标题： 非厄米声波边缘爆发 显示英文标题

标题： Non-Hermitian edge burst of sound

摘要： 非厄米能带拓扑可以产生在厄米系统中没有对应现象的现象。一个著名的例子是非厄米皮肤效应（NHSE），其中布洛赫本征态局域在边界上，这是由非平凡的谱绕数引起的。相反，对损耗性非厄米晶格的最新研究揭示了一种意外的边界局域损耗概率——这一现象不仅需要非厄米能带拓扑，还需要虚部（耗散）间隙的闭合。在这里，我们展示了在经典波超材料中出现的非厄米边缘爆发：一种损耗性非互易声学晶体。我们表明，当虚部间隙保持闭合时，边缘爆发可以在右侧边界、左侧边界或同时在两个边界发生，所有这些都在相同的非厄米能带拓扑下；后一种情况被称为双极边缘爆发。每种情况的发生取决于本征能谱中虚部间隙闭合点的数量和位置。这些发现将边缘爆发的概念从量子系统推广到经典波系统，将其确立为一种固有的材料特性，并丰富了非厄米系统中非厄米能带拓扑与其他物理性质之间复杂相互作用的物理内容。 显示英文摘要

摘要： Non-Hermitian band topology can give rise to phenomena with no counterparts in Hermitian systems. A well-known example is the non-Hermitian skin effect (NHSE), where Bloch eigenstates localize at a boundary, induced by a nontrivial spectrum winding number. In contrast, recent studies on lossy non-Hermitian lattices have uncovered an unexpected boundary-localized loss probability-a phenomenon that requires not only non-Hermitian band topology but also the closure of the imaginary (dissipative) gap. Here, we demonstrate the non-Hermitian edge burst in a classical-wave metamaterial: a lossy nonreciprocal acoustic crystal. We show that, when the imaginary gap remains closed, edge bursts can occur at the right boundary, left boundary, or both boundaries simultaneously, all under the same non-Hermitian band topology; the latter scenario is known as a bipolar edge burst. The occurrence of each scenario depends on the number and location of the imaginary gap closure points in the eigenenergy spectra. These findings generalize the concept of edge burst from quantum to classical wave systems, establish it as an intrinsic material property, and enrich the physics of the complex interplay between non-Hermitian band topology and other physical properties in non-Hermitian systems.