论文标题
观察pdsb $ _2 $中的六倍退化费米子
Observation of sixfold degenerate fermions in PdSb$_2$
论文作者
论文摘要
在拓扑量子材料中，已经对三种类型的费米子进行了广泛的研究：Dirac，Weyl和Majorana Fermions。除了高能量物理学的基本费用外，居住在三，六或八倍的堕胎带交叉处的冷凝物质系统中还允许外来的费物。在这里，我们使用角度分辨的光发射光谱直接在PDSB $ _2 $中直接可视化三分化的频段。我们能够实现的超高能量分辨率允许在R点处确认所有六倍的退化带，并与第一原理计算相当一致。此外，我们发现这种六倍的退化交叉具有正常的二次分散体，如理论所预测的那样。最后，我们将六倍的堕落费米子与先前确认的费米子进行了比较，以证明这项工作的重要性：我们的研究表明，超出了高能量物理学的限制。
Three types of fermions have been extensively studied in topological quantum materials: Dirac, Weyl, and Majorana fermions. Beyond the fundamental fermions in high energy physics, exotic fermions are allowed in condensed matter systems residing in three-, six- or eightfold degenerate band crossings. Here, we use angle-resolved photoemission spectroscopy to directly visualize three-doubly-degenerate bands in PdSb$_2$. The ultrahigh energy resolution we are able to achieve allows for the confirmation of all the sixfold degenerate bands at the R point, in remarkable consistency with first-principles calculations. Moreover, we find that this sixfold degenerate crossing has quadratic dispersion as predicted by theory. Finally, we compare sixfold degenerate fermions with previously confirmed fermions to demonstrate the importance of this work: our study indicates a topological fermion beyond the constraints of high energy physics.
