Abstract
We have studied temperature dependence of the two proximal bands, S1 and S2, from the one-dimensional (1D) Au/Si(557) system using angle-resolved photoemission spectroscopy with synchrotron photons. The intriguing feature of these bands reported earlier, metallic S1 and insulating S2 at room temperature [J. R. Ahn, H. W. Yeom, H. S. Yoon, and I. W. Lyo, Phys. Rev. Lett. 91, 196403 (2003)], has neither been reproduced nor understood properly yet. Our band images, however, unambiguously reveal that both bands behave nearly identically with temperature and remain metallic for as seen by the well-defined Fermi-Dirac edges. We thus exclude the presence of a Peierls-type metal-insulator transition claimed earlier and discuss possible causes for the difference. The metallic nature of these bands is further illustrated by the presence of a satellite peak in the core level reflecting the 1D plasmon excitation.
- Received 3 March 2009
DOI:https://doi.org/10.1103/PhysRevB.80.033412
©2009 American Physical Society