Sliding ferroelectrics (sFEs) have emerged as a promising platform for two-dimensional fatigue-free nonvolatile electronics, but their high switching barriers remain a major challenge for achieving low coercive fields. Superlubric sliding ferroelectrics (SL-sFEs), recently proposed by inserting an incommensurate spacer layer to reduce interlayer friction, offer a possible route to overcome this limitation; however, the mechanism by which polarization persists across widely separated and effectively decoupled outer layers remains unclear. In this talk, I will present our theoretical and first-principles study showing that the physical mechanism of SL-sFEs is fundamentally different from that of conventional sFEs. Rather than being driven by interlayer sliding alone, the polarization in SL-sFEs arises from the coupled interplay between sliding and the out-of-plane buckling of the spacer layer. This coupling gives rise to a unique hybrid electronic–ionic origin of polarization, associated with asymmetric orbital hybridization between the spacer and outer layers and controlled by both sliding and buckling. Furthermore, the interaction between these two order parameters leads to rich ferroelectric switching behaviors, including mixed first- and second-order transitions and multi-step hysteresis loops. These results establish SL-sFEs as a distinct class of two-dimensional ferroelectrics governed by the interplay of sliding, buckling, and electronic–ionic degrees of freedom, providing new insights for the design of low-power two-dimensional ferroelectric devices.

Jing Huang is a Research Fellow working with Prof. Daniel Bennett at Nanyang Technological University since 2025. He obtained his Ph.D. from Beijing Computational Science Research Center in 2025. His current research focuses on first-principles calculations of two-dimensional ferroelectrics and point defects in semiconductors.