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arXiv · 2504.18063

Observation of gauge field induced non-Hermitian helical skin effects

Yu-Hong Han·Yi Li·Jia-Hui Zhang·Yang Kou·Liantuan Xiao·Suotang Jia·Linhu Li·Feng Mei
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Abstract

Synthetic gauge fields and non-Hermitian skin effects are pivotal to topological phases and non-Hermitian physics, each recently attracting great interest across diverse research fields. Realizing skin effects typically require nonreciprocal couplings or on-site gain and loss. Here, we theoretically and experimentally report that, under gauge fields, reciprocal dissipative couplings can nontrivially give rise to an unprecedented nonreciprocal skin effect, hosting pseudospin degree of freedom and featuring helical transport, dubbed as the ``helical pseudospin skin effect". Before introducing the gauge fields, this model exhibits localized pseudospin edge modes and extended bulk modes, without skin effects. As the gauge field strength is applied from $0$ to $\pi$, we observe the emergence of two distinct pseudospin skin effects and their topological transitions: the hybrid-order and second-order helical pseudospin skin effects. Our findings not only highlight gauge field enriched non-Hermitian topology, but also brings pseudospin-momentum locking into skin effects.

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Yu-Hong Han, Yi Li, Jia-Hui Zhang, Yang Kou, Liantuan Xiao, Suotang Jia, Linhu Li, Feng Mei. 2025-04-25. Observation of gauge field induced non-Hermitian helical skin effects. https://arxiv.org/abs/2504.18063

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