Observation of scale-free localized states induced by non-Hermitian defects
Abstract
Wave localization is a fundamental phenomenon that appears universally in both natural materials and artificial structures and plays a crucial role in understanding the various physical properties of a system. Usually, a localized state has an exponential profile with a localization length independent of the system size. Here, we experimentally demonstrate a new class of localized states called scale-free localized states, which has an unfixed localization length scaling linearly with the system size. Using circuit lattices, we observe that a non-Hermitian defect added to a Hermitian lattice induces an extensive number of states with scale-free localization. Furthermore, we demonstrate that, in a lattice with a parity-time-symmetric non-Hermitian defect, the scale-free localization emerges because of spontaneous parity-time symmetry breaking. Our results uncover a new type of localized states and extend the study of defect physics to the non-Hermitian regime.
Keywords
Cite
@article{arxiv.2402.04716,
title = {Observation of scale-free localized states induced by non-Hermitian defects},
author = {Xinrong Xie and Gan Liang and Fei Ma and Yulin Du and Yiwei Peng and Erping Li and Hongsheng Chen and Linhu Li and Fei Gao and Haoran Xue},
journal= {arXiv preprint arXiv:2402.04716},
year = {2024}
}