1,882 research outputs found
On the simplest (2+1) dimensional integrable spin systems and their equivalent nonlinear Schr\"odinger equations
Using a moving space curve formalism, geometrical as well as gauge
equivalence between a (2+1) dimensional spin equation (M-I equation) and the
(2+1) dimensional nonlinear Schr\"odinger equation (NLSE) originally discovered
by Calogero, discussed then by Zakharov and recently rederived by Strachan,
have been estabilished. A compatible set of three linear equations are obtained
and integrals of motion are discussed. Through stereographic projection, the
M-I equation has been bilinearized and different types of solutions such as
line and curved solitons, breaking solitons, induced dromions, and domain wall
type solutions are presented. Breaking soliton solutions of (2+1) dimensional
NLSE have also been reported. Generalizations of the above spin equation are
discussed.Comment: 32 pages, no figures, accepted for publication in J. Math. Phy
A (2+1) dimensional integrable spin model: Geometrical and gauge equivalent counterpart, solitons and localized coherent structures
A non-isospectral (2+1) dimensional integrable spin equation is investigated.
It is shown that its geometrical and gauge equivalent counterparts is the (2+1)
dimensional nonlinear Schr\"odinger equation introduced by Zakharov and studied
recently by Strachan. Using a Hirota bilinearised form, line and curved soliton
solutions are obtained. Using certain freedom (arbitrariness) in the solutions
of the bilinearised equation, exponentially localized dromion-like solutions
for the potential is found. Also, breaking soliton solutions (for the spin
variables) of the shock wave type and algebraically localized nature are
constructed.Comment: 14 pages, LaTex, no figures; email of first author:
[email protected] and [email protected]
Influence of field-like torque in synchronization of spin torque oscillators
The magnetization dynamics of two parallelly coupled spin torque oscillators,
destabilization of steady states and removal of multistability, are
investigated by taking into account the influence of field-like torque. It is
shown that the existence of such torque can cancel the effect of damping and
can, therefore, cause the oscillators to exhibit synchronized oscillations in
response to direct current. Further, our results show that the presence of
field-like torque enhances the power and Q-factor of the synchronized
oscillations. The validity of the above results is confirmed by numerical and
analytical studies based on the stochastic Landau-Lifshitz-Gilbert-Slonczewski
equation.Comment: 10 pages, 10 figures, Accepted for Publication in IEEE Transactions
on Magnetic
Integrable (2+1)-Dimensional Spin Models with Self-Consistent Potentials
Integrable spin systems possess interesting geometrical and gauge invariance
properties and have important applications in applied magnetism and
nanophysics. They are also intimately connected to the nonlinear Schr\"odinger
family of equations. In this paper, we identify three different integrable spin
systems in (2 + 1) dimensions by introducing the interaction of the spin field
with more than one scalar potential, or vector potential, or both. We also
obtain the associated Lax pairs. We discuss various interesting reductions in
(2 + 1) and (1 + 1) dimensions. We also deduce the equivalent nonlinear
Schr\"odinger family of equations, including the (2 + 1)-dimensional version of
nonlinear Schr\"odinger--Hirota--Maxwell--Bloch equations, along with their Lax
pairs.Comment: 21 page
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