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Valley splitting in finite barrier quantum wells
Birck and NCN Publications
  • Timothy B Boykin, Department of Electrical and Computer Engineering, The University of Alabama in Huntsville
  • Neerav Kharche, Birck Nanotechnology Center and Purdue University
  • Gerhard Klimeck, Network for Computational Nanotechnology, School of Electrical and Computer Engineering, Purdue University
Abstract
The valley splitting (VS) in a silicon quantum well is calculated as a function of barrier height with both the multiband sp(3)d(5)s(*) model and a simple two-band model. Both models show a strong dependence of the VS on barrier height. For example, in both models some quantum wells exhibit a sharp minimum in the valley-splitting amplitude as the barrier height is changed. From the simple two-band model we obtain analytic approximations for the phases of the bulk states involved in the valley-split doublet, and from these we show that such sharp minima correspond to parity changes in the ground state as the barrier height is increased. The two-band analytic results show a complicated dependence of the valley splitting on barrier height, with the phases essentially being determined by a competition among effective quantum wells of differing length. These analytic results help explain the VS in realistic structures where different finite barrier heights are possible depending on the confining heterojunctions used.
Date of this Version
6-1-2008
Citation
PHYSICAL REVIEW B 77, 245320
Citation Information
Timothy B Boykin, Neerav Kharche and Gerhard Klimeck. "Valley splitting in finite barrier quantum wells" (2008)
Available at: http://works.bepress.com/gerhard_klimeck/217/