1,161 research outputs found
Calculations of exchange interaction in impurity band of two-dimensional semiconductors with out of plane impurities
We calculate the singlet-triplet splitting for a couple of two-dimensional
electrons in the potential of two positively charged impurities which are
located out of plane. We consider different relations between vertical
distances of impurities and and their lateral distance . Such a
system has never been studied in atomic physics but the methods, worked out for
regular two-atomic molecules and helium atom, have been found to be useful.
Analytical expressions for several different limiting configurations of
impurities are obtained an interpolated formula for intermediate range of
parameters is proposed. The -dependence of the splitting is shown to become
weaker with increasing .Comment: 14 pages, RevTeX, 5 figures. Submitted to Phys Rev.
Photoluminescence Spectroscopy of the Molecular Biexciton in Vertically Stacked Quantum Dot Pairs
We present photoluminescence studies of the molecular neutral
biexciton-exciton spectra of individual vertically stacked InAs/GaAs quantum
dot pairs. We tune either the hole or the electron levels of the two dots into
tunneling resonances. The spectra are described well within a few-level,
few-particle molecular model. Their properties can be modified broadly by an
electric field and by structural design, which makes them highly attractive for
controlling nonlinear optical properties.Comment: 4 pages, 5 figures, (v2, revision based on reviewers comments,
published
Anharmonic properties of double giant dipole resonance
A systematic microscopic study of the anharmonic properties of the double
giant dipole resonance (DGDR) has been carried out, for the first time, for
nuclei with mass number spanning the whole mass table. It is concluded that
the corrections of the energy centroid of the and
components of the DGDR from its harmonic limit are negative, have a value of
the order of few hundred keV and follow an dependence.Comment: 4 pages, 2 figure
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