6 research outputs found
Atomic structures beyond the spherical approximation along with PNC as conjectured explanations to Urbach tailing in neutral isolated ytterbium
In this paper, we try to give an explanation to the spectacular Urbach tailing
associated to ytterbium. This rare earth element performs odd spectra due to its
5f-electron shell configuration and complexity of its transition
dynamics within band structure. Ytterbium particular forbidden band alteration has been
associated to two major inconsistencies: calculating atomic single-particle wave functions
and spectra without taking into account the non-spherical effects and neglecting the high
parity non conserving (PNC) amplitudes in ytterbium absorption-emission spectra. The
actual band structure calculation has been achieved within the Hartree-Fock-Slater
approximation. It led to a noticeable blue shift resulting in narrowing the forbidden band
from upper edge. Parity non conserving (PNC) amplitudes were also proposed as an
explanation to width reduction from both upper and lower band edges. The relative extent
of these reductions seems to coincide with Urbach tailing dimensions recorded in recent
studies