2011/04/30 by Dinesh Subramaniam, D. Subramaniam, F. Libisch +20
Engineering · Materials Science · Physics and Astronomy · #Advancements in Battery Materials #Band gap #Condensed matter physics #Density functional theory #Density of states #Graphene #Graphene nanoribbons #Graphene research and applications #Lattice (music) #Local density of states #Materials science #Nanotechnology #Physics #Quantum and electron transport phenomena #Quantum dot #Quantum mechanics #Scanning tunneling microscope #Scanning tunneling spectroscopy #Wave function #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevlett.108.046801
published as Phys. Rev. Lett. 108, 046801 (2012) · 7 pages, 11 figures, DFT calculations directly showing the origin of soft confinment, correct identification of the state penetrating from Ir(111) into graphene
openalex publication_date 2012/01/23 · arxiv created 2012/02/06 · arxiv updated 2015/03/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Using low-temperature scanning tunneling spectroscopy, we map the local density of states of graphene quantum dots supported on Ir(111). Because of a band gap in the projected Ir band structure around the graphene K point, the electronic properties of the QDs are dominantly graphenelike. Indeed, we compare the results favorably with tight binding calculations on the honeycomb lattice based on parameters derived from density functional theory. We find that the interaction with the substrate near the edge of the island gradually opens a gap in the Dirac cone, which implies soft-wall confinement. Interestingly, this confinement results in highly symmetric wave functions. Further influences of the substrate are given by the known moiré potential and a 10% penetration of an Ir surface resonance into the graphene layer.