Alon Ron

Zuckerman Faculty Scholar Alon Ron published “Non adiabatic dynamics of the ferroelectric soft mode,” in the current arXiv:2602). In his Femto Quantum Materials Lab at Tel Aviv University’s School of Physics and Astronomy, Dr. Ron and his team study how materials respond on ultrafast timescales and investigate ferroelectrics — materials that can switch built-in electric polarization (like a tiny, reversible battery), used in sensors, actuators, and memory concepts. Using ultrafast laser measurements, they tracked how polarization changes and how atoms move in the crystal, or “soft-mode” vibration, in the material SnTe. They found that these two responses can temporarily fall out of sync: the polarization changes in a strongly nonlinear way even while the atomic vibration remains close to harmonic. Understanding this split helps scientists build more realistic models of switching and, over time, could guide the design of faster and more efficient ferroelectric-based devices.

Abstract:
Most microscopic descriptions of structural dynamics assume the Born-Oppenheimer separation, where electrons adjust adiabatically to ionic motion. When this separation breaks down, electronic and lattice degrees of freedom can evolve on different timescales, giving rise to new physical phenomena beyond the adiabatic limit. Here we use time-resolved, phase-sensitive second-harmonic generation and pump-probe reflectivity to reshape the ferroelectric free-energy landscape of SnTe while separately tracking polar order and coherent lattice motion.