Weijin Chen

Dec 19, 2024 | science.org | Guoqiang Xu |Xue Zhou |Weijin Chen |Guangwei Hu |Zhiyuan Yan |Zhipeng Li | +2 more

Published In ScienceVolume 386 | Issue 672820 December 2024Article versionsSubmission historyReceived: 5 May 2024Accepted: 4 November 2024Published in print: 20 December 2024PermissionsRequest permissions for this article. AcknowledgmentsFunding: This work was funded by the Ministry of Education, Republic of Singapore Ministry of Education, grant no.

Jun 8, 2023 | link.aps.org | Mengqi Liu |Shanghai Jiao Tong |Weijin Chen |Guangwei Hu

Abstract Perfect absorbers, which can achieve total absorption of all incoming energy, have been extensively studied in the last decades for various important technologies in general wave systems. Here, we show that perfect absorption (PA) is generically associated with topological spectral phase singularity (SPS), carrying conserved and tunable quantized topological invariants in spectral space. The order of topological invariant ṽ depends on the number of degenerate outgoing channels.