标题： 无序非厄米电路上杂质诱导的无标度局域化观测 显示英文标题

标题： Observation of Impurity-Induced Scale-Free Localization in a Disordered Non-Hermitian Electrical Circuit

摘要： 非厄米系统的一个独特特性是其对边界条件的极端敏感性，例如在开放边界条件下出现非厄米皮肤效应（NHSE），其中大部分体态会局域在边界上。在存在杂质的情况下，可以出现无尺度局域化，这与NHSE在本质上不同。在这里，我们设计了一个存在单个非厄米杂质和非互易跃迁的无序非厄米电路上的实验。我们观察到本征态的异常无尺度积累，方向与体跃迁方向相反。实验结果为进一步探索非厄米电路中的异常皮肤效应打开了大门。 显示英文摘要

摘要： One of unique features of non-Hermitian systems is the extreme sensitive to their boundary conditions, e.g., the emergence of non-Hermitian skin effect (NHSE) under the open boundary conditions, where most of bulk states become localized at the boundaries. In the presence of impurities, the scale-free localization can appear, which is qualitatively distinct from the NHSE. Here, we experimentally design a disordered non-Hermitian electrical circuits in the presence of a single non-Hermitian impurity and the nonreciprocal hopping. We observe the anomalous scale-free accumulation of eigenstates, opposite to the bulk hopping direction. The experimental results open the door to further explore the anomalous skin effects in non-Hermitian electrical circuits.