2026/04/28 by Tomomi Tateishi, Akihito Kato, Alexander S. Ovchinnikov +1 · 1 voice · 1 citation
Physics and Astronomy · #cond-mat.other
paper · pdf · doi:10.7566/jpsj.95.063705
arxiv published 2026/04/28 · arxiv updated 2026/04/29
We present a microscopic theory of chirality-induced orbital selectivity (CIOS) in helical crystals, in which truly chiral phonons selectively transfer angular momentum to electronic orbital degrees of freedom. For a threefold helical crystal with line-group symmetry L31, we show that phonon-induced local rotations generate a rotational electron-phonon interaction proportional to L±, which drives the orbital transfer mℓ→ mℓ-ms in accordance with crystal angular momentum (CAM) conservation, where ms=± 1 denotes the eigenvalue of the phonon rotational mode. Evaluating ⟨Lz⟩ to leading order in perturbation theory, we find that the orbital response is suppressed near the Γ point and the BZ boundary, and enhanced at intermediate wave vectors -- a feature intimately tied to the degeneracy structure of the phonon bands.