403 research outputs found
Fine structure of exciton excited levels in a quantum dot with a magnetic ion
The fine structure of excited excitonic states in a quantum dot with an
embedded magnetic ion is studied theoretically and experimentally. The
developed theory takes into account the Coulomb interaction between charged
carriers, the anisotropic long-range electron-hole exchange interaction in the
zero-dimensional exciton, and the exchange interaction of the electron and the
hole with the -electrons of a Mn ion inserted inside the dot. Depending on
the relation between the quantum dot anisotropy and the exciton-Mn coupling the
photoluminescence excitation spectrum has a qualitatively different behavior.
It provides a deep insight into the spin structure of the excited excitonic
states.Comment: 6 pages, 6 figure
Antilocalization in Coulomb Blockade
We study the effect of spin-orbit scattering on the statistics of the
conductance of a quantum dot for Coulomb blockade peaks and valleys. We find
the distribution function of the peak heights for strong spin-orbit scattering
in the presence and absence of time reversal symmetry. We find that the
application of a magnetic field suppresses the average peak height, similar to
the antilocalizaion in the bulk systems. For the valleys, we consider the
elastic cotunneling contribution to the conductance and calculate its moments
at the crossover between ensembles of various symmetries.Comment: 4 pages, 2 figure
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