三维费米面与单晶锑薄片的厚度调控磁输运
Three-Dimensional Fermiology and Thickness-Tuned Magnetotransport in Single-Crystalline Antimony Flakes
- South China University of Technology（华南理工大学）
- Donghua University（东华大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本文通过CVD生长的单晶锑薄片，结合磁输运和量子振荡测量，发现厚度增加通过提升载流子迁移率而非改变费米面结构，使极端磁电阻增强近30倍，揭示了维度依赖散射的调控机制。
AI中文摘要：
补偿半金属的极端磁电阻由费米面几何和载流子弛豫共同决定，但在有限尺寸结构中这些贡献难以区分。本文结合纵向和霍尔磁输运测量以及随温度和角度变化的Shubnikov--de Haas振荡，研究了通过化学气相沉积（CVD）生长的单晶Sb薄片，厚度范围为110至783 nm。随着厚度增加，2 K和14 T下的非饱和磁电阻（MR）上升近30倍，达到$7.13\times10^{5}\\%$，而主频率$F_{\alpha}$保持在约99 T，无系统性偏移。对$\rho_{xx}(B)$和$\rho_{xy}(B)$的联合三通道分析表明，这种演变是由近乎补偿的电子-空穴对的迁移率增加驱动的，而非主费米口袋的重构。角度依赖测量证实了闭合三维$\alpha$口袋的存在，且可重现的高频段（335-377 T）与体相Sb中$L$点口袋的电子$\beta$轨道一致。综合输运和量子振荡结果表明，厚度通过维度依赖的散射调控极端磁电阻，同时保持类体相的费米面拓扑。
英文摘要：
The extreme magnetoresistance of compensated semimetals is governed by both the Fermi-surface geometry and carrier relaxation, but these contributions are difficult to disentangle in finite-size structures. Here, we combine longitudinal and Hall magnetotransport measurements with temperature- and angle-dependent Shubnikov--de Haas oscillations in single-crystalline Sb flakes grown by chemical vapor deposition (CVD), with thicknesses ranging from 110 to 783 nm. As thickness increases, the non-saturating MR at 2 K and 14 T rises nearly 30-fold, reaching $7.13\times10^{5}\%$, while the primary frequency $F_α$ remains approximately 99 T without any systematic shift. A joint three-channel analysis of $ρ_{xx}(B)$ and $ρ_{xy}(B)$ reveals that this evolution is driven by an increase in the mobility of a nearly compensated electron--hole pair, rather than by a reconstruction of the primary pockets. Angle-dependent measurements confirm the existence of a closed three-dimensional $α$ pocket, and a reproducible high-frequency sector (335-377 T) is consistent with the electron $β$ orbit of the $L$-point pockets in bulk Sb. Together, the transport and quantum-oscillation results show that thickness tunes extreme MR through dimension-dependent scattering while preserving bulk-like fermiology.
