18 research outputs found
Quantum Hall Effect induced by electron-electron interaction in disordered GaAs layers with 3D spectrum
It is shown that the observed Quantum Hall Effect in epitaxial layers of
heavily doped n-type GaAs with thickness (50-140 nm) larger the mean free path
of the conduction electrons (15-30 nm) and, therefore, with a three-dimensional
single-particle spectrum is induced by the electron-electron interaction. The
Hall resistance R_xy of the thinnest sample reveals a wide plateau at small
activation energy E_a=0.4 K found in the temperature dependence of the
transverse resistance R_xx. The different minima in the transverse conductance
G_xx of the different samples show a universal temperature dependence
(logarithmic in a large range of rescaled temperatures T/T_0) which is
reminiscent of electron-electron-interaction effects in coherent diffusive
transport.Comment: 6 pages, 3 figures, 1 tabl
Quantum Hall effect induced by electron-electron interaction in disordered GaAs layers with a three-dimensional spectrum.
Forward Raman scattering in GaAs/AlAs superlattices: Study of optical phonon anisotropy
We present the forward Raman scattering study of zone-centre optical phonon anisotropy
in short-period GaAs/AlAs superlattices. Experiments were performed on specially
prepared superlattice structures having anti-reflection dielectric coatings and
removed substrates. The experimental data are compared with the angular dispersion of
superlattice optical phonons calculated within the dielectric susceptibility model.
We have found a good agreement between the experimental data and the calculations
taking into account interface disorder