545 research outputs found
Comment on "Quantum Teleportation of Eight-Qubit State via Six-Qubit Cluster State"
Recently, Zhao et al., (Int. J. Theor. Phys. 57, 516-522 (2018)) have
proposed a scheme for quantum teleportation of an eight-qubit quantum state
using a six qubit cluster state. In this comment, it's shown that the quantum
resource (multi-partite entangled state used as the quantum channel) used by
Zhao et al., is excessively high and the task can be performed using any two
Bell states as the task can be reduced to the teleportation of an arbitrary two
qubit state. Further, a trivial conceptual mistake made by Zhao et al., in the
description of the quantum channel has been pointed out. It's also mentioned
that recently a trend of proposing teleportation schemes with excessively high
quantum resources has been observed and the essence of this comment is
applicable to all such proposals.Comment: It is shown that teleportation of multi qubit-states can be done
using Bell state
Quantum Zeno and anti-Zeno effects in an asymmetric nonlinear optical coupler
Quantum Zeno and anti-Zeno effects in an asymmetric nonlinear optical coupler
are studied. The asymmetric nonlinear optical coupler is composed of a linear
waveguide () and a nonlinear waveguide
() interacting with each other through the evanescent
waves. The nonlinear waveguide has quadratic nonlinearity and it operates under
second harmonic generation. A completely quantum mechanical description is used
to describe the system. The closed form analytic solutions of Heisenberg's
equations of motion for the different field modes are obtained using Sen-Mandal
perturbative approach. In the coupler, the linear waveguide acts as a probe on
the system (nonlinear waveguide). The effect of the presence of the probe
(linear waveguide) on the photon statistics of the second harmonic mode of the
system is considered as quantum Zeno and anti-Zeno effects. Further,it is also
shown that in the stimulated case, it is easy to switch between quantum Zeno
and anti-Zeno effects just by controlling the phase of the second harmonic mode
of the asymmetric couplerComment: 7 pages. This work was presented in the International Conference on
Optics and Photonics 2015,Kolkata, Indi
Hierarchical quantum communication
A general approach to study the hierarchical quantum information splitting
(HQIS) is proposed and the same is used to systematically investigate the
possibility of realizing HQIS using different classes of 4-qubit entangled
states that are not connected by SLOCC. Explicit examples of HQIS using 4-qubit
cluster state and 4-qubit |\Omega> state are provided. Further, the proposed
HQIS scheme is generalized to introduce two new aspects of hierarchical quantum
communication. To be precise, schemes of probabilistic hierarchical quantum
information splitting and hierarchical quantum secret sharing are obtained by
modifying the proposed HQIS scheme. A number of practical situations where
hierarchical quantum communication would be of use are also presented.Comment: 14 pages, 6 tables, no figur
Wigner distribution, nonclassicality and decoherence of generalized and reciprocal binomial states
There are quantum states of light that can be expressed as finite
superpositions of Fock states (FSFS). We demonstrate the nonclassicality of an
arbitrary FSFS by means of its phase space distributions such as the Wigner
function and the -function. The decoherence of the FSFS is studied by
considering the time evolution of its Wigner function in amplitude decay and
phase damping channels. As examples, we determine the nonclassicality and
decoherence of generalized and reciprocal binomial states.Comment: 18 pages, 8 Figure
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