Speaker
Description
Chair: Xavier Gonze
Chiral phononics is an emerging field that utilizes the angular momentum of circularly polarized lattice vibrations to manipulate the properties of quantum materials. This has led to intriguing discoveries of emerging phenomena, including phononic analogues of spintronic and orbitronic effects, as well as the generation of atomistic tesla-scale magnetic fields that promise unprecedented control of magnetic order. In this talk, I will provide an introduction to the field and then present recent predictions of novel physical mechanisms from my group. Specifically, I will present a theory for the phonon angular momentum Hall effect that induces a transverse angular-momentum current and accumulation similar to the spin and orbital Hall effects for electrons. I will further show how chiral-phonon scattering leads to a rotational analogue of the Umklapp process in solids, demonstrating the conservation of crystal angular momentum.