Interface local spin states in a CdTe/(Cd, Mn)Te quantum well

Magneto-photoluminescence spectra obtained experimentally for a 1.9 nm thick CdTe quantum well with semi-magnetic barriers of Cd1-xMnxTe (x = 0.24) in the range of a magnetic field B = 0-50 T and applied pressure up to 1.5 GPa have been analyzed through the interface delta -potential model. In the model, the interface potential is expressed as A sigma delta (z +/- L-w/2), where a is the spin projection +/-1/2 and L-w is the quantum well width. Our results show that the amplitude of the interface potential A is saturated at 15 T and is not changed up to 50 T. This behavior is described well by the modified Brillouin function, which suggests that the magnetic ions in the interface region are isolated rather than clustered, in contrast to those: in the barrier layers. The potential amplitude A is found to be enhanced by the pressure. (C) 2001 Elsevier Science B.V. All rights reserved.