Photonic applications of ferroelectric group IV monochalcogenides (MXs) with in-plane anisotropy

Layered van der Waals materials have enabled novel electrical, optical and mechanical properties that are often distinctive from their 3-dimensional counterparts. 2D ferroic (ferromagnetic, ferroelectric) materials are bringing us new opportunities in controlling material response to external stimuli and enabling novel device applications such as memories. The MX (M= Sn, Ge; X=S, Se) material family have shown both 2D ferroelectricity and strong in-plane anisotropy, enabling a number of unique electrical, optical, thermal and mechanical properties. Here I would like to share some of our recent discoveries on this unique family of materials, including their nondegenerate valleytronic behaviors accessible with linear polarized light and photonic memories based on ferroelectric switching of MXs.