在这项研究中，研究人员揭示了具有B20结构的拓扑手性半金属（例如RhSi和PdGa）的三维费米表面上的类单极轨道动量锁定织构的特性。当有电流流动时，这种轨道结构可以产生显著的轨道霍尔效应(OHE)和巨大的轨道磁电效应(OME)。值得注意的是，不同的对映体表现出相同的OHE，这种效应可以通过材料中的自旋-轨道耦合转化为自旋霍尔效应。然而，与此相反，OME效应则表现出对手性的依赖，并且其效应比自旋效应大得多。这项研究工作深入揭示了轨道织构在理解拓扑手性半金属中OHE和OME效应的核心作用，并为轨道电子学、自旋电子学以及对映体识别的未来应用铺平了道路。
据悉，手性与拓扑结构之间的相互作用导致了许多奇特的电子性质的出现。举例来说，拓扑手性半金属表现出了多重手性费米子，表现出非平凡的拓扑电荷以及自旋织构。这些特性使得拓扑手性半金属成为了探究手性驱动的奇特物理现象的理想研究对象。
附：英文原文
Title: Monopole-like orbital-momentum locking and the induced orbital transport in topological chiral semimetals
Author: Yang, Qun, Xiao, Jiewen, Robredo, Iigo, Vergniory, Maia G., Yan, Binghai, Felser, Claudia
Issue&Volume: 2023-11-20
Abstract: The interplay between chirality and topology nurtures many exotic electronic properties. For instance, topological chiral semimetals display multifold chiral fermions that manifest nontrivial topological charge and spin texture. They are an ideal playground for exploring chirality-driven exotic physical phenomena. In this work, we reveal a monopole-like orbital-momentum locking texture on the three-dimensional Fermi surfaces of topological chiral semimetals with B20 structures (e.g., RhSi and PdGa). This orbital texture enables a large orbital Hall effect (OHE) and a giant orbital magnetoelectric (OME) effect in the presence of current flow. Different enantiomers exhibit the same OHE which can be converted to the spin Hall effect by spin-orbit coupling in materials. In contrast, the OME effect is chirality-dependent and much larger than its spin counterpart. Our work reveals the crucial role of orbital texture for understanding OHE and OME effects in topological chiral semimetals and paves the path for applications in orbitronics, spintronics, and enantiomer recognition.
DOI: 10.1073/pnas.2305541120
Source: https://www.pnas.org/doi/abs/10.1073/pnas.2305541120