Charged magnetoexcitons in two-dimensions: magnetic translations and families of dark states
We show that optical transitions of charged excitons in semiconductor heterostructures are governed in magnetic fields by a novel exact selection rule, a manifestation of magnetic translations. It is shown that the spin-triplet ground state of the quasi-two-dimensional charged exciton X--a bound state of two electrons and one hole-is optically inactive in photoluminescence at finite magnetic fields. Internal bound-to-bound X- triplet transition has a specific spectral position, below the electron cyclotron resonance, and is strictly prohibited in a translationally invariant system. These results allow one to discriminate between free and disorder-affected charged excitons.
Dzyubenko
AB
Institut fur Theoretische Physik, J. W. Goethe-Universitat, 60054 Frankfurt, Germany.
Sivachenko
AY