S. Huant

Publications (4)1.72 Total impact

• Article: Shallow donor spectroscopy and polaron coupling in Ga0.47In0.53As

  R J Nicholas, C K Sarkar, L C Brunel, S Huant, J C Portal, M Razeghi, J Chevrier, J Massies, H M Cox
  [show abstract] [hide abstract]
  ABSTRACT: An investigation of shallow donor energy levels in magnetic fields in the ternary alloy Ga0.47In0.53As, lattice matched to InP, has been made. Transitions between 1s and 2p energy levels of shallow hydrogenic donors have been observed in photoconductivity as a function of magnetic field. Transition energies and their magnetic field dependence are well predicted by the use of an effective Rydberg, however it is found that the 1s to 2p+ transition energy deviates from the theoretical value at high fields. This clearly indicates strong polaron pinning of the 2p+ level to two LO phonon modes which are 'GaAs'-like and 'InAs'-like, arising from the GaInAs.
  Journal of Physics C Solid State Physics 11/2000; 18(15):L427.
• Article: A study of n-type GaxIn1-xAsyP1-y-InP quantum wells

  J C Portal, R J Nicholas, M A Brummell, L C Brunel, S Huant, M Razeghi, M Laviron
  [show abstract] [hide abstract]
  ABSTRACT: The properties of GaInAsP-InP single- and multiple-quantum-well structures have been studied using the Shubnikov-de Haas effect and cyclotron and magnetophonon resonance techniques. The effective mass of the two-dimensional electrons has been measured and the two-dimensional carrier concentrations determined. There is evidence for the formation of a 'depleted superlattice' in the multiple-quantum-well structures, in which most or all of the electrons accumulate at a single interface.
  Semiconductor Science and Technology 12/1998; 1(1):3. · 1.72 Impact Factor
• Article: Frequency shifted polaron coupling in GaInAs heterostructures

  L.C. Brunel, S. Huant, R.J. Nicholas, M.A. Hopkins, M.A. Brummell, K. Karrai, J.C. Portal, M. Razeghi, K.Y. Cheng, A.Y. Cho
  [show abstract] [hide abstract]
  ABSTRACT: Frequency dependent cyclotron resonance measurements are reported on Ga0.47In0.53AsInP and Ga0.47In0.53AsAl0.48In0.52As heterostructures. Discontinuities in the effective mass are observed at two frequencies, due to resonant polaron coupling to the two optic phonon modes in GaInAs. In heterojunctions the coupling occurs at the frequencies of the TO phonons, in contrast to bulk materials, and the relative strength of the coupling to the two modes is different in the two systems. In more lightly doped superlattices the coupling is stronger, leading to larger shifts in the effective mass, and occurs at the LO phonon frequencies. This behaviour is discussed in terms of possible changes in the screening and polarisation of the optic phonon modes.
  Surface Science.
• Article: Cyclotron resonance and polaron effects in a two-dimensional electron gas in GaInAs

  M.A. Brummell, R.J. Nicholas, L.C. Brunel, S. Huant, M. Baj, J.C. Portal, M. Razeghi, M.A. Di Forte-Poisson, K.Y. Cheng, A.Y. Cho
  [show abstract] [hide abstract]
  ABSTRACT: Cyclotron resonance results from GaInAs-InP heterojunctions and superlattices and GaInAs-AlInAs heterojunctions in fields up to 18 T are reported. For low frequencies, the effective mass is compared with the predictions of k · p theory, and the resonance linewidth is fitted to finite range scattering theories. At higher frequencies, the linewidth increases dramatically, while the effective mass deviates from its low-frequency value. These effects are attributed to resonant polaron coupling.
  Surface Science.