EXCITONS IN CD1-XMNXTE QUANTUM-WELLS WITH A PARABOLIC CONFINING POTENTIAL

Excitons in Cd1-xMnxTe and Cd1-x-yMgyMnyTe parabolic and half-paraboli c quantum wells are investigated by magnetooptical methods. The diagon al and nondiagonal(in the harmonic oscillator quantum numbers) transit ions are observed. Apart from Is excitons we observed also 2s and 3s s tates in the presence of a magnetic field. The results are discussed i n terms of a simple variational calculation of the exciton energy. It is shown that a parabolic confining potential very effectively reduces the dimensionality of the excitons leading to large values of their b inding energy even in relatively wide quantum wells. The truly parabol ic shape of the confining potential in the investigated structures is proved by an analysis of spin splitting of the exciton states. (C) 199 8 Elsevier Science B.V. All rights reserved.