  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.
