Shakeup processes in the recombination spectra of negatively charged excitons.

We report on shakeup processes in the luminescence spectra of a negatively charged exciton (X) at moderate magnetic fields. These processes manifest themselves as a series of low-energy satellite peaks emerging from the negatively charged exciton line. We analyze the dependence of the X energy on magnetic field. We conclude that at magnetic fields above ;1 T the X structure can be viewed as an electron at the lowest Landau level bound to an exciton. @S0163-1829~96!07520-0#