Megagauss magnetospectroscopy of EuS/PbS multi-quantum wells

Magnetotransmission studies of EuS/PbS multiquantum wells in magnetic fields up to 200 T and in the temperature range from 5 to 300 K are reported. A series of transitions are observed, which we interpret as cyclotron resonance transitions, i.e., the transitions between the lowest magnetic subbands. With this identification, the positions of observed resonances are satisfactorily described by theory when the quantum well width is larger than 100 Angstrom. For narrower quantum wells, however, the discrepancy between theory and experimental measurements is significant. Possible explanations for this discrepancy are discussed.