Conductive Atomic Force Microscopy Imaging of Rhombohedral Multilayer Graphene

Rhombohedral multilayer graphene (r-MLG) has attracted significant attention as a promising platform for exploring emergent quantum phenomena because of its exceedingly flat bands. Such intriguing low-energy electronic properties have recently been investigated using scanning tunneling microscopy and spectroscopy (STM/STS). However, STM measurements are often time-consuming, requiring ultraclean surfaces, and are typically performed under low-temperature conditions. Additionally, the low yield for rhombohedral stacking in multilayer films further compounds the difficulty for r-MLG STM studies. In contrast, conductive atomic force microscopy (c-AFM) provides a practical approach for screening and probing local electronic conductivity in multilayer graphene at room temperature. In this study, we employ c-AFM to reliably distinguish the rhombohedral (ABC) stacking order in multilayer graphene from the Bernal (ABA) configuration. Compared with STM, c-AFM enables faster mapping over larger areas, demands less stringent sample preparation, and operates under ambient conditions, making it well suited for efficiently identifying stacking domains in device-scale samples that can then be further investigated with STM.