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arXiv · 2409.00378

Dynamic Moir\'{e}-like pattern in non-Hermitian Wannier-Stark ladder system

H. P. Zhang·Z. Song
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Abstract

We study the dynamical behavior of the non-Hermitian Wannier-Stark ladder system, which is a non-Hermitian Su-Schrieffer-Heeger chain with a position-dependent real potential. In the presence of a linear external field, we employ the non-Hermitian Floquet method and find that the energy levels are sensitive to the field. The system exhibits two distinct dynamic behaviors separated by an exceptional point: one in the $\mathcal{PT}$ symmetrical region associated with two real Wannier-Stark ladders, and another in the $\mathcal{PT}$\ symmetry-breaking region associated with complex conjugate ladders. As the boundary between the two regions, two ladders coalesce into a single ladder. In the case of a non-linear field, these two distinct regions appear alternately along the chain, exhibiting dynamic Moir\'{e}-like patterns.

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H. P. Zhang, Z. Song. 2024-08-31. Dynamic Moir\'{e}-like pattern in non-Hermitian Wannier-Stark ladder system. https://doi.org/10.1016/j.aop.2025.170049

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