近日，新加坡国立大学的Cheng-Wei Qiu及其研究团队取得一项新进展。经过不懈努力，他们对流体动力学莫尔超晶格进行研究。相关研究成果已于2024年12月20日在国际权威学术期刊《科学》上发表。

该研究团队在流体超材料中实现了周期性涡旋，并通过堆叠和扭转两种这样的涡旋流体，创建了一个双层莫尔超晶格。研究人员观察到，当扭转角度分别导致流体莫尔超晶格中形成勾股数和非勾股数时，能量会出现离域和局域现象。

即使在满足勾股数且具有大晶格常数的相称莫尔流体中，也发现了异常局域化现象。这项研究工作报道了流体中的莫尔现象，并为通过流体莫尔超晶格中涡旋的精细动力学来控制能量传递、质量输运和粒子导航开辟了一条意想不到的新途径。

据悉，光子晶体中的结构周期性确保了晶体有效的能带结构，这是拓扑物理和莫尔纹物理的基本基石。然而，大多数流体的剪切模量接近于零，这使得流体难以维持类似于光子晶体的空间周期性。

附：英文原文

Title: Hydrodynamic moiré superlattice

Author: Guoqiang Xu, Xue Zhou, Weijin Chen, Guangwei Hu, Zhiyuan Yan, Zhipeng Li, Shuihua Yang, Cheng-Wei Qiu

Issue&Volume: 2024-12-20

Abstract: The structural periodicity in photonic crystals guarantees the crystal’s effective energy band structure, which is the fundamental cornerstone of topological and moiré 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 moiré 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 moiré superlattice. Anomalous localization was found even in commensurate moiré fluids with large lattice constants that satisfy Pythagorean triples. Our work reports the moiré 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 moiré superlattices.

DOI: 10.1126/science.adq2329

Source: https://www.science.org/doi/10.1126/science.adq2329

来源：科学网  小柯机器人