Many-body critical non-Hermitian skin effect

Criticality in non-Hermitian systems unveils distinctive phase transitions and scaling behaviors beyond Hermitian paradigms. Here, we identify a class of many-body critical non-Hermitian skin effects (CSEs) arising from the interplay between multiple non-Hermitian pumping channels and Hubbard interactions, fundamentally distinct from the well-studied single-particle CSEs. In particular, criticality in real-to-complex transitions can selectively emerge within subspaces of bound or scattering states, as well as their interacting admixtures. We show that this effect is universal across different models and persists with increasing particle numbers, where higher-order CSEs naturally appear with strongly enhanced effective couplings, facilitating experimental accessibility. Our results reveal an enriched landscape of non-Hermitian critical phenomena in quantum many-body systems, driven by interaction-induced particle clustering, and open pathways for exploring unconventional non-Hermitian criticality in diverse experimental platforms. Non-Hermitian physics extends criticality beyond conventional Hermitian systems. Here, the authors report a universal many-body critical skin effect arising from the interplay of multiple pumping channels and interactions, revealing new collective edge phenomena and real-to-complex transitions.