7,276 research outputs found
Magneto-chiral scattering of light: a new optical manifestation of chirality
We have investigated multiple scattering of light in systems subject to
magneto-chiral (MC) effects. Our medium consists of magneto-optically active
dipoles placed in a chiral geometry under the influence of an external magnetic
field. We have calculated, for the first time, the total and the differential
scattering MC cross sections of this system, explicitely showing that they are
proportional to pseudoscalar quantities. This provides a new optical measure
for the degree of chirality, a pseudoscalar g, of an arbitrary geometrical
configuration of scatterers based on its scattering properties. We have
calculated g for some simple chiral systems and we have even used it to probe
the degree of optical chirality of random systems. Finally, we have compared
with other recently defined chiral measures in literature.Comment: 18 pages, 6 figures, RevTeX. Submitted to PR
Explosion of smoothness for conjugacies between multimodal maps
Let and be smooth multimodal maps with no periodic attractors and no
neutral points. If a topological conjugacy between and is
at a point in the nearby expanding set of , then is a smooth
diffeomorphism in the basin of attraction of a renormalization interval of .
In particular, if and are unimodal maps and
is at a boundary of then is in .Comment: 22 page
Adiabatic Charge Pumping through Quantum Dots in the Coulomb Blockade Regime
We investigate the influence of the Coulomb interaction on the adiabatic
pumping current through quantum dots. Using nonequilibrium Green's functions
techniques, we derive a general expression for the current based on the
instantaneous Green's function of the dot. We apply this formula to study the
dependence of the charge pumped per cycle on the time-dependent pumping
potentials. The possibility of charge quantization in the presence of a finite
Coulomb repulsion energy is investigated in the light of recent experiments.Comment: 11 pages, 10 figure
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