Optical spectroscopy study of correlated electron physics in ABC-stacked trilayer graphene

Abstract

In recent years, people use 2D material as a building block to fabricate all kinds of multilayer stack devices, some of which host strongly correlated physics such as twist bilayer graphene and ABC-stack trilayer graphene. Mott insulator and superconductivity are found in these systems, which provide a cleaner and more controllable platform to study the strongly correlated physics than the traditional cuprate system. As a complementary method to trans- port measurement, which focuses on the low-frequency response, the optical spectrum is an important way to detect the frequency-dependent response and extract the underlying physics. In this project, we measured the optical spectrum on an ABC-stack trilayer graphene sample with the photocurrent method to understand the electron behavior in these delicate structures.