Thomas Greber
April 15(Fri) - April 15(Fri), 2016
Title: The electronic structure of single layer h-BN and grapheneon transition
metals: From Nanomeshto quantum dots
Speaker: Thomas Greber(The University of Zürich)
Superhoneycomb-systems like a single layer of h-BN on Rh(111) [1] or grapheneon Ru(0001) [2] have a peculiar structure. Surface x-ray diffraction allows an accurate determination of the geometric arrangement of the atoms [3]. The apparent corrugation of thesesuper structure layers with a periodicity of about 3 nm impose lateral electrostatic fields, as observed with photoemission, and whichimpose new functionalities for molecular self-assembly [4]. The corrugation also imposes quantum dot behaviour[5] as it may be studied with scanning tunneling spectroscopy.
If intermetallic compounds like PtRhare used as substrates to grow h-BN layers, we may observe and quantify with x-ray photoelectron diffraction lateral segregation in the top lyersof the substrate [6].
[1] Corsoet al. Boron Nitride Nanomesh, Science, 303, 217 (2004).
[2] Bruggeret al. Comparison of electronic structure and template function of single-layer grapheneand a hexagonal boron nitride nanomeshon Ru(0001), Phys. Rev. B 79, 045407 (2009).
[3] Iannuzziet al. Moiré beatings in grapheneon Ru(0001), Phys. Rev. B 88, 125433 (2013).
[4] Dilet al. Surface Trapping of Atoms and Molecules with Dipole Rings,
Science 319, 1826 (2008).
[5] Zhang et al. GrapheneBased Quantum Dots, J. Phys.: Condens. Matter 22, 302001 (2010)
[6] Staniaet al. Self-assembly of nanoscalelateral segregation profiles, Phys. Rev. B (2016).