Hydrogenic impurities in GaAs/GaAlAs multi-quantum wells in tilted magnetic fields

Abstract

Far-infrared photoconductivity measurements on a GaAsIGaAIAs multiquantum well sample in which the normal to the plane of the sample is tipped away from the magnetic field direction are reported. In order to explain these results, the model developed previously by the authors involving a matrix diagonalization procedure is expanded and then applied to the experimental results. Good agreement is obtained for angles of tilt up to about 30". It is also shown that the model satisfactorily explains results previously obtained by Mueller et a/,

Quantum well excitons in a high magnetic field

“…In addition to the many variational-type calculations which had been cited in Shi et al [1], alternative theoretical approaches for the related problem of the shallow donor in single quantum well (SQW) and multi-quantum well (MQW) systems have been given. Two of the authors (JLD and CAB) have been involved in a matrix diagonalization procedure developed originally by Dunn and Pearl [5] and extended in Barmby et al [6][7][8][9] for the case of magnetic fields pointing at different angles relative to the QW layers. Another of the authors (BSM) has used analytical methods to study shallow donor impurity states and energy levels in cases of large magnetic fields [10,11].…”

Theoretical calculations of shallow donor impurity states in GaAs/GaAlAs multi-quantum wells with magnetic fields applied parallel to the layers

“…The model chosen for the calculations is based on a matrix di.agon&zation procedure (MDP) developed originally by Dunn ,and Pearl (1991) for magnetic fields directed perpendicular to the layers. Subsequently Barmby et al (1993Barmby et al ( , 1994a extended the model to magnetic fields tilted by an angle 0 to the perpendicular by modifying the choice of basis states. However, the form of the wavefunctions was still principally that for a perpendicular 0953-8984/95/122473+06$19.50 @ 1995 IOP Publishing Ltd field, so the results for large tilt angles are poor.…”