Two-dimensional (2D) Rashba systems have been intensively studied in the last decade due to their unconventional physics, tunability capabilities, and potential for spin-charge interconversion when compared to conventional heavy metals. With the advent of a new generation of spin-based logic and memory devices, the search for Rashba systems with more robust and larger conversion efficiencies is expanding. Conventionally, demanding techniques such as angle- and spin-resolved photoemission spectroscopy are required to determine the Rashba parameter ${\alpha }_R$ that characterizes these systems. Here, we introduce a simple method that allows a quantitative extraction of ${\alpha }_R$, through the analysis of the bilinear response of angle-dependent magnetotransport experiments. This method is based on the modulation of the Rashba-split bands under a rotating in-plane magnetic field. We show that our method is able to correctly yield the value of ${\alpha }_R$ for a wide range of Fermi energies in the 2D electron gas at the ${\mathrm{LaAlO}}_3/{\mathrm{SrTiO}}_3$ interface. By applying a gate voltage, we observe a maximum ${\alpha }_R$ in the region of the band structure where interband effects maximize the Rashba effect, consistent with theoretical predictions.

中文翻译：

---

从二维电子气中的双线性磁阻响应确定Rashba参数

与常规重金属相比，二维（2D）Rashba系统具有非常规的物理特性，可调性以及自旋电荷互变的潜力，因此在过去十年中进行了深入研究。随着新一代基于自旋的逻辑和存储设备的出现，对具有更强大和更大转换效率的Rashba系统的搜索正在扩大。常规上，需要使用诸如角度分辨和自旋分辨光发射光谱等苛刻的技术来确定Rashba参数${\alpha }_{\mathrm{[R}}$这些系统的特征。在这里，我们介绍一种简单的方法，可以定量提取${\alpha }_{\mathrm{[R}}$，通过分析与角度相关的磁传输实验的双线性响应。该方法基于旋转平面内磁场下Rashba分裂带的调制。我们证明了我们的方法能够正确得出${\alpha }_{\mathrm{[R}}$ 在二维电子气中的费米能量范围很广 ${\mathrm{拉铝}}_3/{\mathrm{钛酸锶}}_3$接口。通过施加栅极电压，我们观察到最大${\alpha }_{\mathrm{[R}}$ 在频带结构的区域中，带间效应使拉什巴效应最大化，这与理论预测一致。