18,009 research outputs found
Superactivation of monogamy relations for nonadditive quantum correlation measures
We investigate the general monogamy and polygamy relations satisfied by
quantum correlation measures. We show that there exist two real numbers
and such that for any quantum correlation measure ,
is monogamous if and polygamous if for a
given multipartite state . For , we show that the
monogamy relation can be superactivated by finite copies
of for nonadditive correlation measures. As a detailed example, we use
the negativity as the quantum correlation measure to illustrate such
superactivation of monogamy properties. A tighter monogamy relation is
presented at last
Monogamy relations of all quantum correlation measures for multipartite quantum systems
The monogamy relations of quantum correlation restrict the sharability of
quantum correlations in multipartite quantum states. We show that all measures
of quantum correlations satisfy some kind of monogamy relations for arbitrary
multipartite quantum states. Moreover, by introducing residual quantum
correlations, we present tighter monogamy inequalities that are better than all
the existing ones. In particular, for multi-qubit pure states, we also
establish new monogamous relations based on the concurrence and concurrence of
assistance under the partition of the first two qubits and the remaining ones.Comment: arXiv admin note: text overlap with arXiv:1206.4029 by other author
Pion Production in Heavy-ion Collisions in the 1 A GeV region
Within the framework of the improved isospin dependent quantum molecular
dynamics (ImIQMD) model, the pion emission in heavy-ion collisions in the
region 1 A GeV is investigated systematically, in which the pion is considered
to be mainly produced by the decay of resonances (1232) and
N*(1440). The in-medium dependence and Coulomb effects of the pion production
are included in the calculation. Total pion multiplicity and
yields are calculated for the reaction Au+Au in central
collisions for selected Skyrme parameters SkP, SLy6, Ska, SIII and compared
them with the measured data by the FOPI collaboration.Comment: 9 pages, 5 figure
Polygamy relations of multipartite entanglement beyond qubits
We investigate the polygamy relations related to the concurrence of
assistance for any multipartite pure states. General polygamy inequalities
given by the th power of concurrence of
assistance is first presented for multipartite pure states in
arbitrary-dimensional quantum systems. We further show that the general
polygamy inequalities can even be improved to be tighter inequalities under
certain conditions on the assisted entanglement of bipartite subsystems. Based
on the improved polygamy relations, lower bound for distribution of bipartite
entanglement is provided in a multipartite system. Moreover, the th
() power of polygamy inequalities are obtained for the
entanglement of assistance as a by-product, which are shown to be tighter than
the existing ones. A detailed example is presented.Comment: arXiv admin note: text overlap with arXiv:1902.0744
Quantifying quantum coherence and non-classical correlation based on Hellinger distance
Quantum coherence and non-classical correlation are key features of quantum
world. Quantifying coherence and non-classical correlation are two key tasks in
quantum information theory. First, we present a bona fide measure of quantum
coherence by utilizing the Hellinger distance. This coherence measure is proven
to fulfill all the criteria of a well defined coherence measure, including the
strong monotonicity in the resource theories of quantum coherence. In terms of
this coherence measure, the distribution of quantum coherence in multipartite
systems is studied and a corresponding polygamy relation is proposed. Its
operational meanings and the relations between the generation of quantum
correlations and the coherence are also investigated. Moreover, we present
Hellinger distance-based measure of non-classical correlation, which not only
inherits the nice properties of the Hellinger distance including contractivity,
and but also shows a powerful analytic computability for a large class of
quantum states. We show that there is an explicit trade-off relation satisfied
by the quantum coherence and this non-classical correlation
Fusion dynamics of symmetric systems near barrier energies
The enhancement of the sub-barrier fusion cross sections was explained as the
lowering of the dynamical fusion barriers within the framework of the improved
isospin-dependent quantum molecular dynamics (ImIQMD) model. The numbers of
nucleon transfer in the neck region are appreciably dependent on the incident
energies, but strongly on the reaction systems. A comparison of the neck
dynamics is performed for the symmetric reactions Ni+Ni and
Ni+Ni at energies in the vicinity of the Coulomb barrier. An
increase of the ratios of neutron to proton in the neck region at initial
collision stage is observed and obvious for neutron-rich systems, which can
reduce the interaction potential of two colliding nuclei. The distribution of
the dynamical fusion barriers and the fusion excitation functions are
calculated and compared them with the available experimental data.Comment: 9 pages, 5 figure
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