AUTHOR=Wu Shi-Qiao , Xu Yadong , Jiang Jian-Hua 

TITLE=Tunable non‐Hermitian skin effects in Su‐Schrieffer‐Heeger‐like models

JOURNAL=Frontiers in Physics

VOLUME=Volume 11 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/physics/articles/10.3389/fphy.2023.1123596

DOI=10.3389/fphy.2023.1123596

ISSN=2296-424X

ABSTRACT=Skin effect is a well-known feature of non-Hermitian systems, in which the 
bulk states evolve from extended to localized toward system boundaries. In this work, 
we numerically reveal tunable non-Hermitian skin effects in one and two-dimensional
Su-Schrieffer-Heeger (SSH)-like tight-binding models. Their occurrence mainly relies 
on both of the non-reciprocal hoppings within and across the unit cells. Notably, we 
demonstrate that by engineering the non-reciprocal hopping configurations of lattice 
sites, the non-Hermitian skin modes can be predicted at expected edges or corners
irrespective of whether the system is topological or not. And they also have no relation 
with the concrete value of hopping terms but with their scaling factors. These tunable 
non-Hermitian skin effects and higher-order non-Hermitian skin effects can be 
exploited to guide waves into targeted regions and may have useful applications when 
realized in metamaterials