发表机构
Indian Statistical Institute（印度统计研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文研究Aharonov-Bohm三角形量子网络中的可调平带，推导解析条件并证明电子比热可反映平带位置，提供识别平带的替代途径。
AI 中文摘要
由环状结构组成的量子网络为探索电子输运现象提供了丰富的平台，并在各种背景下得到了广泛研究。然而，其热响应仍相对未被探索，这促使我们在本工作中对其进行研究。我们考虑一个由有限数量的三角形板块组成的紧束缚（TB）量子网络，其中相邻板块通过单键连接，每个三角形回路被一个Aharonov-Bohm（AB）通量$\phi$穿过。非均匀位点配位、跳跃不对称性和量子干涉的相互作用产生了色散能级和完全平坦的能级。我们推导了一个涉及TB参数的解析条件，在该条件下，其中一个能量分支变得与电子动量无关。我们进一步表明，AB通量$\phi$提供了直接调节平带位置的手段。与该量子几何相关的能谱特征反映在热响应中，我们通过电子比热（ESH）对其进行了研究。特别是，我们证明了平带的位置在ESH中表现为一个独特的特征，建立了平带形成与系统热响应之间的直接联系。因此，ESH提供了一种识别平带存在的替代途径，与解析条件和相应的能量色散一致。此外，AB通量允许通过调节平带位置来选择性地调控ESH。所提出的方法提供了一种简单的补充手段来识别与动量无关的能级，并可扩展到其他支持平带的简单和复杂量子网络。
英文摘要
Quantum networks composed of loop-like structures provide a rich platform for exploring electronic transport phenomena and have been widely studied in various contexts. However, their thermal response remains relatively unexplored, motivating us to investigate it in the present work. We consider a tight-binding (TB) quantum network composed of a finite number of triangular plaquettes, where neighboring plaquettes are connected through single bonds and each triangular loop is threaded by an Aharonov-Bohm (AB) flux $ϕ$. The interplay of nonuniform site coordination, hopping asymmetry, and quantum interference gives rise to both dispersive and completely flat energy levels. We derive an analytical condition involving the TB parameters under which one of the energy branches becomes independent of the electronic momentum. We further show that the AB flux $ϕ$ provides a direct means of tuning the position of the flat band. The characteristic features of the energy spectrum associated with this quantum geometry are reflected in the thermal response, which we investigate through the electronic specific heat (ESH). In particular, we demonstrate that the position of the flat band manifests itself as a distinct feature in the ESH, establishing a direct connection between the flat-band formation and the thermal response of the system. Thus, the ESH provides an alternative route for identifying the presence of a flat band, consistent with the analytical condition and the corresponding energy dispersion. Moreover, the AB flux allows the ESH to be selectively regulated through the tuning of the flat-band position. The proposed approach provides a simple complementary means of identifying momentum-independent energy levels and may be extended to other simple and complex quantum networks supporting flat bands.
Comments12 pages, 12 figures. Comments are welcome
