Zeeman-gap anomaly in photoluminescence from a two-dimensional electron gas in CdTe/(Cd, Mg)Te quantum wells

We have investigated photoluminescence spectra from a two-dimensional electron gas in a n-type ${\mathrm{C}\mathrm{d}\mathrm{T}\mathrm{e}/\mathrm{C}\mathrm{d}}_{0.865}{\mathrm{Mg}}_{0.135}\mathrm{Te}$ single quantum well in magnetic fields up to 14 T at low temperatures. High-mobility two-dimensional carriers in this system exhibited photoluminescence oscillation and splitting in accordance with the Landau filling factor. The pronounced spectral anomaly especially near at odd filling factor suggests the importance of the spin degree of freedom. The observed spectra exhibited the behavior predicted by a calculation by Hawrylak and Potemski [Phys. Rev. B 56, 12 386 (1997)] taking account of Auger and spin-flip recombination processes. Temperature as well as excitation power dependence of this anomalous photoluminescence peaks was investigated.