论文标题
准颗粒，平坦带和流体动物的熔化
Quasiparticles, Flat Bands, and the Melting of Hydrodynamic Matter
论文作者
论文摘要
准颗粒的概念 - 长寿命的低能颗粒样激发 - 已成为凝结量子物质的键性，它解释了各种新兴的多体现象，例如超流体和超导性。在这里，我们使用准颗粒来解释在二维中流体动力相互作用粒子的经典系统的集体行为。在此问题的无序阶段，测量结果揭示了长寿命粒子对的亚群。有序结晶相的建模和仿真将对识别为准颗粒，并在光谱的狄拉克锥处出现。准颗粒刺激超音速配对雪崩，从而导致晶体的融化。在六角形晶体中，流体动力相互作用的固有三倍对称性与晶体的对称性相匹配，光谱形成了一个平坦的带，具有超低的低频声子，其集体相互作用会导致较尖锐的融化过渡。总的来说，这些发现证明了量子问题理论中概念在理解经典耗散环境中多体物理学方面的有用性。
The concept of quasiparticles -- long-lived low-energy particle-like excitations -- has become a keystone of condensed quantum matter, where it explains a variety of emergent many-body phenomena, such as superfluidity and superconductivity. Here, we use quasiparticles to explain the collective behavior of a classical system of hydrodynamically interacting particles in two dimensions. In the disordered phase of this matter, measurements reveal a sub-population of long-lived particle pairs. Modeling and simulation of the ordered crystalline phase identify the pairs as quasiparticles, emerging at the Dirac cones of the spectrum. The quasiparticles stimulate supersonic pairing avalanches, bringing about the melting of the crystal. In hexagonal crystals, where the intrinsic threefold symmetry of the hydrodynamic interaction matches that of the crystal, the spectrum forms a flat band dense with ultra-slow, low-frequency phonons whose collective interactions induce a much sharper melting transition. Altogether, these findings demonstrate the usefulness of concepts from quantum matter theory in understanding many-body physics in classical dissipative settings.
