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Full-Text Articles in Engineering
Magnetic-Field-Induced Indirect Gap In A Modulation-Doped Quantum Well , D. M. Whittaker, T. A. Fisher, Philip E. Simmonds, M. S. Skolnick, R. Smith
Magnetic-Field-Induced Indirect Gap In A Modulation-Doped Quantum Well , D. M. Whittaker, T. A. Fisher, Philip E. Simmonds, M. S. Skolnick, R. Smith
Faculty of Engineering - Papers (Archive)
We report the first experimental evidence for the indirect fundamental band gap developed when an in-plane magnetic field is applied to a modulation-doped quantum well. The observed photoluminescence peak for the lowest subband undergoes a large, approximately quadratic shift with field, a consequence of the behavior of the allowed transitions in the increasingly indirect-gap band-structure. A good theoretical fit is obtained by calculating the transition energies using a realistic self-consistent Hartree potential for the quantum-well profile.
Fermi-Energy-Edge Singularity In Quantum Wells Containing More Than One Occupied Subband , M. S. Skolnick, D. M. Whittaker, Philip E. Simmonds, T. A. Fisher, M. K. Saker, J. M. Rorison, R. S. Smith, P. B. Kirby, C. R. White
Fermi-Energy-Edge Singularity In Quantum Wells Containing More Than One Occupied Subband , M. S. Skolnick, D. M. Whittaker, Philip E. Simmonds, T. A. Fisher, M. K. Saker, J. M. Rorison, R. S. Smith, P. B. Kirby, C. R. White
Faculty of Engineering - Papers (Archive)
A study of the Fermi-energy-edge singularity in asymmetric modulation-doped quantum wells is reported. It is shown that high densities of free carriers in filled n=1 electron subbands have no significant influence on the edge singularity in partly occupied n=2 subbands, demonstrating the weakness of intersubband Coulomb-scattering processes. The enhancement of oscillator strength at the Fermi energy is of very similar magnitude to that for excitonic transitions in undoped quantum wells.