39,895 research outputs found
Dissociation energy and long-range potential of diatomic molecules from vibrational spacings - The halogens
Dissociation energy and long-range potential of diatomic molecules from vibrational spacings, halogen
Shape resonances and rotationally predissociating levels - The atomic collision time delay functions and quasibound level properties of H2 /Chi /1 Sigma g plus//
Atomic collision time delay functions and quasibound level properties of ground state of molecular hydroge
Position Dependent Mass Schroedinger Equation and Isospectral Potentials : Intertwining Operator approach
Here we have studied first and second-order intertwining approach to generate
isospectral partner potentials of position-dependent (effective) mass
Schroedinger equation. The second-order intertwiner is constructed directly by
taking it as second order linear differential operator with position depndent
coefficients and the system of equations arising from the intertwining
relationship is solved for the coefficients by taking an ansatz. A complete
scheme for obtaining general solution is obtained which is valid for any
arbitrary potential and mass function. The proposed technique allows us to
generate isospectral potentials with the following spectral modifications: (i)
to add new bound state(s), (ii) to remove bound state(s) and (iii) to leave the
spectrum unaffected. To explain our findings with the help of an illustration,
we have used point canonical transformation (PCT) to obtain the general
solution of the position dependent mass Schrodinger equation corresponding to a
potential and mass function. It is shown that our results are consistent with
the formulation of type A N-fold supersymmetry [14,18] for the particular case
N = 1 and N = 2 respectively.Comment: Some references have been adde
Phase properties of a new nonlinear coherent state
We study phase properties of a displacement operator type nonlinear coherent
state. In particular we evaluate the Pegg-Barnett phase distribution and
compare it with phase distributions associated with the Husimi Q function and
the Wigner function. We also study number- phase squeezing of this state.Comment: 8 eps figures. to appear in J.Opt
The Effect of Using Multiple Intelligence Strategy on Students\u27 Achievement in Writing Narrative Texts
This study was conducted to find out the effect of using multiple intelligence strategy on students\u27 achievement in writing narrative texts. The population was the students of grade XI SMA SWASTA KATOLIK 2 Kabanjahe. There were 142 students and 60 of them were taken as the sample based on random sampling technique. Thirty students were taken as control group and others as experimental group (taught by using MI strategy). The instrument used to collect the data was a written test. The data were analyzed by using t-test to show the effect of MI Strategy on students\u27 achievement in writing narrative text. The results of the analysis showed that t-value 2.73 was higher than t-table 1.67 at the level of significance 0.05 and the degree of freedom (df) 58. It means that the alternative hypothesis is accepted. In other words, it is obvious that MI Strategy can cause significant effect on students\u27 achievement in writing narrative text
Phases, many-body entropy measures and coherence of interacting bosons in optical lattices
Already a few bosons with contact interparticle interactions in small optical
lattices feature a variety of quantum phases: superfluid, Mott-insulator and
fermionized Tonks gases can be probed in such systems. To detect these phases
-- pivotal for both experiment and theory -- as well as their many-body
properties we analyze several distinct measures for the one-body and many-body
Shannon information entropies. We exemplify the connection of these entropies
with spatial correlations in the many-body state by contrasting them to the
Glauber normalized correlation functions. To obtain the ground-state for
lattices with commensurate filling (i.e. an integer number of particles per
site) for the full range of repulsive interparticle interactions we utilize the
multiconfigurational time-dependent Hartree method for bosons (MCTDHB) in order
to solve the many-boson Schr\"odinger equation. We demonstrate that all
emergent phases -- the superfluid, the Mott insulator, and the fermionized gas
can be characterized equivalently by our many-body entropy measures and by
Glauber's normalized correlation functions. In contrast to our many-body
entropy measures, single-particle entropy cannot capture these transitions.Comment: 11 pages, 7 figures, software available at http://ultracold.or
Information-theoretic significance of the Wigner distribution
A coarse grained Wigner distribution p_{W}(x,u) obeying positivity derives
out of information-theoretic considerations. Let p(x,u) be the unknown joint
PDF (probability density function) on position- and momentum fluctuations x,u
for a pure state particle. Suppose that the phase part Psi(x,z) of its Fourier
transform F.T.[p(x,u)]=|Z(x,z)|exp[iPsi(x,z)] is constructed as a hologram.
(Such a hologram is often used in heterodyne interferometry.) Consider a
particle randomly illuminating this phase hologram. Let its two position
coordinates be measured. Require that the measurements contain an extreme
amount of Fisher information about true position, through variation of the
phase function Psi(x,z). The extremum solution gives an output PDF p(x,u) that
is the convolution of the Wigner p_{W}(x,u) with an instrument function
defining uncertainty in either position x or momentum u. The convolution arises
naturally out of the approach, and is one-dimensional, in comparison with the
two-dimensional convolutions usually proposed for coarse graining purposes. The
output obeys positivity, as required of a PDF, if the one-dimensional
instrument function is sufficiently wide. The result holds for a large class of
systems: those whose amplitudes a(x) are the same at their boundaries
(Examples: states a(x) with positive parity; with periodic boundary conditions;
free particle trapped in a box).Comment: pdf version has 16 pages. No figures. Accepted for publ. in PR
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