Electric-Dipole Quasiparticles for THz and Quantum Technologies

Collective excitations in quantum materials offer powerful pathways to probe and control emergent phases. Ferroelectric materials are predicted to host ferrons, i.e. the electric-dipole analogs of magnons, but they have remained experimentally elusive. I will present our discovery of coherent ferrons in the van der Waals ferroelectric NbOI₂. Using ultrafast optical excitation, we launch polarization waves that propagate uniaxially at hypersonic velocities, emit narrow-band terahertz radiation, and modulate the ferroelectric order parameter. These results establish a new platform narrow-band THz sources, energy-efficient information processing, and coherent electric control in future quantum technologies.