1,504 research outputs found
Non-classical properties and algebraic characteristics of negative binomial states in quantized radiation fields
We study the nonclassical properties and algebraic characteristics of the
negative binomial states introduced by Barnett recently. The ladder operator
formalism and displacement operator formalism of the negative binomial states
are found and the algebra involved turns out to be the SU(1,1) Lie algebra via
the generalized Holstein-Primarkoff realization. These states are essentially
Peremolov's SU(1,1) coherent states. We reveal their connection with the
geometric states and find that they are excited geometric states. As
intermediate states, they interpolate between the number states and geometric
states. We also point out that they can be recognized as the nonlinear coherent
states. Their nonclassical properties, such as sub-Poissonian distribution and
squeezing effect are discussed. The quasiprobability distributions in phase
space, namely the Q and Wigner functions, are studied in detail. We also
propose two methods of generation of the negative binomial states.Comment: 17 pages, 5 figures, Accepted in EPJ
Entangled SU(2) and SU(1,1) coherent states
Entangled SU(2) and SU(1,1) coherent states are developed as superpositions
of multiparticle SU(2) and SU(1,1) coherent states. In certain cases, these are
coherent states with respect to generalized su(2) and su(1,1) generators, and
multiparticle parity states arise as a special case. As a special example of
entangled SU(2) coherent states, entangled binomial states are introduced and
these entangled binomial states enable the contraction from entangled SU(2)
coherent states to entangled harmonic oscillator coherent states. Entangled
SU(2) coherent states are discussed in the context of pairs of qubits. We also
introduce the entangled negative binomial states and entangled squeezed states
as examples of entangled SU(1,1) coherent states. A method for generating the
entangled SU(2) and SU(1,1) coherent states is discussed and degrees of
entanglement calculated. Two types of SU(1,1) coherent states are discussed in
each case: Perelomov coherent states and Barut-Girardello coherent states.Comment: 31 pages, no figure
Delay-dependent stability of linear multi-step methods for linear neutral systems
summary:In this paper, we are concerned with numerical methods for linear neutral systems with multiple delays. For delay-dependently stable neutral systems, we ask what conditions must be imposed on linear multi-step methods in order that the numerical solutions display stability property analogous to that displayed by the exact solutions. Combining with Lagrange interpolation, linear multi-step methods can be applied to the neutral systems. Utilizing the argument principle, a sufficient condition is derived for linear multi-step methods with preserving delay-dependent stability. Numerical examples are given to illustrate the main results
Quantum correlation measure in arbitrary bipartite systems
A definition of quantum correlation is presented for an arbitrary bipartite
quantum state based on the skew information. This definition not only inherits
the good properties of skew information such as the contractivity and so on,
but also is effective and almost analytically calculated for any bipartite
quantum states. We also reveal the relation between our measure and quantum
metrology. As applications, we give the exact expressions of quantum
correlation for many states, which provides a direct support for our result.Comment: 6 pages, 2 figures. Comments are welcom
Small interfering RNA mediated multi-target therapy of cancer
Abstract: It has been reviewed that as many as hundreds genes are dysregulated in various kinds of cancers, yet most therapies are targeted toward a single gene. Recently, the mode of cancer treatment has been changed by a shift in thinking from mono-target to multi-target therapies. There is considerable evidence that these have a higher possibility of success than mono-target therapy, and multi-target therapy should remain the most attractive avenue for future treatment strategies. In this article, we attempt to provide evidence for the role of small interfering RNA in multi-target therapy of cancer
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