Dr. Sang Mo Yang, Sogang University, South Korea

Title: Ferroelectricity at the Nanoscale: Emerging Materials and Local Probes

Abstract: Ferroelectricity on the nanoscale has been the subject of considerable interest in condensed matter physics for over half a century. Beyond its fundamental importance, ferroelectricity provides essential functionality for advanced electronic devices, including nonvolatile memories, field-effect transistors and tunnel junctions. 

However, conventional perovskite-based ferroelectric oxides (e.g., Pb(Zr,Ti)O3) face significant challenges in achieving device performance that can compete with current dynamic random-access memories and flash memories. Over the past decade, novel ferroelectricity has been discovered in new material systems, including fluorite-structured HfO2-based thin films, two-dimensional (2D) van der Waals (vdW) materials and 2D perovskite halides. These discoveries have brought about a renaissance in the ferroelectric research community. 

In this colloquium, I will present our group’s recent efforts to investigate and understand ferroelectricity across these emerging material platforms [1] using various scanning probe microscopy techniques.
[1] T. H. Jung et al., “Spatially Resolved Observation of Ferroelectric-to-Paraelectric Phase Transition in a Two-Dimensional Halide Perovskite,” Advanced Materials 37, 2506270 (2025)