Inhibition of spontaneous emission from quantum-well magnetoexcitons

We propose a method for tailoring the radiative properties of two-dimensional magnetoexcitons. First, we show that the magnetoexciton-photon coupling is purely bilinear in the strong-magnetic-field limit, implying that optical nonlinearities appear through the breakdown of bosonic commutation relations at high densities. The dispersion curve of magnetoexcitons may be modified or engineered using external electric or optical fields. We show that the application of an in-plane electric field will render the ground-state magnetoexcitons stable against radiative recombination, as a result of the momentum conservation. Based on this effect, we propose a particular geometry which should allow for the investigation of condensation effects and superfluidity in direct-band-gap semiconductors. {} 1996 The American Physical Society.