485 research outputs found
Non-analytic Vortex Core and a Nonlinear Vortex Flow in Bosonic Superfluids
We analyze the disorder limited motion of quantum vortices in a
two-dimensional bosonic superfluid with a large healing length. It is shown
that the excitations of low-energy degrees of freedom associated with the
non-analytic reconstruction of the vortex core [Ann. Phys. {\bf 346}, 195
(2014)] determine strong non-linear effects in the vortex transport at
velocities much smaller than Landau's critical velocity. Experiments are
suggested to verify our predictions.Comment: 5 pages, 3 figure
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
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