27,303 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
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
Observation of robust flat-band localization in driven photonic rhombic lattices
We demonstrate that a flat-band state in a quasi-one-dimensional rhombic
lattice is robust in the presence of external drivings along the lattice axis.
The lattice was formed by periodic arrays of evanescently coupled optical
waveguides, and the external drivings were realized by modulating the paths of
the waveguides. We excited a superposition of flat-band eigenmodes at the input
and observed that this state does not diffract in the presence of static as
well as high-frequency sinusoidal drivings. This robust localization is due to
destructive interference of the analogous wavefunction and is associated with
the symmetry in the lattice geometry. We then excited the dispersive bands and
observed Bloch oscillations and coherent destruction of tunneling.
{\textcopyright} 2017 Optical Society of America.Comment: 5 pages, 7 figure
Electrostatic contribution to DNA condensation - application of 'energy minimization' in a simple model in strong Coulomb coupling regime
Bending of DNA from a straight rod to a circular form in presence of any of
the mono-, di-, tri- or tetravalent counterions has been simulated in strong
Coulomb coupling environment employing a previously developed energy
minimization simulation technique. The inherent characteristics of the
simulation technique allow monitoring the required electrostatic contribution
to the bending. The curvature of the bending has been found to play crucial
roles in facilitating electrostatic attractive potential energy. The total
electrostatic potential energy has been found to decrease with bending which
indicates that bending a straight DNA to a circular form or to a toroidal form
in presence of neutralizing counterions is energetically favorable and
practically is a spontaneous phenomenon
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