18 research outputs found
Coherent states for Hamiltonians generated by supersymmetry
Coherent states are derived for one-dimensional systems generated by
supersymmetry from an initial Hamiltonian with a purely discrete spectrum for
which the levels depend analytically on their subindex. It is shown that the
algebra of the initial system is inherited by its SUSY partners in the subspace
associated to the isospectral part or the spectrum. The technique is applied to
the harmonic oscillator, infinite well and trigonometric Poeschl-Teller
potentials.Comment: LaTeX file, 26 pages, 3 eps figure
Dobinski-type relations and the Log-normal distribution
We consider sequences of generalized Bell numbers B(n), n=0,1,... for which
there exist Dobinski-type summation formulas; that is, where B(n) is
represented as an infinite sum over k of terms P(k)^n/D(k). These include the
standard Bell numbers and their generalizations appearing in the normal
ordering of powers of boson monomials, as well as variants of the "ordered"
Bell numbers. For any such B we demonstrate that every positive integral power
of B(m(n)), where m(n) is a quadratic function of n with positive integral
coefficients, is the n-th moment of a positive function on the positive real
axis, given by a weighted infinite sum of log-normal distributions.Comment: 7 pages, 2 Figure
Extended Bell and Stirling numbers from hypergeometric exponentiation
Exponentiating the hypergeometric series
0FL(1,1,...,1;z), L = 0,1,2,..., furnishes a recursion relation for the members of certain integer sequences
bL(n), n = 0,1,2,.... For L >= 0, the bL(n)'s are generalizations of the conventional Bell numbers, b0(n). The corresponding associated Stirling numbers of the second kind are also investigated. For L = 1 one can give a combinatorial interpretation of the numbers b1(n) and of some Stirling numbers associated with them. We also consider the L>1 analogues of Bell numbers for restricted partitions
Generalized boson algebra and its entangled bipartite coherent states
Starting with a given generalized boson algebra U_(h(1)) known as the
bosonized version of the quantum super-Hopf U_q[osp(1/2)] algebra, we employ
the Hopf duality arguments to provide the dually conjugate function algebra
Fun_(H(1)). Both the Hopf algebras being finitely generated, we produce a
closed form expression of the universal T matrix that caps the duality and
generalizes the familiar exponential map relating a Lie algebra with its
corresponding group. Subsequently, using an inverse Mellin transform approach,
the coherent states of single-node systems subject to the U_(h(1)) symmetry
are found to be complete with a positive-definite integration measure.
Nonclassical coalgebraic structure of the U_(h(1)) algebra is found to
generate naturally entangled coherent states in bipartite composite systems.Comment: 15pages, no figur
Coherent states associated to the wavefunctions and the spectrum of the isotonic oscillator
Classes of coherent states are presented by replacing the labeling parameter
of Klauder-Perelomov type coherent states by confluent hypergeometric
functions with specific parameters. Temporally stable coherent states for the
isotonic oscillator Hamiltonian are presented and these states are identified
as a particular case of the so-called Mittag-Leffler coherent states.Comment: 12 page
Temporally stable coherent states in energy degenerate systems: The hydrogen atom
Klauder's recent generalization of the harmonic oscillator coherent states
[J. Phys. A 29, L293 (1996)] is applicable only in non-degenerate systems,
requiring some additional structure if applied to systems with degeneracies.
The author suggests how this structure could be added, and applies the complete
method to the hydrogen atom problem. To illustrate how a certain degree of
freedom in the construction may be exercised, states are constructed which are
initially localized and evolve semi-classically, and whose long time evolution
exhibits "fractional revivals."Comment: 9 pages, 3 figure
New q-deformed coherent states with an explicitly known resolution of unity
We construct a new family of q-deformed coherent states , where . These states are normalizable on the whole complex plane and continuous
in their label . They allow the resolution of unity in the form of an
ordinary integral with a positive weight function obtained through the analytic
solution of the associated Stieltjes power-moment problem and expressed in
terms of one of the two Jacksons's -exponentials. They also permit exact
evaluation of matrix elements of physically-relevant operators. We use this to
show that the photon number statistics for the states is sub-Poissonian and
that they exhibit quadrature squeezing as well as an enhanced signal-to-quantum
noise ratio over the conventional coherent state value. Finally, we establish
that they are the eigenstates of some deformed boson annihilation operator and
study some of their characteristics in deformed quantum optics.Comment: LaTeX, 26 pages, contains 9 eps figure
Shape invariant potential formalism for photon-added coherent state construction
An algebro-operator approach, called shape invariant potential method, of
constructing generalized coherent states for photon-added particle system is
presented. Illustration is given on Poschl-Teller potential
Creating quanta with "annihilation" operator
An asymmetric nature of the boson `destruction' operator and its
`creation' partner is made apparent by applying them to a
quantum state different from the Fock state . We show that it is
possible to {\em increase} (by many times or by any quantity) the mean number
of quanta in the new `photon-subtracted' state . Moreover, for
certain `hyper-Poissonian' states the mean number of quanta in the
(normalized) state can be much greater than in the
`photon-added' state . The explanation of this
`paradox' is given and some examples elucidating the meaning of Mandel's
-parameter and the exponential phase operators are considered.Comment: 10 pages, LaTex, an extended version with several references added
and the text divided into sections; to appear in J. Phys.
Multi-dimensional trio coherent states
We introduce a novel class of higher-order, three-mode states called
K-dimensional trio coherent states. We study their mathematical properties and
prove that they form a complete set in a truncated Fock space. We also study
their physical content by explicitly showing that they exhibit nonclassical
features such as oscillatory number distribution, sub-poissonian statistics,
Cauchy-Schwarz inequality violation and phase-space quantum interferences.
Finally, we propose an experimental scheme to realize the state with K=2 in the
quantized vibronic motion of a trapped ion.Comment: 17 pages, 12 figures, accepted for publication in J. Phys. A: Math.
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