论文标题
由于双层准扁平带引起的巨型异常大厅效应
Giant Anomalous Hall Effect due to Double-Degenerate Quasi Flat Bands
论文作者
论文摘要
我们提出了一种新型方法，以实现具有平坦带（FBS）的材料中的巨型AHE。 FB伴随着小电子带宽，因此，在韦尔点对内增加了动量分离（$ k $），从而增加了集成的浆果曲率。从具有单对Weyl节点的简单模型开始，我们通过减小带宽来证明$ K $和AHE的增加。它进一步扩展到具有特征性双重脱落FBS的逼真的Pyrochlore晶格模型，在那里我们发现了一个巨大的AHE，同时最大限度地利用了FBS的$ k $。我们确定基于第一原理计算，可以在Pyrochlore和尖晶石化合物中实现此类模型系统，从而验证我们的理论模型并为实验探索提供可行的平台。
We propose a novel approach to achieve giant AHE in materials with flat bands (FBs). FBs are accompanied by small electronic bandwidths, which consequently increases the momentum separation ($K$) within pair of Weyl points and thus the integrated Berry curvature. Starting from a simple model with a single pair of Weyl nodes, we demonstrated the increase of $K$ and AHE by decreasing bandwidth. It is further expanded to a realistic pyrochlore lattice model with characteristic double degenerated FBs, where we discovered a giant AHE while maximizing the $K$ with nearly vanishing band dispersion of FBs. We identify that such model system can be realized in both pyrochlore and spinel compounds based on first-principles calculations, validating our theoretical model and providing a feasible platform for experimental exploration.
