Recent progresses on artificial graphene quantum dots

Graphene quantum dots (GQDs) are an ideal platform for investigating the quantum confinement properties of Dirac fermions and exhibit significant potential for exploring novel physical phenomena absent in intrinsic graphene. Recently, the growing demand for relativistic confined systems with multiple tunable parameters has attracted much attention to the study of artificial GQDs. In this article, we review the recent experimental progress of artificial GQDs by using scanning tunneling microscopy (STM). Our review begins with an overview of the recent methods for fabricating GQDs. And then we introduce the novel findings proposed in different GQD systems, including atomic collapse states, molecular collapse states, correlation-induced spin-charge separation in monolayer GQDs, and the rotational symmetry broken states in Bernal-stacked bilayer GQDs. Moreover, the modulation of GQD properties through STM tip, external electric and magnetic fields are summarized. Lastly, we provide a perspective on future development in this field.