244 research outputs found
Entanglement of three-qubit pure states in terms of teleportation capability
We define an entanglement measure, called the partial tangle, which
represents the residual two-qubit entanglement of a three-qubit pure state. By
its explicit calculations for three-qubit pure states, we show that the partial
tangle is closely related to the faithfulness of a teleportation scheme over a
three-qubit pure state.Comment: 4 pages, 1 figure, accepted for publication as a Brief Report in
Physical Review
Teleportation capability, distillability, and nonlocality on three-qubit states
In this paper, we consider teleportation capability, distillability, and
nonlocality on three-qubit states. In order to investigate some relations among
them, we first find the explicit formulas of the quantities about the maximal
teleportation fidelity on three-qubit states. We show that if any three-qubit
state is useful for three-qubit teleportation then the three-qubit state is
distillable into a Greenberger-Horne-Zeilinger state, and that if any
three-qubit state violates a specific form of Mermin inequality then the
three-qubit state is useful for three-qubit teleportation.Comment: 5 pages, 2 figures; The old version has been generalized into the
results on general 3-qubit state
Concurrence of assistance and Mermin inequality on three-qubit pure states
We study a relation between the concurrence of assistance and the Mermin
inequality on three-qubit pure states. We find that if a given three-qubit pure
state has the minimal concurrence of assistance greater than 1/2 then the state
violates some Mermin inequality.Comment: 4 pages, 1 figur
Generic Bell inequalities for multipartite arbitrary dimensional systems
We present generic Bell inequalities for multipartite multi-dimensional
systems. The inequalities that any local realistic theories must obey are
violated by quantum mechanics for even-dimensional multipartite systems. A
large set of variants are shown to naturally emerge from the generic Bell
inequalities. We discuss particular variants of Bell inequalities, that are
violated for all the systems including odd-dimensional systems.Comment: Accepted in Phys. Rev. Let
Quantum states for perfectly secure secret sharing
In this work, we investigate what kinds of quantum states are feasible to
perform perfectly secure secret sharing, and present its necessary and
sufficient conditions. We also show that the states are bipartite distillable
for all bipartite splits, and hence the states could be distillable into the
Greenberger-Horne-Zeilinger state. We finally exhibit a class of secret-sharing
states, which have an arbitrarily small amount of bipartite distillable
entanglement for a certain split.Comment: 4 page
P-glycoproteins encoded by mdr 1b in murine gravid uterus and multidrug resistant tumor cell lines are differentially glycosylated
AbstractThere are 3 members of the multidrug-resitance gene family expressed in mouse. Only one of these, mdr lb, and its gene product P-glycoprotein are induced to high levels in the mouse endometrium during pregnancy. It is shown here that P-glycoprotein in the gravid uterus is significantly larger (Mr 155000) compared to P-glycoprotein encoded by mdr lb in a murine multidrug-resistant cell line (Mr 140000). However, both species co-migrate after enzymatic removal of N-linked sugars (Mr 125000). These results demonstrate that differential glycosylation of the mdr lb gene product contributes to molecular heterogeneity found in P-glycoprotein from normal and multidrug-resistant cells
Creation of NOON states by double Fock-state/Bose-Einstein condensates
NOON states (states of the form where and
are single particle states) have been used for predicting violations of
hidden-variable theories (Greenberger-Horne-Zeilinger violations) and are
valuable in metrology for precision measurements of phase at the Heisenberg
limit. We show theoretically how the use of two Fock state/Bose-Einstein
condensates as sources in a modified Mach Zender interferometer can lead to the
creation of the NOON state in which and refer to arms of the
interferometer and is the total number of particles in the two condensates.
The modification of the interferometer involves making conditional ``side''
measurements of a few particles near the sources. These measurements put the
remaining particles in a superposition of two phase states, which are converted
into NOON states by a beam splitter. The result is equivalent to the quantum
experiment in which a large molecule passes through two slits. The NOON states
are combined in a final beam splitter and show interference. Attempts to detect
through which ``slit'' the condensates passed destroys the interference.Comment: 8 pages 5 figure
Generation of Three-Qubit Entangled W-State by Nonlinear Optical State Truncation
We propose an alternative scheme to generate W state via optical state
truncation using quantum scissors. In particular, these states may be generated
through three-mode optical state truncation in a Kerr nonlinear coupler. The
more general three-qubit state may be also produced if the system is driven by
external classical fields.Comment: 7 pages, 2 figur
Quantum teleportation via a W state
We investigate two schemes of the quantum teleportation with a state,
which belongs to a different class from a Greenberger-Horne-Zeilinger class. In
the first scheme, the state is shared by three parties one of whom, called
a sender, performs a Bell measurement. It is shown that quantum information of
an unknown state is split between two parties and recovered with a certain
probability. In the second scheme, a sender takes two particles of the
state and performs positive operator valued measurements in two ways. For two
schemes, we calculate the success probability and the average fidelity. We show
that the average fidelity of the second scheme cannot exceed that of the first
one.Comment: 7 pages, 1 figur
Multipartite entanglement for entanglement teleportation
The scheme for entanglement teleportation is proposed to incorporate
multipartite entanglement of four qubits as a quantum channel. Based on the
invariance of entanglement teleportation under arbitrary two-qubit unitary
transformation, we derive relations of separabilities for joint measurements at
a sending station and for unitary operations at a receiving station. From the
relations of separabilities it is found that an inseparable quantum channel
always leads to a total teleportation of entanglement with an inseparable joint
measurement and/or a nonlocal unitary operation.Comment: slightly modifie
- …