3,422 research outputs found
Non-local properties of multi-particle density matrices
As far as entanglement is concerned, two density matrices of particles
are equivalent if they are on the same orbit of the group of local unitary
transformations, (where the Hilbert space of
particle has dimension ). We show that for greater than or equal
to two, the number of independent parameters needed to specify an -particle
density matrix up to equivalence is . For
spin- particles we also show how to characterise generic
orbits, both by giving an explicit parametrisation of the orbits and by finding
a finite set of polynomial invariants which separate the orbits.Comment: 13 pages RevTe
The economic and social dimensions of Romania’s metallurgical industry
The purpose of this paper is to enhance the understanding of both the economic and social dimensions belonging to Romania’s metallurgical industry and how they contribute to generating business value. The approach of this subject became of utmost necessity in turbulent times such as the one Romania is facing nowadays
The relation productivity - environment in the context of sustainable development – case study on the Romanian industry
The purpose of this paper is to enhance the understanding of the relation between productivity and environment in the context of sustainable development, with a case study on the Romanian industry. The approach of this subject became of utmost necessity in turbulent times such as the one Romania is facing nowadays. Firstly, it provides a theoretical approach on sustainable development; secondly, it presents sustainable development as a key element in nations’ growth and thirdly, it emphasis the aspects concerning the relation productivity - environment in the context of sustainable development, with a case study on the Romanian industry
Braided Bialgebras of Type One
Braided bialgebras of type one in abelian braided monoidal categories are
characterized as braided graded bialgebras which are strongly
-graded both as an algebra and as a coalgebra
MOCVD-Fabricated TiO2 Thin Films: Influence of Growth Conditions on Fibroblast Cells Culture
TiO2 thin films with various morphologies were grown on Ti substrates by the LP-MOCVD technique (Low Pressure Chemical Vapour Deposition from Metal-Organic precursor), with titanium tetra-iso-propoxide as a precursor. All the films were prepared in the same conditions except the deposition time. They were characterized by X-ray diffraction, scanning electron microscopy, optical 15 interferometry, water contact angle measurements. MOCVD-fabricated TiO2 thin films are known to be adapted to cell culture for implant requirements. Human gingival fibroblasts were cultured on the various TiO2 deposits. Differences in cell viability (MTT tests) and cell spreading (qualitative assessment) were observed and related to film roughness, wettability and allotropic composition
Precursor films in wetting phenomena
The spontaneous spreading of non-volatile liquid droplets on solid substrates
poses a classic problem in the context of wetting phenomena. It is well known
that the spreading of a macroscopic droplet is in many cases accompanied by a
thin film of macroscopic lateral extent, the so-called precursor film, which
emanates from the three-phase contact line region and spreads ahead of the
latter with a much higher speed. Such films have been usually associated with
liquid-on-solid systems, but in the last decade similar films have been
reported to occur in solid-on-solid systems. While the situations in which the
thickness of such films is of mesoscopic size are rather well understood, an
intriguing and yet to be fully understood aspect is the spreading of
microscopic, i.e., molecularly thin films. Here we review the available
experimental observations of such films in various liquid-on-solid and
solid-on-solid systems, as well as the corresponding theoretical models and
studies aimed at understanding their formation and spreading dynamics. Recent
developments and perspectives for future research are discussed.Comment: 51 pages, 10 figures; small typos correcte
Nonsequential positive-operator-valued measurements on entangled mixed states do not always violate a Bell inequality
We present a local-hidden-variable model for positive-operator-valued
measurements (an LHVPOV model) on a class of entangled generalized Werner
states, thus demonstrating that such measurements do not always violate a
Bell-type inequality. We also show that, in general, if the state can
be obtained from with certainty by local quantum operations without
classical communication then an LHVPOV model for the state implies the
existence of such a model for .Comment: 4 pages, no figures. Title changed to accord with Phys. Rev. A
version. Journal reference adde
Implications of Teleportation for Nonlocality
Adopting an approach similar to that of Zukowski [Phys. Rev. A 62, 032101
(2000)], we investigate connections between teleportation and nonlocality. We
derive a Bell-type inequality pertaining to the teleportation scenario and show
that it is violated in the case of teleportation using a perfect singlet. We
also investigate teleportation using `Werner states' of the form x P + (1-x)
I/4, where P is the projector corresponding to a singlet state and I is the
identity. We find that our inequality is violated, implying nonlocality, if x >
1/sqrt(2). In addition, we extend Werner's local hidden variable model to
simulation of teleportation with the x = 1/2 Werner state. Thus teleportation
using this state does not involve nonlocality even though the fidelity achieved
is 3/4 which is greater than the `classical limit' of 2/3. Finally, we comment
on a result of Gisin's and offer some philosophical remarks on teleportation
and nonlocality generally.Comment: 10 pages, no figures. Title changed to accord with Phys. Rev. A
version. A note and an extra reference have been added. Journal reference
adde
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