Response of energy levels and wavefunctions of 2-D artificial atoms to changes in parameters in the hamiltonian

Abstract

We explore the pattern of evolution of energy levels and wavefunctions in a harmonically confined single electron artificial atom in 2 dimensions, in the presence of a perpendicular magnetic field and anharmonic perturbations. A configuration interaction (CI) type of approach in a basis of appropriate harmonic oscillator eigenfunctions is used, leading to a complex sparse hermitian matrix eigenvalue problem. We show that for a given strength of the confining potential descriptors like quantum information entropy, level spacing distribution, degree of localization of one electron density and probability current point to a threshold value for the cyclotron frequency (ω_c), beyond which there appears to be a transition from a delocalized description rather than a localized one. No signature of quantum chaos is detected.