发表机构
Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area (Guangdong); Guangdong Provincial Key Laboratory of Quantum Metrology and Sensing & School of Physics and Astronomy, Sun Yat-Sen University (Zhuhai Campus)（粤港澳大湾区量子科学中心; 中山大学（珠海校区）物理与天文学院 广东省量子精密测量与传感重点实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究双链局域耦合的Hatano-Nelson链，发现强耦合下仍存在临界非厄米趋肤效应，通过局域杂化碎片化希尔伯特空间产生无标度趋肤态，开辟了非厄米临界行为的新途径。
AI 中文摘要
我们研究了两个 Hatano-Nelson 链中在由包含距离 $d$ 隔开的两个体点处局域耦合所产生的反常临界非厄米趋肤效应（CNHSE）。尽管传统 CNHSE 通常与弱耦合子系统相关，但我们系统中的临界行为在强链间耦合区域持续存在。强局域杂化产生高能杂质模，并有效将低能希尔伯特空间碎片化为几何选择的扇区，其中一个扇区支持无标度趋肤态。独立地，外扇区中选择的态数目对双链系统遵循 $2(L-d)$。这些结果确立了局域耦合诱导的碎片化作为超越弱耦合范式的临界非厄米行为的一种途径。
英文摘要
We investigate the critical non-Hermitian skin effect (CNHSE) and the coupling-driven morphing of scale-free localization (SFL) in two Hatano-Nelson chains coupled locally at two bulk sites separated by an inclusive distance d. At weak interchain coupling, competition between the opposite skin accumulations of the two chains generates a geometrically selected critical branch with a complex loop-like spectrum and scale-free skin states localized near the physical boundaries. Remarkably, this SFL branch persists as the coupling becomes strong, although its underlying mechanism and spatial profile change qualitatively. Strong local hybridization generates high-energy impurity states and effectively divides the low-energy Hilbert space into geometry-selected inner and outer segments, with the former supporting SFL states near the interchain-coupled sites and the latter retaining conventional skin states. The number and localization scale of the SFL states are controlled by the separation between the coupling sites. Consequently, increasing the interchain coupling continuously relocates the SFL states from the physical boundaries to the coupling-defined internal interfaces. Our results demonstrate that bilocal coupling can induce a CNHSE and further drive its scale-free states into a segmentation-induced localization regime.
Comments12 pages, 9 figures
