22,847 research outputs found
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
Chiral odd GPDs in transverse and longitudinal impact parameter spaces
We investigate the chiral odd generalized parton distributions (GPDs) for
non-zero skewness in transverse and longitudinal position spaces by
taking Fourier transform with respect to the transverse and longitudinal
momentum transfer respectively. We present overlap formulas for the chiral-odd
GPDs in terms of light-front wave functions (LFWFs) of the proton both in the
ERBL and DGLAP regions. We calculate them in a field theory inspired model of a
relativistic spin 1/2 composite state with the correct correlation between the
different LFWFs in Fock space, namely that of the quantum fluctuations of an
electron in a generalized form of QED. We show the spin-orbit correlation
effect of the two-particle LFWF as well as the correlation between the
constituent spin and the transverse spin of the target.Comment: 1 figure and references added, typos corrected. version to appear in
Phys.Rev.
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