Hydrodynamic moiré superlattice

• 成果类型: Article
• 署名作者: Xu, Guoqiang; Zhou, Xue; Chen, Weijin; Hu, Guangwei; Yan, Zhiyuan; Li, Zhipeng; Yang, Shuihua; Qiu, Cheng-Wei
• 署名单位: National University of Singapore; Chongqing Technology & Business University; Nanyang Technological University
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-9357
• DOI: 10.1126/science.adq2329
• 发表日期: 2024-12-20
• 页码: 1377-1383
• 关键词: graphene; light

摘要

The structural periodicity in photonic crystals guarantees the crystal's effective energy band structure, which is the fundamental cornerstone of topological and moir & eacute; physics. However, the shear modulus in most fluids is close to zero, which makes it challenging for fluids to maintain spatial periodicity akin to photonic crystals. We realized periodic vortices in hydrodynamic metamaterials and created a bilayer moir & eacute; superlattice by stacking and twisting two such vortex fluids. We observed energy delocalization and localization when the twist angles, respectively, result in the Pythagorean and non-Pythagorean triples in the fluidic moir & eacute; superlattice. Anomalous localization was found even in commensurate moir & eacute; fluids with large lattice constants that satisfy Pythagorean triples. Our work reports the moir & eacute; phenomena in fluids and opens an unexpected door to controlling the energy transfer, mass transport, and particle navigation through the elaborate dynamics of vortices in fluidic moir & eacute; superlattices.