AI 中文总结
该研究证明几何随机性可独立产生量子混沌与扩散输运，通过分析随机局域树状分层图上的无相互作用量子粒子，揭示了层大小、有效维度对混沌及输运行为的调控作用。
AI 中文摘要
量子混沌与扩散输运的物理通常在存在微观无序或多体相互作用的场景中研究。本文中，我们证明这些现象可纯粹由几何随机性产生。通过研究均匀耦合的随机局域树状分层图上的无相互作用量子粒子，我们发现几何随机性与有效图维度决定了混沌动力学的存在与否。这类图可视为规则方格或梯的结构无序推广，等价于多组分一维链，组分间存在随机连接。我们发现，广延层大小会产生鲁棒的量子混沌、能级排斥与扩散输运；相反，在准一维极限下，存在广延数目的局域态与离域态共存，这导致能级排斥被抑制，离域态主导弹道输运。这些结果确立了几何随机性作为产生与调控量子混沌的基本且独立机制。
英文摘要
The physics of quantum chaos and diffusive transport is typically studied in settings with microscopic disorder or many-body interactions. In this Letter, we demonstrate that these phenomena can arise purely from geometric randomness. By studying non-interacting quantum particles on random locally tree-like layered graphs with uniform couplings, we show that the geometric randomness and effective graph dimensionality dictates the presence of chaotic dynamics or lack thereof. These graphs can be considered as structurally disordered generalisations of regular square lattices or ladders, or equivalently as multi-component one-dimensional chains with random links between the components. We find that an extensive layer size yields robust quantum chaos, level repulsion, and diffusive transport. Conversely, in the quasi-one-dimensional limit, we find the coexistence of extensive number of localised and delocalised states -- this leads to suppressed level repulsion accompanied by the latter driving ballistic transport. These results establish geometric randomness as a fundamental and independent mechanism for generating and tuning quantum chaos.
Comments8 pages, 6 figures
