Abstract
A harmonic single electron quantum dot in a spatially periodic magnetic field is investigated. The energy spectrum, magnetization, probability, and current density are studied for varying parameters (i.e., amplitude, wavelength, and phase) of the periodic magnetic field. For wavelengths comparable to the oscillator length of the dot, we observe a rich spectral behavior. For higher field amplitudes and depending on the phase of the field, avoided and exact level crossings dominate the spectrum and quasidegenerate low lying states occur systematically. We employ a simple model for the interpretation of the quasidegeneracies and their impact on the probability and current densities. The latter are very sensitive with respect to the phase of the magnetic field. For wavelengths being small compared to the oscillator length, the impact of the field is very minor, thus the obtained spectrum is approximately that of a pure harmonic oscillator. For large values of the eigenfunctions take up a spatially varying phase and the magnitude of the probability current decreases slowly with increasing . Different from the dot in a homogeneous magnetic field, the magnetization, as a function of the field amplitude, has a minimum, depending on the phase and wavelength of the field.
8 More- Received 2 December 2005
DOI:https://doi.org/10.1103/PhysRevB.73.235346
©2006 American Physical Society