1,266 research outputs found
Global Entanglement for Multipartite Quantum States
Based on the residual entanglement [9] (Phys. Rev. A \textbf{71}, 044301
(2005)), we present the global entanglement for a multipartite quantum state.
The measure is shown to be also obtained by the bipartite partitions of the
multipartite state. The distinct characteristic of the global entanglement is
that it consists of the sum of different entanglement contributions. The
measure can provide sufficient and necessary condition of fully separability
for pure states and be conveniently extended to mixed states by minimizing the
convex hull. To test the sufficiency of the measure for mixed states, we
evaluate the global entanglement of bound entangled states. The properties of
the measure discussed finally show the global entanglement is an entanglement
monotone.Comment: 6 page
Concurrence of superposition
The bounds on concurrence of the superposition state in terms of those of the
states being superposed are studied in this paper. The bounds on concurrence
are quite different from those on the entanglement measure based on von Neumann
entropy (Phys. Rev. Lett. 97, 100502 (2006)). In particular, a nonzero lower
bound can be provided if the states being superposed are properly constrained.Comment: 4 page
Climate Change Disclosure and the Promise of Response-ability and Transparency: A Synthesizing Framework and Future Research Agenda
Genuine tripartite entanglement monotone of dimensional systems
A genuine tripartite entanglement monotone is presented for -dimensional tripartite pure states by introducing a new
entanglement measure for bipartite pure states. As an application, we consider
the genuine tripartite entanglement of the ground state of the exactly solvable
isotropic spin-1/2 chain with three-spin interaction. It is shown that the
singular behavior of the genuine tripartite entanglement exactly signals a
quantum phase transition.Comment: 5 page
Graphite Nanoeraser
We present here a method for cleaning intermediate-size (5~50nm)
contamination from highly oriented pyrolytic graphite. Electron beam deposition
causes a continuous increase of carbonaceous material on graphene and graphite
surfaces, which is difficult to remove by conventional techniques. Direct
mechanical wiping using a graphite nanoeraser is observed to drastically reduce
the amount of contamination. After the mechanical removal of contamination, the
graphite surfaces were able to self-retract after shearing, indicating that van
der Waals contact bonding is restored. Since contact bonding provides an
indication of a level of cleanliness normally only attainable in a high-quality
clean-room, we discuss potential applications in preparation of ultraclean
surfaces.Comment: 10 pages, two figure
Immunopathological Roles of Cytokines, Chemokines, Signaling Molecules, and Pattern-Recognition Receptors in Systemic Lupus Erythematosus
Systemic lupus erythematosus (SLE) is an autoimmune disease with unknown etiology affecting more than one million individuals each year. It is characterized by B- and T-cell hyperactivity and by defects in the clearance of apoptotic cells and immune complexes. Understanding the complex process involved and the interaction between various cytokines, chemokines, signaling molecules, and pattern-recognition receptors (PRRs) in the immune pathways will provide valuable information on the development of novel therapeutic targets for treating SLE. In this paper, we review the immunopathological roles of novel cytokines, chemokines, signaling molecules, PRRs, and their interactions in immunoregulatory networks and suggest how their disturbances may implicate pathological conditions in SLE
Evolution of entanglement for quantum mixed states
A simple relation is introduced for concurrence to describe how much the
entanglement of bipartite system is at least left if either (or both) subsystem
undergoes an arbitrary physical process. This provides a lower bound for
concurrence of mixed states (pure states are included) in contrast to the upper
bound given by Konrad et al [Nature Physics \textbf{4}, 99 (2008)]. Our results
are also suitable for a general high dimensional bipartite quantum systems.Comment: 6 pages and 1 figur
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