seed projects

Turan Birol, Renee Frontiera: Quantifying Angular Momentum in Chiral Phonons

(left) Chiral crystal structure of FeSi. (right) The fully symmetric zone center phonon modes can be understood as a rotational vibration around the 3-fold symmetry axis of the cubic cell (shown in black).

This project aims to elucidate the dynamics and patterns of phonons in chiral FeSi. FeSi is a well studied insulator that brings together the rare combination of chirality with a cubic crystal structure, but its lattice response and dynamics are understudied. Birol's first principles calculations will predict the behavior of the zone-center lattice vibrations of FeSi, and the degree to which they carry angular momentum that can be measured using Frontiera's Raman spectroscopy using circularly polarized light. This seed will pave the way for future studies of not only FeSi, but also heat and electronic transport in nonmagnetic chiral materials.

Funded by the National Science Foundation through the University of Minnesota MRSEC under Award Number DMR-2011401