25,212 research outputs found
Some Comments on the Spin of the Chern - Simons Vortices
We compute the spin of both the topological and nontopological solitons of
the Chern - Simons - Higgs model by using our approach based on constrained
analysis. We also propose an extension of our method to the non - relativistic
Chern - Simons models. The spin formula for both the relativistic and
nonrelativistic theories turn out to be structurally identical. This form
invariance manifests the topological origin of the Chern - Simons term
responsible for inducing fractional spin. Also, some comparisons with the
existing results are done.Comment: 12 pages, Late
Dynamics of ion cloud in a linear Paul trap
A linear ion trap setup has been developed for studying the dynamics of
trapped ion cloud and thereby realizing possible systematics of a high
precision measurement on a single ion within it. The dynamics of molecular
nitrogen ion cloud has been investigated to extract the characteristics of the
trap setup. The stability of trap operation has been studied with observation
of narrow nonlinear resonances pointing out the region of instabilities within
the broad stability region. The secular frequency has been measured and the
motional spectra of trapped ion oscillation have been obtained by using
electric dipole excitation. It is applied to study the space charge effect and
the axial coupling in the radial plane.Comment: Colloquium paper, 9 pages, 6 figure
Spin of Chern-Simons vortices
We discuss a novel method of obtaining the fractional spin of abelian and
nonabelian Chern-Simons vortices. This spin is interpreted as the difference
between the angular momentum obtained by modifying Schwinger's energy momentum
tensor by the Gauss constraint, and the canonical (Noether) angular momentum.
It is found to be a boundary term depending only on the gauge field and, hence,
is independent of the matter sector to which the Chern-Simons term couples.
Addition of the Maxwell term does not alter the fractional spin.Comment: 11 pages, Latex file, no figure
Ultrapure glass optical waveguide development in microgravity by the sol-gel process
The alkali-borosilicate system was selected as the glass system for the preparation of ultrapure low loss glasses suitable for optical communication. The effect of different oxide contents on the absorption loss was critically reviewed. One composition was chosen to develop the gel preparation procedure in the alkali-borosilicate system. In addition, several procedures for the preparation of gels based on two different approaches were developed. The influence of different preparation parameters were investigated qualitatively. Several conclusions are drawn from the results
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