Advances in magneto-optical birefringence effect of 2D materials with extremely large aspect ratio

Abstract

Achieving giant magneto-optical birefringence is a long-standing goal in view of its intriguing physics and potential applications in transmitted light modulation. Due to the unique geometric features of two-dimensional materials with extremely large shape anisotropy, the resultant couplings among magnetic, electric, and optical properties enable giant magneto-optical birefringence effects, as represented by a record-breaking magneto-optical Cotton–Mouton coefficient in two-dimensional material systems. In this Perspective, we introduce the discovery of the giant magneto-optical birefringence effect in two-dimensional metal oxide dispersion in 2020, followed by analyses of the underlying mechanisms. We then discuss how the interplay of anisotropy and colloidal behavior affects the Cotton–Mouton effect. Finally, we proceed to potential applications and give our ideas about future developments in this emerging field.