Nonlinear dependence of the magnetophotoluminescence energies of asymmetricGaAs∕Ga0.67Al0.33Asquantum wells on an external magnetic field

Abstract

Nonlinear dependence of the magnetophotoluminescence ͑MPL͒ energies in modulation-doped asymmetric GaAs/ Ga 0.67 Al 0.33 As quantum wells of different widths are investigated experimentally and theoretically as functions of an external magnetic field. The investigated structures have only one electric subband populated with electrons. Contrary to the theoretical descriptions existing in the literature and based on the oscillations of screening, the observed maxima of MPL energies do not occur at integer filling factors and do not change into minima for higher well widths. We interpret our observations assuming that the oscillations of MPL energies are due to an oscillatory electron transfer between a GaAs well and a reservoir outside the well. We obtain a very good description of the experimental data concerning both the maxima positions and the oscillation amplitudes for different well widths and electron densities. Our interpretation is corroborated by the quantum Hall data obtained on the same samples.

Reservoir model for two-dimensional electron gases in quantizing magnetic fields: A review

“…Also the details of the description coincide, as discussed in Ref. . It was concluded that the nonlinearities in the PLM energies were caused by the electron density oscillations resulting from the presence of a reservoir.…”

“…For these reasons the problem of interband MPL nonlinearities was reconsidered by Zawadzki et al [14] with the use of the reservoir model (see also Kamal-Saadi et al [47]). Below we briefly summarize the main points of this analysis.…”

“…[6,7]. Still, the reservoir model has kept appearing in the literature under different names in order to explain various observations on the 2D electron gases: quantum transport [8][9][10], Fermi energy behaviour [11], cyclotron resonance [12,13], interband photo-magneto-luminescence [14], magnetic susceptibilities [15], magneto-plasmon dispersion [16,17], etc. In his well known book, Mahan [18] treats the localization and reservoir interpretations of QHE on equal footing.…”

Conduction electrons in acceptor-doped GaAs/GaAlAs heterostructures: a review

“…This is typical for 2D structures and has been explained by electron density oscillations in the quantum well, see Ref. [14]. The solid lines without oscillations are drawn using heavy-hole LLs [15] and GaAs conduction LLs taking into account weak band's nonparabolicity [16,17].…”

Enhanced magneto-optical oscillations from two-dimensional hole-gases in the presence of Mn ions

“…[4][5][6][7][8][9][10][11] Most of the letters present oscillations of the optical emission intensity and the peak energy, and there are some few polarization-resolved results concerning oscillations of the spin-splitting energy. Magneto-optical results from a series of samples with different Mn concentrations revealed an anomalous oscillation of the InGaAs QW emission as a function of the magnetic field, including both the peak and the spin-splitting energies.…”