We find that in BaTiO3 the phonon angular momentum is dominantly pointing in directions perpendicular to the electrical polarization. Therefore, external electric field in ferroelectric BaTiO3 does not control only the direction of electrical polarization, but also the direction of phonon angular momentum. This finding opens up the possibility for electric-field control of physical phenomena that rely on phonon angular momentum. We construct an intuitive model, based on our first-principles calculations, that captures the origin of the relationship between phonon angular momentum and electric polarization.
@article{arxiv.2103.06316,
title = {Electric field control of phonon angular momentum in perovskite BaTiO$_3$},
author = {Kevin Moseni and Richard B Wilson and Sinisa Coh},
journal= {arXiv preprint arXiv:2103.06316},
year = {2022}
}