TRIPLET TRANSITIONS OF D- CENTERS IN QUANTUM-WELLS IN HIGH MAGNETIC-FIELDS

The spin-singlet and spin-triplet optical transitions of negative dono r centers D- in GaAs/(Al,Ga)As quantum wells in high magnetic fields a re considered both theoretically and experimentally. The measured and calculated transition energies are shown to be in very good agreement for the D- singlet transition (1%). The two strong triplet transitions that are predicted by theory are ndt observed in the experiment. This is thought to be due to accidental energy coincidences with one-parti cle excitations such as the electron cyclotron resonance and the 1s -- > 2p(+) transition of neutral donors.