Symmetric and asymmetric fractal diffusion of electron-hole plasmas in semiconductor quantum wells
17 April 2000
The diffusion of photogenerated electron-hole plasmas in intrinsic InP/InGaAs/InP single quantum wells was investigated by measurements of the photoluminescence intensity profile around the illuminated area. Two kinds of heterostructures were investigated, one grown on InP substrate with the growth face orthogonal to the {[}001] direction, and the other grown on InP substrate two degrees off that orientation. The data show that the particles present a fractal diffusion described by the Levy distribution with the exponent parameter alpha = 1.3. In the tilted heterostructure, the diffusion is asymmetric and the particles density obeys a generalized Levy distribution recently predicted by Chaves {[}Phys. Lett. A 239 (1998) 13]. (C) 2000 published by Elsevier Science B.V. All rights reserved.