标题： 通过高场磁电输运测量揭示电荷密度波和拓扑半金属TaTe4的电子结构 显示英文标题

标题： Unveiling the electronic structure of the charge density wave and topological semimetal TaTe4 through high-field magnetotransport measurements

摘要： 理解拓扑结构与关联电子态之间的相互作用是量子材料研究的核心。TaTe$_4$是一种预测可承载拓扑相的电荷密度波 (CDW) 化合物，为探索这种相互作用提供了平台。在此，我们通过高场磁输运测量和密度泛函理论 (DFT) 计算对 TaTe$_4$的费米面 (FS) 进行了全面研究。使用三种不同的场-电流配置，我们解析了在 CDW 相中预测的五个 FS 袋中的四个，没有发现残留的非 CDW 特征——这与最近的 ARPES 研究形成对比。值得注意的是，我们发现了一个之前未观察到的准圆柱形空穴袋，并且在磁阻中观察到一个由于重构费米面片之间的磁破裂导致的高频量子振荡贡献，由此我们估计 CDW 带隙为$\sim$0.29 eV。此外，当电流沿$a-$轴流动时，所有磁场方向下都观察到了稳健的线性磁阻 (MR)，在接近$c-$轴处出现了一个独特的高磁场线性 MR 区域，这与费米面热点和磁破裂一致。我们的结果确立了 TaTe$_4$作为一个典范体系，其中 CDW 驱动的费米面重构主导了体电子结构，从而为探测关联电子态与拓扑能带特征交汇处可能出现的新物理现象提供了新途径。 显示英文摘要

摘要： Understanding the interplay between topology and correlated electron states is central to the study of quantum materials. TaTe$_4$, a charge density wave (CDW) compound predicted to host topological phases, offers a platform to explore this interplay. Here, we report a comprehensive study of the Fermi surface (FS) of TaTe$_4$ via high-field magnetotransport measurements and density functional theory (DFT) calculations. Using three distinct field-current configurations, we resolve four out of five FS pockets predicted in the CDW phase, with no evidence of residual non-CDW features - in contrast to recent ARPES studies. Remarkably, we identify a previously unobserved quasi-cylindrical hole pocket and a high-frequency quantum oscillation contribution to the magnetoresistance attributable to magnetic breakdown between reconstructed FS sheets, from which we estimate a CDW gap of $\sim$0.29 eV. Additionally, we observe a robust linear magnetoresistance (MR) for all field orientations when current flows along the $a-$axis, with a distinct high-field linear MR regime emerging near the $c-$axis, consistent with FS hot spots and magnetic breakdown. Our results establish TaTe$_4$ as a paradigmatic system where CDW-driven FS reconstruction governs the bulk electronic structure, enabling new routes to probe the novel physics that can arise in the intersection between correlated electronic states and topological band features.