关键词：

NON-HERMITIAN HAMILTONIANS; BEAM-PROPAGATION METHOD; PARITY-TIME SYMMETRY; PHOTONIC LATTICES; REAL SPECTRA; SOLITONS; LASER;

D O I：

10.1103/PhysRevA.93.062101

中图分类号：

O43 [光学];

学科分类号：

070207 ; 0803 ;

摘要：

Aubry-Andre-Harper lattice models, characterized by a reflection-asymmetric sinusoidally varying nearest-neighbor tunneling profile, are well known for their topological properties. We consider the fate of such models in the presence of balanced gain and loss potentials +/- i gamma located at reflection-symmetric sites. We predict that these models have a finite PT-breaking threshold only for specific locations of the gain-loss potential and uncover a hidden symmetry that is instrumental to the finite threshold strength. We also show that the topological edge states remain robust in the PT-symmetry-broken phase. Our predictions substantially broaden the possible experimental realizations of a PT-symmetric system.

引用

页数：7

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