Electronic orbital angular momentum dynamics mediated by electron-chiral phonon interactions in helical chains
Phys. Rev. B 114, 094413 – Published 7 August, 2026
DOI: https://doi.org/10.1103/c42k-r3mm
Abstract
The generation of electron orbital angular momentum (OAM) is the key for the field of orbitronics. Recently, the observation of orbital Seebeck effect [Y. Nabei et al., Nat. Phys. 22, 245 (2026)] shows that OAM can be generated by chiral phonons in materials with broken inversion symmetry. However, how electron-chiral phonon (ECP) interaction affects electric-field-induced electronic OAM dynamics remains unclear. In this work, we investigate ECP-mediated electronic OAM dynamics in a one-dimensional helical chain described by a Su-Schrieffer-Heeger model. The microscopic electronic OAM is defined from the operator , while the main dynamical calculations employ a phonon OAM-based approximation whose validity is benchmarked against the microscopic electronic OAM. We show that, under the local-equilibrium-center definition and in the electron-phonon coupling regime used in the main calculations, this approximation captures the main dynamical features of electronic OAM. The slowly varying axial component is associated with an orbital-Edelstein-like electronic OAM polarization, whereas the transverse components mainly exhibit coherent precessional dynamics. We further find that chirality controls the sign and dynamical pattern of electronic OAM, while spin-orbit coupling is not the dominant channel for the ECP-driven electronic OAM dynamics in the present model.
