Atomic Wires on Surfaces: metal-insulating transitions and electron correlation

Prof. H. W. Yeom

Director, Center for Atomic Wires and Layers, Department of Physics, Yonsei University, Korea (Visiting Professor of Tohoku University)

Date + Time: July 22nd, 16:00-17:00

Place: UVSOR Build. #304 (UVSOR Seminar room)

Abstract:
During last ten years, we have studied the electronic structures of metallic atomic wire arrays self-assembled on silicon surfaces [1-8]. The motivations are twofold; (i) these systems might be exploited in future nano- or molecular-scale device architectures and (ii) they may be useful as a new class of model systems for the investigation of physics of low dimensional electrons. The systems investigated are 4x1-In [1-3], 5x2-Au [4, 5] reconstructions on flat Si(111) and Au-induced 1D structures on vicinal Si(111) such as Si(553), Si(557), and Si(5 5 12) [6, 7]. These systems feature well-defined 1D electron bands with partial fillings and Peierls-type metal-insulator transitions by strong electron-lattice interactions [1-3, 6, 7]. The importance of defects was also noticed and the controllable defect could be used to tune the electronic bands systematically [4, 5]. Very recently, we also found the signatures of electron correlation, which leads to the non Fermi liquid behaviors as expected for 1D metal [8, 9].

References
[1] H. W. Yeom et al., PRL 82, 4898 (1999).
[2] J. R. Ahn et al., PRL 93, 106401 (2004).
[3] S. J. Park et al., PRL 95, 126102 (2005).
[4] W. H. Choi et al., PRL 100, 126801 (2008).
[5] P. G. Kang et al., PRL 100, 146103 (2008).
[6] J. R. Ahn et al., PRL 95, 196402 (2005).
[7] J. R. Ahn et al., PRL 91, 196403 (2003).
[8] K. S. Kim et al., PRL 99, 196804 (2007).
[9] K. S. Kim et al., PRL, submitted (2008).
[10] S. H. Kim et al., PRB, submitted (2008).
[11] S. H. Kim et al., to be submitted (2008).