Sub-nanosecond polarization switching with anomalous kinetics in vdW ferroelectric WTe₂

Recently discovered "sliding ferroelectrics" exhibit distinct polarization origin and switching mechanism compared to conventional ferroelectric materials. However, a clear understanding of the polarization switching kinetics remains lacking. Here, we demonstrate sub-nanosecond (0.6 ns) polarization switching in the sliding ferroelectrics WTe₂, which is the fastest switching observed so far in van der Waals ferroelectrics. Furthermore, the conventional nucleation-limited-switching model can still be applied to describe the switching process. However, contrary to conventional ferroelectric materials, the activation field associated with polarization reversal increases with temperature. Theoretical analysis suggests that this behavior is linked to the charge transfer nature of polarization in WTe₂ and the unique sliding mechanism for polarization switching. Additionally, the device demonstrates remarkable endurance, with no fatigue observed after 10¹⁰ switching cycles. This study provides valuable insights into the polarization reversal process in sliding ferroelectrics and paves the way for future advances in nanoelectronic and spintronic applications.