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arXiv · 2306.04460

Loss-induced Floquet non-Hermitian skin effect

Yaohua Li·Cuicui Lu·Shuang Zhang·Yong-Chun Liu
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Abstract

Non-Hermitian topological systems have attracted lots of interest due to their unique topological properties when the non-Hermitian skin effect (NHSE) appears. However, the experimental realization of NHSE conventionally requires non-reciprocal couplings, which are compatible with limited systems. Here we propose a mechanism of loss-induced Floquet NHSE, where the loss provides the basic source of non-Hermicity and the Floquet engineering brings about the Floquet-induced complex next-nearest-neighbor couplings. We also extend the generalized Brillouin zone theory to nonequilibrium systems to describe the Floquet NHSE. Furthermore, we show that this mechanism can realize the second-order NHSE when generalized to two-dimensional systems. Our proposal can be realized in photonic lattices with helical waveguides and other related systems, which opens the door for the study of topological phases in Floquet non-Hermitian systems.

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Yaohua Li, Cuicui Lu, Shuang Zhang, Yong-Chun Liu. 2023-06-07. Loss-induced Floquet non-Hermitian skin effect. https://doi.org/10.1103/physrevb.108.l220301

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