Harnessing Noise for Sub-Coercive Polarization Switching in Ferroelectric PZT capcaitors

Noise is traditionally regarded as a detrimental factor in physical and electronic systems—something to be filtered, suppressed, or eliminated. However, the counterintuitive phenomenon of stochastic resonance (SR) challenges this long-held perspective by demonstrating that under certain conditions, an optimal amount of noise can enhance the response of a nonlinear system to a weak, otherwise undetectable signal. Originating from studies on climate cycles and later extended to a wide variety of physical and biological systems, SR represents a unique intersection of noise, nonlinearity, and coherence. In a bistable system, SR manifests as an enhancement of signal-induced transitions between two potential wells when the noise-induced hopping rate becomes commensurate with the frequency of the external drive. In this work, we experimentally realize stochastic resonance in a thin-film ferroelectric lead zirconate titanate (PZT) capacitor, and demonstrate synchronous polarization switching at voltages far below the coercive threshold of the material. For teh first time we experimentally measure kramers time in a ferroelectric system. Our results reveal that the introduction of an optimal level of electrical noise enables sub-coercive domain switching, in close agreement with the theoretical SR condition. By exploiting this noise-assisted switching mechanism, we show how ferroelectric devices can detect weak sub-threshold signals or perform low-energy information transfer, opening new possibilities for noise-enabled computation, communication, and sensory systems.