In JoVE (1)
Other Publications (1)
Articles by Youngkyou Kim in JoVE
Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities Han Sae Jung1,2, Hsin-Zon Tsai1, Dillon Wong1, Chad Germany1, Salman Kahn1, Youngkyou Kim1,3, Andrew S. Aikawa1, Dhruv K. Desai1, Griffin F. Rodgers1, Aaron J. Bradley1, Jairo Velasco Jr.1, Kenji Watanabe4, Takashi Taniguchi4, Feng Wang1,5,6, Alex Zettl1,5,6, Michael F. Crommie1,5,6 1Department of Physics, University of California at Berkeley, 2Department of Chemistry, University of California at Berkeley, 3Department of Chemical and Biomolecular Engineering, University of California at Berkeley, 4National Institute for Materials Science (Japan), 5Materials Sciences Division, Lawrence Berkeley National Laboratory, 6Kavli Energy NanoSciences Institute, University of California at Berkeley and Lawrence Berkeley National Laboratory This paper details the fabrication process of a gate-tunable graphene device, decorated with Coulomb impurities for scanning tunneling microscopy studies. Mapping the spatially dependent electronic structure of graphene in the presence of charged impurities unveils the unique behavior of its relativistic charge carriers in response to a local Coulomb potential.
Other articles by Youngkyou Kim on PubMed
Imaging and Tuning Molecular Levels at the Surface of a Gated Graphene Device ACS Nano. Jun, 2014 | Pubmed ID: 24746016 Gate-controlled tuning of the charge carrier density in graphene devices provides new opportunities to control the behavior of molecular adsorbates. We have used scanning tunneling microscopy (STM) and spectroscopy (STS) to show how the vibronic electronic levels of 1,3,5-tris(2,2-dicyanovinyl)benzene molecules adsorbed onto a graphene/BN/SiO2 device can be tuned via application of a backgate voltage. The molecules are observed to electronically decouple from the graphene layer, giving rise to well-resolved vibronic states in dI/dV spectroscopy at the single-molecule level. Density functional theory (DFT) and many-body spectral function calculations show that these states arise from molecular orbitals coupled strongly to carbon-hydrogen rocking modes. Application of a back-gate voltage allows switching between different electronic states of the molecules for fixed sample bias.