Tailoring the electronic properties of concentric double quantum rings in the presence of a donor impurity

The possibility of tailoring III-V GaAs/Al0.3Ga0.7As concentric double quantum rings (CDQRs) by tuning the central barrier, width, and height of the rings brings out carrier confinement in different regimes, which make them suitable for specific applications. Using variational ansatz, Coulomb interaction and carrier localization in the rings are investigated through calculation of diamagnetism and binding energy of donor for different ring dimensions (both axial and radial). Conspicuous changes occur in the behavior of both binding energy and diamagnetism for different dimensions of the inner and outer rings. Tuning the central barrier below a critical limit favors coupling of the two rings and promotes tunneling. The effect of these modifications on the carrier localization has been investigated, which gives a good insight into selective design of CDQRs for specific applications. Published under license by AIP Publishing.