近日，瑞典阿尔巴诺瓦大学的Ali W. Elshaari及其研究小组与瑞典斯德哥尔摩大学的Ivan M. Khaymovich等人合作并取得一项新进展。经过不懈努力，他们成功探测准周期镶嵌型晶格中的多重迁移率边。相关研究成果已于2024年9月26日在国际知名学术期刊《科学通报》上发表。

该研究团队利用精心设计的纳米光子电路中的准周期镶嵌型晶格，提供了实验证据来解答这些问题。该观察结果证明了在具有破缺对偶对称性和不同调制周期的晶格中，扩展态与局域态的共存。

通过单点注入和扫描无序程度，研究人员能够近似探测调制晶格的迁移率边。这些结果证实了最近的理论预测，为探索迁移率边物理开辟了一条新途径，并为使用混合集成光子器件进一步探索量子领域的迁移率边物理提供了灵感。

据悉，迁移率边（ME）是理解局域化物理的一个关键概念，它标志着能量谱中扩展态与局域态之间的临界转变。安德森局域化标度理论预测，在低维系统中不存在ME。因此，近年来，对精确ME的寻找，尤其是低维系统中单粒子的ME，在理论和实验研究中都引起了极大的兴趣，并取得了显著的进展。然而，仍有一些未解决的问题，包括单一系统是否可能展现多个ME，以及在强无序域中扩展态是否持续存在。

附：英文原文

Title: Probing multi-mobility edges in quasiperiodic mosaic lattices

Author: Jun Gao a , Ivan M. Khaymovich b c , Ali W. Elshaari a

Issue&Volume: 2024/09/26

Abstract: The mobility edge (ME) is a crucial concept in understanding localization physics, marking the critical transition between extended and localized states in the energy spectrum. Anderson localization scaling theory predicts the absence of ME in lower dimensional systems. Hence, the search for exact MEs, particularly for single particles in lower dimensions, has recently garnered significant interest in both theoretical and experimental studies, resulting in notable progress. However, several open questions remain, including the possibility of a single system exhibiting multiple MEs and the continual existence of extended states, even within the strong disorder domain. Here, we provide experimental evidence to address these questions by utilizing a quasiperiodic mosaic lattice with meticulously designed nanophotonic circuits. Our observations demonstrate the coexistence of both extended and localized states in lattices with broken duality symmetry and varying modulation periods. By single site injection and scanning the disorder level, we could approximately probe the ME of the modulated lattice. These results corroborate recent theoretical predictions, introduce a new avenue for investigating ME physics, and offer inspiration for further exploration of ME physics in the quantum regime using hybrid integrated photonic devices.

DOI: 10.1016/j.scib.2024.09.030

Source: https://www.sciencedirect.com/science/article/pii/S2095927324006819