Exciton condensation in semimagnetic CdTe/CdMnTe multiple quantum wells

The exciton condensation in a magnetic field, parallel to the interfaces, t unable type-I/type-II multiple quantum well structure made by semimagnetic materials of CdTe/CdMnTe has been investigated theoretically. In the type-I I regime, the magnetic field results in suppression of exciton condensation , which in turn is attributed to the field-induced polarization of exciton, the increases of magnetic confinements and interacting strengths of electr ons and holes. Detailed calculations show an similar to 10 meV insulating g ap in the case of B = 20 T and n approximate to 16 x 10(10) cm(-2), and exh ibit a transition from Bose-Einstein condensation to BCS condensed phase wi th increased excitonic density. (C) 2001 Published by Elsevier Science B.V.