Spatially Mapping Dirac Fermions in a Graphene Quantum Dot

Quantum confinement in graphene is important for tuning and exploiting graphene's electronic, spin, and optical properties. Here we present a novel technique for creating gate-tunable graphene quantum dots that are fully exposed and compatible with surface characterization tools. Using scanning tunneling microscopy (STM), we are able to spatially visualize and characterize the electronic structure of these gate-tunable graphene quantum dots. The quantum interference patterns observed in this way can be compared to the predictions of the Dirac equation, thus providing new insight into the behavior of confined ultra-relativistic Dirac fermions.