1,557 research outputs found
Tighter weighted polygamy inequalities of multipartite entanglement in arbitrary-dimensional quantum systems
We investigate polygamy relations of multipartite entanglement in
arbitrary-dimensional quantum systems. By improving an inequality and using the
th () power of entanglement of assistance, we provide a
new class of weighted polygamy inequalities of multipartite entanglement in
arbitrary-dimensional quantum systems. We show that these new polygamy
relations are tighter than the ones given in [Phys. Rev. A 97, 042332 (2018)]
Ordering states with various coherence measures
Quantum coherence is one of the most significant theories in quantum physics.
Ordering states with various coherence measures is an intriguing task in
quantification theory of coherence. In this paper, we study this problem by use
of four important coherence measures -- the norm of coherence, the
relative entropy of coherence, the geometric measure of coherence and the
modified trace distance measure of coherence. We show that each pair of these
measures give a different ordering of qudit states when . However, for
single-qubit states, the norm of coherence and the geometric coherence
provide the same ordering. We also show that the relative entropy of coherence
and the geometric coherence give a different ordering for single-qubit states.
Then we partially answer the open question proposed in [Quantum Inf. Process.
15, 4189 (2016)] whether all the coherence measures give a different ordering
of states.Comment: 12 page
A search for 95 GHz class I methanol masers in molecular outflows
We have observed a sample of 288 molecular outflow sources including 123
high-mass and 165 low-mass sources to search for class I methanol masers at 95
GHz transition and to investigate relationship between outflow characteristics
and class I methanol maser emission with the PMO-13.7m radio telescope. Our
survey detected 62 sources with 95 GHz methanol masers above 3
detection limit, which include 47 high-mass sources and 15 low-mass sources.
Therefore the detection rate is 38% for high-mass outflow sources and 9% for
low-mass outflow sources, suggesting that class I methanol maser is relatively
easily excited in high-mass sources. There are 37 newly detected 95 GHz
methanol masers (including 27 high-mass and 10 low-mass sources), 19 of which
are newly identified (i.e. first identification) class I methanol masers
(including 13 high-mass and 6 low-mass sources). Statistical analysis for the
distributions of maser detections with the outflow parameters reveals that the
maser detection efficiency increases with outflow properties (e.g. mass,
momentum, kinetic energy and mechanical luminosity of outflows etc.).
Systematic investigations of relationships between the intrinsic luminosity of
methanol maser and the outflow properties (including mass, momentum, kinetic
energy, bolometric luminosity and mass loss rate of central stellar sources)
indicate a positive correlations. This further supports that class I methanol
masers are collisionally pumped and associated with shocks, where outflows
interact with the surrounding ambient medium.Comment: 32 pages, 5 figures, accepted by Ap
Amending coherence-breaking channels via unitary operations
The coherence-breaking channels play a significant role in quantum
information theory. We study the coherence-breaking channels and give a method
to amend the coherence-breaking channels by applying unitary operations. For
given incoherent channel , we give necessary and sufficient conditions
for the channel to be a coherence-breaking channel and amend it via unitary
operations. For qubit incoherent channels that are not
coherence-breaking ones, we consider the mapping and present
the conditions for coherence-breaking and channel amendment as well.Comment: 8 page
A Survey Study on Consumer Perception of Mobile- Commerce Applications
AbstractMobile commerce (m-commerce) can have an important influence on business and society in the future. Hence, m- commerce developers and practitioners must understand consumers’ perception of m-commerce applications in order to better design and deliver m-commerce service. This paper studied Chinese consumers’ perception of m-commerce applications by using the survey methodology. Firstly, 44 mobile applications were adopted on the basis of related study work, and then the web-based questionnaire was employed for obtaining online Chinese consumers’ importance ratings with regard to each mobile application. The survey result is helpful for both academics and practitioners to better design innovative and satisfying m-commerce applications
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