Anderson-Fano resonance and shake-up processes in the magnetophotoluminescence of a two-dimensional electron system

We report an anomalous doublet structure and low-energy satellite in the magnetophotoluminescence spectra of a two-dimensional electron system. The doublet structure moves to higher energy with increasing magnetic field and is most prominent at odd filling factors $\nu =5\mathrm{}$ and $\nu =3.\mathrm{}$ The lower-energy satellite peak tunes to lower energy for increasing magnetic fields between $\nu =6\mathrm{}$ and $\nu =2.\mathrm{}$ These features occur at energies below the fundamental band of recombination originating from the lowest Landau level and display striking magnetic field and temperature dependence that indicates a many-body origin. Drawing on a recent theoretical description of Hawrylak and Potemski [Phys. Rev. B 56, 12 386 (1997)], we show that distinct mechanisms are responsible for each feature.