Electron-phonon coupling in magnetic materials, ultrafast spin-lattice dynamics, Raman optical activity and chiral phonons, quantum geometry and Berry phase physics, multiferroics, and finite-temperature first-principles methods.
A first-principles framework combining DFPT, atomistic spin-lattice dynamics, and maximally localized Wannier functions to investigate phonon-driven phenomena in magnetic materials, including finite-temperature exchange, ultrafast demagnetization, and giant Raman optical activity.
Ab-initio Hubbard models and superexchange theory show coexisting orbital, canted antiferromagnetic, and ferroelectric orders in CsO2, with a spin-flop transition that induces ferroelectricity through antisymmetric exchange striction.
Time-resolved SHG measurements and first-principles spin-lattice dynamics identify exchange striction as the key material parameter controlling ultrafast demagnetization in Cr2O3.
First-principles calculations connect giant Raman optical activity in Ni3TeO6 to phonon-driven modification of interband Berry curvature in solids.
A two-supercell ab-initio method for temperature-dependent exchange interactions reveals non-universal behavior, including an anomalous ~10% enhancement at 300 K in Cr2O3.
Poster presentation by Ravi Kaushik.