Magnetic-field-induced substructures in multiple quantum wells consisting of magnetic and nonmagnetic semiconductor layers

Abstract

We have investigated multiple quantum well systems consisting of diluted magnetic (Zn 1ϪxϪy Cd x Mn y Se) and nonmagnetic (Zn 1Ϫx Cd x Se) semiconductor wells, separated by nonmagnetic ZnSe barriers. By focusing on interband transitions involving the lowest multiplet of states ͑i.e., the ground state split by interwell interactions͒, we were able to study the details of the coupling between the wells. The strongest interaction between the states of each well occurs when the wells are identical ͑i.e., when they are in a resonant condition͒. The coupling between the wells is dramatically reduced in the presence of an external magnetic field, which can change the depth of diluted magnetic semiconductor ͑DMS͒ wells relative to the non-DMS wells via the large Zeeman splitting that occurs in the DMS layers. As soon as the depth of the wells becomes unequal, the multiple quantum well system subdivides into separate subsystems consisting of groups of equal ͑resonant͒ wells, one associated with non-DMS wells, and the other with DMS wells. This is clearly evident both from theoretical investigation and from the observed magnetic-field dependence of the absorption lines associated with the ground-state multiplet.

Influence of inter-dot coupling on spin polarization of carriers in double quantum dots

“…Coupling between electronic states is a fundamental quantum phenomenon which appears in many fields of physics. Since the first observation of such an effect in semiconductor multiple quantum well structures by Dingle et al [1], there has been considerable interest in this phenomenon due to its importance both in fundamental physics and in device applications [2][3][4][5][6][7][8].…”

Spin polarization and spin-dependent transmittance in II–VI diluted magnetic semiconductorheterostructure

“…The ternary nature of DMSs makes it possible to alter their material parameters, such as the band gap and/or the lattice constant by varying the composition, i.e., the content of magnetic atoms. This ability to fine-tune lattice parameters of the DMS crystals has allowed researchers to grow quantum wells (QWs) and superlattices in order to investigate new magnetic effects related to low dimensional phenomena [10,11]. Recently, several types of DMS quantum structures have been fabricated [12].…”

Magneto‐photoluminescence study on magnetic/non‐magnetic semiconductor coupled quantum dots

“…Since the first observation of electronic coupling effects in semiconductor multiquantum well structures by Dingle et al [1], there has been a great deal of interest in such quantum phenomenon due to their importance both in fundamental physics and in device applications [2][3][4][5][6][7]. As in quantum wells, the electronic interaction between zero dimensional quantum dot (QD) structures plays an important role for applications.…”