论文标题
二维稀有碘化物的计算发现：有前途的弗罗拉利材料用于谷LeTronics
Computational Discovery of Two-Dimensional Rare-Earth Iodides: Promising Ferrovalley Materials for Valleytronics
论文作者
论文摘要
具有内在山谷极化的二维Ferrovalley材料对于基于山谷的非挥发性随机访问记忆和山谷过滤器非常有前途。使用动力学有限的最小化（KLM），一种不受约束的晶体结构预测算法以及基于第一原理计算的原型采样，我们发现了17种新的Ferrovalley材料（Rare-Earth Iodides ri $ _2 $，其中r是SC，y是SC，y是sc，y，是的，是的，是的，是的，是的，是的，是y la-lu-lu-lu-lu-lu-lu-lu和iodine）。稀有碘化物是分层的，并证明了2H，1T或1T $ _D $相位，作为地面的散装，类似于过渡金属二甲硅烷基（TMDC）。单层的计算出的去角质能与石墨烯和TMDC相当，表明可能的实验合成。 2H阶段的单层表现出二维铁磁磁性，这是由于$ d $和$ f $ orbitals中的未配对电子而导致的。在整个稀土系列中，$ d $ bands在$ k $和$ \ bar {k} $点上的布里群岛区域附近的费米级别的$ \ bar {k} $点。由于强烈的磁交换相互作用和自旋轨道耦合，观察到没有外部刺激的15-143 MEV范围内的大型内部山谷极化，可以通过施加双轴应变来调整和增强。可以选择性地探测和操纵这些山谷，以进行信息存储和处理，从而超出了传统的电子设备和旋转型的卓越性能。我们进一步表明，Ri $ _2 $单层的2H铁磁相具有非零的浆果曲率，并以相当多的异常电导率展示了Valley Hall效应。我们的工作将促进预测的Ferrovalley材料及其在Valleytronics及其他地区的应用。
Two-dimensional Ferrovalley materials with intrinsic valley polarization are rare but highly promising for valley-based nonvolatile random access memory and valley filter. Using Kinetically Limited Minimization (KLM), an unconstrained crystal structure prediction algorithm, and prototype sampling based on first-principles calculations, we have discovered 17 new Ferrovalley materials (rare-earth iodides RI$_2$, where R is a rare-earth element belonging to Sc, Y, or La-Lu, and I is Iodine). The rare-earth iodides are layered and demonstrate 2H, 1T, or 1T$_d$ phase as the ground-state in bulk, analogous to transition metal dichalcogenides (TMDCs). The calculated exfoliation energy of monolayers is comparable to that of graphene and TMDCs, suggesting possible experimental synthesis. The monolayers in the 2H phase exhibit two-dimensional ferromagnetism due to unpaired electrons in $d$ and $f$ orbitals. Throughout the rare-earth series, $d$ bands show valley polarization at $K$ and $\bar{K}$ points in the Brillouin zone near the Fermi level. Due to strong magnetic exchange interaction and spin-orbit coupling, large intrinsic valley polarization in the range of 15-143 meV without external stimuli is observed, which can be tuned and enhanced by applying a biaxial strain. These valleys can selectively be probed and manipulated for information storage and processing, potentially offering superior performance beyond conventional electronics and spintronics. We further show that the 2H ferromagnetic phase of RI$_2$ monolayers possesses non-zero Berry curvature and exhibits the valley Hall effect with considerable anomalous Hall conductivity. Our work will incite exploratory synthesis of the predicted Ferrovalley materials and their application in valleytronics and beyond.
