Yang Qun, Xiao Jiewen, Robredo Iñigo, Vergniory Maia G, Yan Binghai, Felser Claudia
Max Planck Institute for Chemical Physics of Solids, Dresden 01187, Germany.
Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel.
Proc Natl Acad Sci U S A. 2023 Nov 28;120(48):e2305541120. doi: 10.1073/pnas.2305541120. Epub 2023 Nov 20.
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.
手性与拓扑结构之间的相互作用孕育了许多奇异的电子特性。例如，拓扑手性半金属展现出多重手性费米子，这些费米子表现出非平凡的拓扑电荷和自旋纹理。它们是探索手性驱动的奇异物理现象的理想平台。在这项工作中，我们揭示了具有B20结构（例如RhSi和PdGa）的拓扑手性半金属的三维费米面存在类似单极子的轨道动量锁定纹理。这种轨道纹理在有电流流动时会产生大的轨道霍尔效应（OHE）和巨大的轨道磁电（OME）效应。不同的对映体表现出相同的OHE，在材料中通过自旋轨道耦合可将其转换为自旋霍尔效应。相比之下，OME效应是手性依赖的，并且比其自旋对应效应大得多。我们的工作揭示了轨道纹理在理解拓扑手性半金属中的OHE和OME效应方面的关键作用，并为轨道电子学、自旋电子学和对映体识别的应用铺平了道路。
