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arXiv · 2506.01383

Many-body critical non-Hermitian skin effect

Yi Qin·Yee Sin Ang·Ching Hua Lee·Linhu Li
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Abstract

Criticality in non-Hermitian systems unveils unique phase transitions and scaling behaviors beyond Hermitian paradigms, offering new insights into the interplay between gain/loss, non-reciprocity, and complex energy spectra. In this paper, we uncover a new class of many-body critical non-Hermitian skin effect (CSE) originating from the interplay between multiple non-Hermitian pumping channels and Hubbard interactions. In particular, criticality in the real-to-complex transitions can selectively emerge within the subspace of bound states or scattering states, as well as their interacting admixtures. These mechanisms possess no single-particle analog and can be diagnosed through a specially defined correlation function. As more particles are involved, higher-order CSEs naturally arise, with greatly enhanced effective coupling strengths and hence greater experimental accessibility. Our results reveal an enriched landscape of non-Hermitian critical phenomena in interacting many-body systems, and pave the way for investigating unconventional non-Hermitian criticality in the context of various interaction-induced particle clustering configurations.

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Yi Qin, Yee Sin Ang, Ching Hua Lee, Linhu Li. 2025-06-02. Many-body critical non-Hermitian skin effect. https://doi.org/10.1038/s42005-025-02448-9

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