Theoretical Design of 2D Ferroelectric and Multiferroic Materials

In this talk, we will first present a discovery of a 2D ferroelectric materials family, rooted in III2-VI3 van der Waals materials and distinctly characterized by exhibiting versatile ferroelectricity with both in-plane and out-of-plane electric polarization. The device potentials of these new 2D ferroelectric materials will be demonstrated using the van der Waals heterostructures. Based on these discovered 2D ferroelectric materials, we further propose a design of 2D multiferroic materials via doping a small amount of magnetic ions into the 2D ferroelectric material. This design provides a novel multiferroic system based on van der Waals 2D materials, and these 2D multiferroic materials are expected to have strong coupling between the ferroelectric polarization and the magnetic order.