本征二维铁电金属PtBi2的电输运特性
The electrical transport of intrinsic two-dimensional ferroelectric metal PtBi2
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中文总结 AI 辅助
该研究探究本征二维铁电金属PtBi2的电输运特性，发现其高居里温度、可观电荷-自旋转换效率，设计出可实现非易失性阻态切换的铁电金属场效应晶体管，为相关器件设计提供见解。
中文摘要 AI 辅助
打破铁电体必然是绝缘体的传统刻板印象，二维（2D）铁电金属兼具看似不相容的可切换电极化与金属导电性，为发现新颖电输运现象及开发创新电子器件提供了沃土。本研究采用半经典玻尔兹曼方程与第一性原理计算，系统探究本征二维铁电金属\textit{PtBi2}对施加电场的线性与非线性输运响应。我们的\textit{ab initio}分子动力学模拟显示，其具有高达800 K的高居里温度；提出可通过面内电导率的简单测量明确区分其高温顺电相的晶体结构。对Edelstein效应与本征自旋霍尔效应的定量计算表明，该材料具备可观的电荷-自旋转换效率，凸显其在自旋电子学领域的潜力。我们还发现，在单轴应变的\textit{PtBi2}中会出现由贝利曲率偶极子诱导的非线性霍尔效应。此外，我们强调二维铁电金属在栅极控制输运应用中的独特优势，基于畴壁散射机制，概念性设计了一种新型铁电金属场效应晶体管（FEM-FET），该器件可在栅极电压下实现高阻与低阻态之间的非易失性切换。本研究不仅揭示了二维铁电金属中丰富的输运物理，还为下一代非易失性存储器与自旋电子器件的设计提供了宝贵见解。
英文摘要
Breaking the conventional stereotype that ferroelectrics are necessarily insulating, two-dimensional (2D) ferroelectric metals combine seemingly incompatible switchable electric polarization and metallic conductivity, providing a fertile ground for the discovery of novel electrical transport phenomena and the development of innovative electronic devices. Using the semiclassical Boltzmann equation and first-principles calculations, we systematically investigate the linear and nonlinear transport responses of the intrinsic 2D ferroelectric metal \ch{PtBi2} to an applied electric field. Our \textit{ab initio} molecular dynamics simulations reveal that it possesses a high Curie temperature reaching $800~\text{K}$. We propose that the crystal structure of its high-temperature paraelectric phase can be explicitly distinguished through simple measurements of the in-plane electrical conductivity. Quantitative calculations of the Edelstein effect and the intrinsic spin Hall effect demonstrate a sizable charge-to-spin conversion efficiency, highlighting its potential in spintronics. We also find that a Berry curvature dipole-induced nonlinear Hall effect emerges in uniaxially strained \ch{PtBi2}. Furthermore, we highlight the unique advantages of 2D ferroelectric metals in gate-controlled transport applications. Based on the domain wall scattering mechanism, we conceptually design a novel ferroelectric metal field-effect transistor (FEM-FET) capable of nonvolatile switching between high-resistance and low-resistance states under a gate voltage. Our work not only unveils the rich transport physics in 2D ferroelectric metals but also provides valuable insights into the design of next-generation nonvolatile memory and spintronic devices.
