MAGNETOOPTICAL STUDY OF INTERWELL COUPLING IN DOUBLE-QUANTUM WELLS USING DILUTED MAGNETIC SEMICONDUCTORS

Magneto-optical experiments were carried out on a series of ZnSe/Zn1-y CdySe double quantum wells coupled by Zn1-xMnxSe diluted magnetic semi conductor (DMS) barriers. The samples consisted of 45-Angstrom nonmagn etic quantum wells with interwell DMS barriers of different thicknesse s (10, 35, and 100 Angstrom). The interband ground-state transition, a s well as interband transitions between excited states, were observed. As the magnetic field is applied, the heights of the magnetic barrier s in the conduction and in the valence band undergo Zeeman shifts, cau sing major changes in the interwell coupling. Such changes were studie d by examining the energies of the transitions, their Zeeman splitting s, and their intensities. The dependence of these effects was further studied as a function of temperature and barrier width. The behavior o bserved in those cases involving ultrathin magnetic barriers was found to be anomalous, and is discussed in terms of effects of reduced dime nsionality on the magnetic properties of thin DMS layers.