P4: Ab-initio description of chiral-phonon and spin coupling

• Applicant: Professorin Sangeeta Sharma, Ph.D.
• Subject Area: Theoretical Condensed Matter Physics
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 541503763

Phonon modes with degeneracy allow for a choice; one could excite linear or superposition of linear modes forming chiral phonons. Our primary aim constitutes a study of the effect of the light-induced pumping of chiral phonons on the electronic spin system in solids. For this we will use fully ab-initio method of coupling time-dependent density functional theory (TD-DFT) to Nuclear degrees of freedom. In this context we will first couple laser light to nuclear dynamics via the born effective charges. We will then study the effect of laser induced pumping of chiral phonons on the electronic spins. Finally we will consider double pump effects as applied to magnetic materials: THz/IR light to excite chiral phonons and optical light to excite the spin system.

• DFG Programme: Research Units
• Subproject of: FOR 5844: Chiral phonons for spintronics_ChiPS