Topological non-Hermitian skin effect

Abstract

This article reviews recent developments in the non-Hermitian skin effect (NHSE), particularly on its rich interplay with topology. The review starts off with a pedagogical introduction on the modified bulk-boundary correspondence, the synergy and hybridization of NHSE and band topology in higher dimensions, as well as, the associated topology on the complex energy plane such as spectral winding topology and spectral graph topology. Following which, emerging topics are introduced such as non-Hermitian criticality, dynamical NHSE phenomena, and the manifestation of NHSE beyond the traditional linear non-interacting crystal lattices, particularly its interplay with quantum many-body interactions. Finally, we survey the recent demonstrations and experimental proposals of NHSE.

Graphical abstract

Keywords

non-Hermitian skin effect / topological phases

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Competing interests

The authors declare that they have no competing interests.

Acknowledgements

C. H. Lee acknowledges support from Singapore NRF’s QEP2.0 grant (NRF2021-QEP2-02-P09) and MOE Tier-1 grant (WBS: A-8000022-00-00). L. Li acknowledges support from National Natural Science Foundation of China (Grant No. 12104519) and the Guangdong Project (Grant No. 2021QN02X073).

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