11,077 research outputs found
Field - Effect Switching in Nano-Graphite Films
The effect of electrical resistivity switching in nanographite films is
described. In difference with cases published elsewhere the switching in
nanographite films occurs from stable high conductive to metastable low
conductive state. Critical current of switching varies in the range 10-500 mA
and can be increased up to values appropriate for using of nanographite samples
in power grids as contact-less current limiters and circuit breakers. The
possible mechanisms of switching phenomenon in nanographite films are
discussed.Comment: 4 pages, 4 figure
Three-point correlation function of a scalar mixed by an almost smooth random velocity field
We demonstrate that if the exponent that measures non-smoothness of
the velocity field is small then the isotropic zero modes of the scalar's
triple correlation function have the scaling exponents proportional to
. Therefore, zero modes are subleading with respect to the
forced solution that has normal scaling with the exponent .Comment: 13 pages, RevTeX 3.
Stable dipole solitons and soliton complexes in the nonlinear Schrodinger equation with periodically modulated nonlinearity
We develop a general classification of the infinite number of families of
solitons and soliton complexes in the one-dimensional
Gross-Pitaevskii/nonlinear Schrodinger equation with a nonlinear lattice
pseudopotential, i.e., periodically modulated coefficient in front of the cubic
term, which takes both positive and negative local values. This model finds
direct implementations in atomic Bose-Einstein condensates and nonlinear
optics. The most essential finding is the existence of two branches of dipole
solitons (DSs), which feature an antisymmetric shape, essentially squeezed into
a single cell of the nonlinear lattice. This soliton species was not previously
considered in nonlinear lattices. We demonstrate that one branch of the DS
family (namely, the one which obeys the Vakhitov-Kolokolov criterion) is
stable, while unstable DSs spontaneously transform into stable fundamental
solitons (FSs). The results are obtained in numerical and approximate
analytical forms, the latter based on the variational approximation. Some
stable bound states of FSs are found too.Comment: 12 pages, Chaos, in pres
Recovery of a quarkonium system from experimental data
For confining potentials of the form q(r)=r+p(r), where p(r) decays rapidly
and is smooth for r>0, it is proved that q(r) can be uniquely recovered from
the data {E_j,s_j}, where E_j are the bound states energies and s_j are the
values of u'_j(0), and u_j(r) are the normalized eigenfunctions of the problem
-u_j" +q(r)u_j=E_ju_j, r>0, u_j(0)=0, ||u_j||=1, where the norm is L^2(0,
\infty) norm. An algorithm is given for recovery of p(r) from few experimental
data
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