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[ISSP Colloquiums]
Thin Film Electronic Structure: Beyond the Particle
Title : Thin Film Electronic Structure: Beyond the Particle
Date :
Time :
2008/5/27(Tue)
2:00 PM -  
Place : Lecture Room (A632), 6th Floor, ISSP   
Lecturer : Prof. Tai C. Chiang
Affiliation : Department of Physics, University of Illinois
Summary : The quantization of electronic states in thin metallic films is now well-established, having been observed in a number of systems including films on metal as well as semiconductor substrates. The impact of this quantization on the films' physical properties has been demonstrated in a number of studies, including the dependence on thickness of films' thermal stabilities, work functions, and superconducting transition temperatures. In the simplest model, the electrons are confined to the film by the substrate and vacuum interfaces, which act as mirrors to reflect the electrons back into the film, resulting in discrete standing-wave states. In this picture, the substrate forms a reflecting barrier due to a mismatch of electronic structures between it and the overlayer. This talk will present photoemission results from a variety of thin-film systems that show more interesting electronic structures due to interactions with the substrate and interface. The systems studied highlight various effects, including interfacial scattering and diffraction, hybridization of film and substrate states, and the formation of a composite quantum well from a thin metallic film on a semiconductor substrate. In the latter case, the semiconductor depletion region forms part of the quantum well system via coherent coupling between the film and substrate electronic states.

In collaboration with S. J. Tang, N. J. Speer, Y. Liu, D. Ricci, M. Upton, L. Basile, S.-L. Chang, Y.-R. Lee, and T. Miller
Contact : Iwao Matsuda (ext.63402)