767 research outputs found
Covariant theory of particle-vibrational coupling and its effect on the single-particle spectrum
The Relativistic Mean Field (RMF) approach describing the motion of
independent particles in effective meson fields is extended by a microscopic
theory of particle vibrational coupling. It leads to an energy dependence of
the relativistic mass operator in the Dyson equation for the single-particle
propagator. This equation is solved in the shell-model of Dirac states. As a
result of the dynamics of particle-vibrational coupling we observe a noticeable
increase of the level density near the Fermi surface. The shifts of the
single-particle levels in the odd nuclei surrounding 208-Pb and the
corresponding distributions of the single-particle strength are discussed and
compared with experimental data.Comment: 27 pages, 8 figure
Optical Study of GaAs quantum dots embedded into AlGaAs nanowires
We report on the photoluminescence characterization of GaAs quantum dots
embedded into AlGaAs nano-wires. Time integrated and time resolved
photoluminescence measurements from both an array and a single quantum
dot/nano-wire are reported. The influence of the diameter sizes distribution is
evidenced in the optical spectroscopy data together with the presence of
various crystalline phases in the AlGaAs nanowires.Comment: 5 page, 5 figure
Manifestation of interface anisotropy in CdTe quantum wells
Photoluminescence and polarized reflection spectra of quantum well structures
with symmetric CdZnTe/CdTe/CdZnTe and
asymmetric CdZnTe/CdTe/CdMgTe barriers were
studied. The Stokes parameters of the reflected light from these structures
were measured. In the structures with symmetric barriers, exciton resonances
were found in the reflection spectra and were not present in the
photoluminescence spectra. In structures with asymmetric barriers, in the
region of exciton resonances, the phenomenon of light birefringence was
detected, caused by a lower symmetry of the interfaces compared to the symmetry
of bulk crystals. A discussion of both phenomena was given
Self-consistent calculations of quadrupole moments of the first 2+ states in Sn and Pb isotopes
A method of calculating static moments of excited states and transitions
between excited states is formulated for non-magic nuclei within the Green
function formalism. For these characteristics, it leads to a noticeable
difference from the standard QRPA approach. Quadrupole moments of the first 2+
states in Sn and Pb isotopes are calculated using the self-consistent TFFS
based on the Energy Density Functional by Fayans et al. with the set of
parameters DF3-a fixed previously. A reasonable agreement with available
experimental data is obtained.Comment: 5 pages, 6 figure
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