Ab. Dzyubenko et Ay. Sivachenko, Charged magnetoexcitons in two-dimensions: Magnetic translations and families of dark states, PHYS REV L, 84(19), 2000, pp. 4429-4432
We show that optical transitions of charged excitons in semiconductor heter
ostructures are governed in magnetic fields by a novel exact selection rule
, a manifestation of magnetic translations. It is shown that the spin-tripl
et ground state of the quasi-two-dimensional charged exciton X--a bound sta
te of two electrons and one hole-is optically inactive in photoluminescence
at finite magnetic fields. Internal bound-to-bound X- tripler transition h
as a specific spectral position, below the electron cyclotron resonance, an
d is strictly prohibited in a translationally invariant system. These resul
ts allow one to discriminate between free and disorder-affected charged exc
itons.