Electromagnetic Radiation Interactions with Perovskite Nickelates

We will discuss frequency-tunable electrical response in perovskite nickelate thin films exposed to electromagnetic radiation. By systematically comparing the effects of radio frequency (RF) and ultraviolet (UV) stimuli, we reveal that nickelates exhibit rapid short-term reversible resistance modulation under RF excitation and long-term, glass-like relaxation under UV exposure. Optical frequency emerges as a powerful control parameter for inducing multi-timescale memory responses, enabling access to glassy dynamics far beyond the limits traditionally constrained by proximity to thermal phase transitions. Remarkably, optical stimulus trains can result in induction of non-associative learning, showing that nickelates can mimic adaptive behaviour noted in biological systems. We will discuss the mathematical modelling of these behaviours using dynamical systems approaches. Together, the results open new frontiers to study strong correlations in nickelates utilizing optical fields.