Non-Hermitian quasicrystal in dimerized lattices  

作　　者：Longwen Zhou Wenqian Han 周龙文;韩雯岍(College of Physics and Optoelectronic Engineering,Ocean University of China,Qingdao 266100,China)

机构地区：[1]College of Physics and Optoelectronic Engineering,Ocean University of China,Qingdao 266100,China

出　　处：《Chinese Physics B》2021年第10期56-65,共10页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.11905211);the China Postdoctoral Science Foundation(Grant No.2019M662444);the Fundamental Research Funds for the Central Universities,China(Grant No.841912009);the Young Talents Project at Ocean University of China(Grant No.861801013196);the Applied Research Project of Postdoctoral Fellows in Qingdao(Grant No.861905040009)。

摘　　要：Non-Hermitian quasicrystals possess PT and metal-insulator transitions induced by gain and loss or nonreciprocal effects.In this work,we uncover the nature of localization transitions in a generalized Aubry-Andre-Harper model with´dimerized hopping amplitudes and complex onsite potential.By investigating the spectrum,adjacent gap ratios and inverse participation ratios,we find an extended phase,a localized phase and a mobility edge phase,which are originated from the interplay between hopping dimerizations and non-Hermitian onsite potential.The lower and upper bounds of the mobility edge are further characterized by a pair of topological winding numbers,which undergo quantized jumps at the boundaries between different phases.Our discoveries thus unveil the richness of topological and transport phenomena in dimerized non-Hermitian quasicrystals.

关 键 词：non-Hermitian system QUASICRYSTAL LOCALIZATION topological phase 

分 类 号：O469[理学—凝聚态物理]