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Full-Text Articles in Engineering
Fermi-Energy Edge Singularity And Excitonic Enhancement Associated With The Second Subband In Asymmetric Modulation-Doped Quantum Wells , T. A. Fisher, Philip E. Simmonds, M. S. Skolnick, A. D. Martin, R. S. Smith
Fermi-Energy Edge Singularity And Excitonic Enhancement Associated With The Second Subband In Asymmetric Modulation-Doped Quantum Wells , T. A. Fisher, Philip E. Simmonds, M. S. Skolnick, A. D. Martin, R. S. Smith
Faculty of Engineering - Papers (Archive)
A study of the Fermi-energy edge singularity (FEES) in the second (n=2) subband of asymmetric modulation-doped (AlGa)As-(InGa)As-GaAs quantum wells (AMDQW’s) is reported. In one of the AMDQW’s a Schottky gate is employed to vary the electron density in the n=2 subband (ns,2) from 0 to 1×1011 cm-2. Temperature-dependent photoluminescence excitation (PLE) measurements clearly show that the n=2 PLE feature has FEES character for ns,2≳0.4×1011 cm-2. In contrast to PLE, photoluminescence (PL) intensity is not a true measure of oscillator strength, since PL intensity can be affected by competing recombination pathways. Temperature-dependent PL measurements have been performed on two types of …
Hartree-Fock Method Posed As A Density-Functional Theory: Application To The Be Atom, A. Holas, N. H. March, Y. Takahashi, C. Zhang
Hartree-Fock Method Posed As A Density-Functional Theory: Application To The Be Atom, A. Holas, N. H. March, Y. Takahashi, C. Zhang
Faculty of Engineering - Papers (Archive)
The Hartree-Fock ground-state energy and electron density are first shown to be derivable from a local one-body effective potential v(r). As a nontrivial example, attention is then focused on the Be atom and isoelectronic atomic ions, the wave functions being written in terms of the density amplitude and phase. Some related general comments on the two-level one-dimensional system are included; kinetic-energy density is shown to be a local functional of electron density generated by the harmonic-oscillator potential.
Theory Of The Piezo-Zeeman Effect For Shallow Acceptors In Group-Iv Semiconductors , K. J. Duff
Theory Of The Piezo-Zeeman Effect For Shallow Acceptors In Group-Iv Semiconductors , K. J. Duff
Faculty of Engineering - Papers (Archive)
Theory is presented for the energy splittings and transition intensities for a single hole system initially of Td symmetry which is then subject to the simultaneous application of a uniaxial stress and uniform magnetic field. Four combinations of stress and field directions are considered.
Discussion And Authors Closure On Performance Of Test Embankment Constructed To Failure On Soft Clay, Buddhima Indraratna
Discussion And Authors Closure On Performance Of Test Embankment Constructed To Failure On Soft Clay, Buddhima Indraratna
Faculty of Engineering - Papers (Archive)
Extract: RESPONSE TO DISCUSSION BY SlEW-ANN TAN It has been explained in the paper (page 18) that the Cam-clay parameters have been selected so that the undrained experimental stress-strain curve coincides with the undrained predictions from the modified Cam-clay theory. The method of parameter estimation proposed by Britto and Gunn (1987) is most appropriate if the conditions of associated flow rule and the normally consolidated behavior are satisfied... RESPONSE TO DISCUSSION BY E. W. BRAND Brand has correctly recognized the difference between the findings of the current study and previous predictions given elsewhere by Balasubramaniam et al. (1989). The authors …
High-Field Zeeman Effect Of Shallow Acceptors In Germanium , P. Fisher, G. J. Takacs, R. Vickers, A. D. Warner
High-Field Zeeman Effect Of Shallow Acceptors In Germanium , P. Fisher, G. J. Takacs, R. Vickers, A. D. Warner
Faculty of Engineering - Papers (Archive)
Zeeman absorption spectra have been obtained for B and Ga in Ge for B∥〈100〉 in the Voigt configuration with plane-polarized radiation. All twelve allowed transitions were observed for both the G and D lines. The corresponding excited states of these two lines for both impurities behave identically; two recent theoretical results are in good agreement. The measurements are a sensitive probe of the ground states; there are differences between the behavior of these for the two acceptors.
The Concept And Design Of Programmable Array Manipulator, Philip Ciufo, Fazel Naghdy, Christopher D. Cook, Pak Chung Wong
The Concept And Design Of Programmable Array Manipulator, Philip Ciufo, Fazel Naghdy, Christopher D. Cook, Pak Chung Wong
Faculty of Engineering - Papers (Archive)
This paper is the complement to the Programmable Array Manipulator, Part 1. It presents an overview of the R & D program associated with the development of the PAM. The aspects of the control scheme are given as are some experimental results showing the preliminary capabilities of the PAM.