Würzburg ToCoTronics Colloquium

Chirality is a property of an object not identical to its mirror image. Electrons in chiral crystals and molecules are expected to acquire a chiral orbital motion, potentially allowing for sizable orbital Hall and orbital magnetoelectric effects. I will present experimental evidence for chirality-driven electron orbital motion in a chiral crystal, CoSi, based on soft X-ray photoelectron spectroscopy with circularly polarized X-rays [1]. Observation of strongly handedness-dependent circular dichroism shows the formation of an orbital-angular-momentum texture with chiral orbital-momentum locking. In the context of these results, I will conclude with a brief outlook on future prospects of dichroic and spin-resolving photoemission as a probe of symmetry-broken states through combining real and reciprocal space imaging. 

[1] Stefanie S. Brinkman et al., arXiv:2404.02952 (to be published in Phys. Rev. Lett.)