1,832 research outputs found
Representations and Properties of Generalized Statistics
A generalization of statistics is proposed and developed. The
generalized quantum statistics is completely specified by a set of
Jacobson generators satisfying a set of triple algebraic relations.
Fock-Hilbert representations and Bargmann-Fock realizations are derived.Comment: 12 pages, to appear in IJMPA (2006
Three dimensional quantum key distribution in the presence of several eavesdroppers
Quantum key distribution based on encoding in three dimensional systems in
the presence of several eavesdroppers is proposed. This extends the BB84
protocol in the presence of many eavesdroppers where two-level quantum systems
(qubits) are replaced by three-level systems (qutrits). We discuss the
scenarios involving two, three and four complementary bases. We derive the
explicit form of Alice and Bob mutual information and the information gained by
each eavesdropper. In particular, we show that, in the presence of only one
eavesdropper, the protocol involving four bases is safer than the other ones.
However, for two eavesdroppers, the security is strongly dependent on the
attack probabilities. The effect of a large number of eavesdroppers is also
investigated
Extended Weyl-Heisenberg algebra, phase operator, unitary depolarizers and generalized Bell states
Finite dimensional representations of extended Weyl-Heisenberg algebra are
studied both from mathematical and applied viewpoints. They are used to define
unitary phase operator and the corresponding eigenstates (phase states). It is
also shown that the unitary depolarizers can be constructed in a general
setting in terms of phase operators. Generation of generalized Bell states
using the phase operator is presented and their expressions in terms of the
elements of mutually unbiased bases are given
Quantum discord in photon added Glauber coherent states of -type
We investigate the influence of photon excitations on quantum correlations in
tripartite Glauber coherent states of Greenberger-Horne-Zeilinger type. The
pairwise correlations are measured by means of the entropy-based quantum
discord. We also analyze the monogamy property of quantum discord in this class
of tripartite states in terms of the strength of Glauber coherent states and
the photon excitation order.Comment: 20 page
Pairwise quantum and classical correlations in multi-qubits states via linear relative entropy
The pairwise correlations in a multi-qubit state are quantified through a
linear variant of relative entropy. In particular, we derive the explicit
expressions of total, quantum and classical bipartite correlations. Two
different bi-partioning schemes are considered. We discuss the derivation of
closest product, quantum-classical and quantum-classical product states. We
also investigate the additivity relation between the various pairwise
correlations existing in pure and mixed states. As illustration, some special
cases are examined.Comment: 19 pages, To appear in International Journal of Quantum Informatio
Coherent and generalized intelligent states for infinite square well potential and nonlinear oscillators
This article is an illustration of the construction of coherent and
generalized intelligent states which has been recently proposed by us for an
arbitrary quantum system . We treat the quantum system submitted to the
infinite square well potential and the nonlinear oscillators. By means of the
analytical representation of the coherent states \`{a} la Gazeau-Klauder and
those \`{a} la Klauder-Perelomov, we derive the generalized intelligent states
in analytical ways
Bipartite and Tripartite Entanglement of Truncated Harmonic Oscillator Coherent States via Beam Splitters
We introduce a special class of truncated Weyl-Heisenberg algebra and discuss
the corresponding Hilbertian and analytical representations. Subsequently, we
study the effect of a quantum network of beam splitting on coherent states of
this nonlinear class of harmonic oscillators. We particularly focus on quantum
networks involving one and two beam splitters and examine the degree of
bipartite as well as tripartite entanglement using the linear entropy
Reduced Dynamics from the Unitary Group to Some Flag Manifolds : Interacting Matrix Riccati Equations
In this paper we treat the time evolution of unitary elements in the N level
system and consider the reduced dynamics from the unitary group U(N) to flag
manifolds of the second type (in our terminology). Then we derive a set of
differential equations of matrix Riccati types interacting with one another and
present an important problem on a nonlinear superposition formula that the
Riccati equation satisfies.
Our result is a natural generalization of the paper {\bf Chaturvedi et al}
(arXiv : 0706.0964 [quant-ph]).Comment: Latex ; 13 pages ; no figur
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