1,486 research outputs found
CP_N Solitons in Quantum Hall Systems
We will present here an elementary pedagogical introduction to
solitons in quantum Hall systems. We begin with a brief introduction to both
models and to quantum Hall (QH) physics. Then we focus on spin and
layer-spin degrees of freedom in QH systems and point out that these are in
fact fields for N=1 and N=3. Excitations in these degrees of freedom
will be shown to be topologically non-trivial soliton solutions of the
corresponding field equations. This is followed by a brief summary of
our own recent work in this area, done with Sankalpa Ghosh. [ Invited Plenary
Lecture at the International Conference on Geometry, Integrability and
Nonlinearity in Condensed Matter & Soft Condensed Matter Physics held at
Bansko, Bulgaria, July 15-20, 2001. ]Comment: Standard revtex format, 18 pages, no figure
Quantum Hall Solitons with Intertwined Spin and Pseudospin at $\nu = \ 1$
In this paper we study in detail different types of topological solitons
which are possible in bilayer quantum Hall systems at filling fraction
when spin degrees of freedom are included. Starting from a microscopic
Hamiltonian we derive an effective energy functional for studying such
excitations. The gauge invariance and character of this energy
fuctional and their consequences are examined. Then we identify permissible
classes of finite energy solutions which are topologically non-trivial. We also
numerically evaulate a representative solution in which a pseudospin (layer
degrees of freedom) bimeron in a given spin component is intertwined with
spin-skyrmions in each layer, and and discuss whether it is energetically
favoured as the lowest lying excitation in such system with some numerical
results.Comment: Revised version with more numerical results one more figure and table
added. Total 32 pages,6 Postscript figures. Correspondence to
[email protected]
Meron Pseudospin Solutions in Quantum Hall Systems
In this paper we report calculations of some pseudospin textures for bilayer
quantum hall systems with filling factor . The textures we study are
isolated single meron solutions. Meron solutions have already been studied at
great length by others by minimising the microscopic Hamiltonian between
microscopic trial wavefunctions. Our approach is somewhat different. We
calculate them by numerically solving the nonlinear integro -differential
equations arising from extremisation of the effective action for pseudospin
textures. Our results can be viewed as augmenting earlier results and providing
a basis for comparison.Our differential equation approach also allows us to
dilineate the impact of different physical effects like the pseudospin
stiffness and the capacitance energy on the meron solution.Comment: 17 pages Revtex+ 4 Postscript figures; To appear in Int. J. Mod.
Phys.
Near Horizon Superspace
The adS_{p+2} x S^{d-p-2} geometry of the near horizon branes is promoted to
a supergeometry: the solution of the supergravity constraints for the vielbein,
connection and form superfields are found. This supergeometry can be used for
the construction of new superconformal theories. We also discuss the
Green-Schwarz action for a type IIB string on adS_5 x S_5.Comment: 11 pages, LaTe
Stability analysis for soliton solutions in a gauged CP(1) theory
We analyze the stability of soliton solutions in a Chern-Simons-CP(1) model.
We show a condition for which the soliton solutions are stable. Finally we
verified this result numerically.Comment: 13 pages, numerical analysis is added. To be published in Mod. Phys.
Lett.
Effective action of a five-dimensional domain wall
We calculate the four-dimensional low-energy effective action for the
perturbations of a two-scalar domain wall model in five dimensions. Comparison
of the effective action to the Nambu-Goto action reveals the presence of an
additional coupling between the light scalar field and the massless translation
mode (branon excitation), which can be written in terms of the curvature scalar
of the induced metric. We comment on the impact of this interaction to branon
physics.Comment: 24 page
- …