We found that a downwardly concave entanglement evolution of the ground state of a two-electron axially symmetric quantum dot testifies that a shape transition from a lateral to a vertical localization of two electrons under a perpendicular magnetic
field takes place. Although affected, the two-electron probability density does not exhibit any prominent change.
We use the entanglement measure to study the evolution of quantum correlations in two-electron axially-symmetric parabolic quantum dots under a perpendicular magnetic field. We found that the entanglement indicates on the shape transition in the dens
ity distribution of two electrons in the lowest state with zero angular momentum projection at the specific value of the applied magnetic field.
Narrow optical band pass filters are widely used in systems with optical processing of information, color displays development and optical computers. We show that such ultra filters can be created by means of nanoparticles which consist of a dielectr
ic sphere and a metallic shell. The components can be adjusted such that there is a remarkable transparency at the desired wavelength range, while a strong absorption takes place outside of this region.
Using the exactly solvable excitation spectrum of two-electron quantum dots with parabolic potential, we show that the inclusion of the vertical extension of the quantum dot provides a consistent description of the experimental findings of Nishi et a
l. [Phys.Rev.B75, 121301(R) (2007)]. We found that the second singlet-triplet transition in the ground state is a vanishing function of the lateral confinement in the three-dimensional case, while it always persists in the two-dimensional case. We show that a slight decrease of the lateral confinement leads to a formation of the Wigner molecule at low magnetic fields.
