160 research outputs found
Mass deformed world-sheet action of semi-local vortices
The mass deformed effective world-sheet theory of semi local vortices was
constructed via the field theoretical method. By Euler-Lagrangian equations,
the Ansatze for both the gauge field and the adjoint scalar were solved, this
ensures that zero modes of vortices are minimal excitations of the system. Up
to the order, all profiles are solved. The mass deformed effective
action was obtained by integrating out the transverse plane of the vortex
string. The effective theory interpolates between the local vortex and the
lump. Respecting certain normalization conditions, the effective theory shows a
Seiberg-like duality, which agrees with the result of the K\"ahler quotient
construction.Comment: 22 pages, non figures. Comments are welcome
Toda chain from the kink-antikink lattice
In this paper, we have studied the kink and antikink solutions in several
neutral scalar models in 1+1 dimension. We follow the standard approach to
write down the leading order and the second order force between long distance
separated kink and antikink. The leading order force is proportional to
exponential decay with respect to the distance between the two nearest kinks or
antikinks. The second order force have a similar behavior with the larger decay
factor, namely . We make use of these properties to construct the
kink lattice. The dynamics of the kink lattice with leading order force can be
identified as ordinary nonperiodic Toda lattice. Also the periodic Toda lattice
can be obtained when the number of kink lattice is even. The system of kink
lattice with force up to the next order corresponds to a new specific
deformation of Toda lattice system. There is no well study on this deformation
in the integrable literatures.We found that the deformed Toda system are near
integrable system, since the integrability are hindered by high order
correction terms. Our work provides a effective theory for kink interactions
and a new near or quasi integrable model.Comment: 20 pages no figure
Near integrability of kink lattice with higher order interactions
In the paper, we make use of Manton's analytical method to investigate the
force between kink and the anti-kink with large distance in dimensional
field theory. The related potential has infinite order corrections of
exponential pattern, and coefficients for each order are determined. These
coefficients can also be obtained by solving the equation of the fluctuation
around the vacuum. At the lowest order, the kink lattice represents the Toda
lattice. With higher order correction terms, the kink lattice can represent one
kind of the generic Toda lattice. With only two sites, the kink lattice is
classically integrable. If the number of sites of the lattice is larger than
two, the kink lattice is not integrable but a near integrable system. We take
use of the Flaschka's variables to study the Lax pair of the kink lattice.
These Flaschka's variables have interesting algebraic relations and the
non-integrability can be manifested. We also discussed the higher Hamiltonians
for the deformed open Toda lattice, which has a similar result as the ordinary
deformed Toda
Strain engineering and photocatalytic application of single-layer ReS
We present a theoretical study on the electronic, dynamical, and
photocatalytic properties of single-layer ReS under uniaxial and shear
strains. The single-layer ReS shows strong anisotropic responses to
straining. It remains dynamically stable for a wide range of -axial strain,
but becomes unstable for 2\% -axial compressive strain. The single-layer
ReS is calculated to be an indirect bandgap semiconductor, and there is an
indirectdirect bandgap transition under 15\% -axial tensile straining.
The single-layer ReS is predicted incapable of catalyzing the water
oxidation reaction. However, 15\% -axial tensile strain can enable the
single-layer ReS for overall photocatalytic water splitting. Besides, the
single-layer ReS can also catalyze the overall water splitting and be most
efficient under acidic water solutions with pH=3.8
Impurity effects on the grain boundary cohesion in copper
Segregated impurities at grain boundaries can dramatically change the
mechanical behavior of metals, while the mechanism is still obscure in some
cases. Here, we suggest an unified approach to investigate segregation and its
effects on the mechanical properties of polycrystalline alloys using the
example of 3 impurities (Mg, Al, Si, P, or S) at a special type tilt grain boundary in Cu. We show that for these impurities
segregating to the grain boundary the strain contribution to the work of grain
boundary decohesion is small and that the chemical contribution correlates with
the electronegativity difference between Cu and the impurity. The strain
contribution to the work of dislocation emission is calculated to be negative,
while the chemical contribution to be always positive. Both the strain and
chemical contributions to the work of dislocation emission generally become
weaker with the increasing electronegativity from Mg to S. By combining these
contributions together we find, in agreement with experimental observations,
that a strong segregation of S can reduce the work of grain boundary separation
below the work of dislocation emission, thus embrittling Cu, while such an
embrittlement cannot be produced by a P segregation because it lowers the
energy barrier for dislocation emission relatively more than for work
separation
Strain-induced stabilization of Al functionalization in graphene oxide nanosheet for enhanced NH3 storage
Strain effects on the stabilization of Al ad-atom on graphene
oxide(GO)nanosheet as well as its implications for NH3 storage have been
investigated using first-principles calculations.The binding energy of Al
ad-atom on GO is found to be a false indicator of its stability.Tensile strain
is found to be very effective in stabilizing the Al ad-atom on GO.It
strengthens the C-O bonds through an enhanced charge transfer from C to O
atoms. Interestingly,C-O bond strength is found to be the correct index for
Al's stability.Optimally strained Al-functionalized GO binds up to 6 NH3
molecules,while it binds no NH3 molecule in unstrained condition.Comment: 11 pages, 3 figures, 4 tables, Applied Physics Letters (Under Review
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