In: Journal of Physics: Condensed Matter, 2011, vol. 23, no. 13, p. 135003
Using angle-resolved photoelectron spectroscopy we investigate the electronic valence band structure of the Si(331)-(12 × 1) surface reconstruction for which we recently proposed a structural model containing silicon pentamers as elementary structural building blocks. We find that this surface, reported to be metallic in a previous study, shows a clear band gap at the Fermi energy, indicating...
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In: Europhysics Letters, 2010, vol. 92, no. 4, p. 47003
We present angle-resolved photoemission experiments on 1T-TiSe₂ at temperatures ranging from 13 K to 288 K. The data evidence a dramatic renormalization of the conduction band below 100 K, whose origin can be related to the new potential responsible for the charge density wave phase at low temperature in this system. The renormalization translates into a substantial effective mass...
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In: Physical Review B, 2010, vol. 81, no. 15, p. 1551104
The charge-density-wave phase transition of 1T-TiSe₂ is studied by angle-resolved photoemission over a wide temperature range. An important chemical-potential shift which strongly evolves with temperature is evidenced. In the framework of the exciton condensate phase, the detailed temperature dependence of the associated order parameter is extracted. Having a mean-field-like behavior at low...
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In: Physical Review B: condensed matter and materials physics, 2009, vol. 80, no. 21, p. 214102
We recently proposed a structural model for the Si(331)-(12×1) surface reconstruction containing silicon pentamers and adatoms as elementary structural building blocks. Using first-principles density functional theory we here investigate the stability of a variety of adatom configurations and determine the lowest-energy configuration. We also present a detailed comparison of the energetics...
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In: Physica B: Condensed Matter, 2009, vol. 404, no. 19, p. 3172-3175
Recently, detailed calculations of the excitonic insulator phase model adapted to the case of 1T-TiSe2 have been presented. Through the spectral function theoretical photoemission intensity maps can be generated which are in very good agreement with experiment [H. Cercellier, et al., Phys. Rev. Lett. 99 (2007) 146403]. In this model, excitons condensate in a BCS-like manner and give rise to a...
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In: Chemistry - A European Journal, 2009///doi: 10.1002/chem.200900249
Sterically similar palladium dicarbene complexes have been synthesized that comprise permethylated dicarbene ligands which bind the metal center either in a normal coordination mode via C2 or abnormally via C4. Due to the strong structural analogy of the complexes, differences in reactivity patterns may be attributed to the distinct electronic impact of normal versus abnormal carbene bonding,...
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