6,224 research outputs found
Local cloning of Bell states and distillable entanglement
The necessary and sufficient amount of entanglement required for cloning of
orthogonal Bell states by local operation and classical communication is
derived, and using this result, we provide here some additional examples of
reversible, as well as irreversible states.Comment: 5 pages, two columns, Latex. Few typos have been corrected. An
explanation of the teleportation map (eqn. (3) in the manuscript) has been
provide
Palynostratigraphy and palynofacies of the early Eocene Gurha lignite mine, Rajasthan, India
A 105 m early Eocene section exposed in the Gurha mine in the Nagaur-Ganganagar Basin, Rajasthan, India, archiving remains of equatorial vegetation at a time of extreme global warmth and close to the onset of the India-Eurasia collision, is investigated using palynostratigraphic and palynofacies analyses. Four palynozones e.g., Palmidites plicatus Singh, Botryococcus braunii Kützing, Triangulorites bellus Kar and Ovoidites ligneolus are identified stratigraphically on the basis of abundance of these pollen taxa over others. The occurrence of taxonomically highly diverse angiosperm pollen in all the four palynozones attests to an extremely rich near-coastal tropical flora subject to frequent wildfires under a strongly seasonal precipitation regime. Palynotaxa characteristic of these palynozones are widely distributed in other early Paleogene sediments of India. Sedimentary organic matter (structured terrestrial, biodegraded, amorphous, grey amorphous, resins, charcoal/black-brown debris and algal remains) recovered from mire and lacustrine sediments are of terrestrial origin, recording fluctuations in burial anoxia and salinity. Episodes of elevated salinity are due either to seepage of marine waters and/or a periodic excess of evaporation over precipitation at times when the depositional system was closed
Entanglement teleportation via Bell Mixture
We investigate the teleportation of the bipartite entangled states through
two equally noisy quantum channels, namely mixture of Bell states. There is a
particular mixed state channel for which all pure entanglement in a known
Schmidt basis remain entangled after teleportation and it happens till the
channel state remains entangled. Werner state channel lacks both these
features. The relation of these noisy channels with violation of Bell's
inequality and 2-E inequality is studied.Comment: 7 pages, late
Optimal Universal Disentangling Machine for Two Qubit Quantum States
We derive the optimal curve satisfied by the reduction factors, in the case
of universal disentangling machine which uses only local operations.
Impossibility of constructing a better disentangling machine, by using
non-local operations, is discussed.Comment: 15 pages, 2 eps figures, 1 section added, 1 eps figure added, minor
corrections, 2 reference numbers correcte
Local randomness in Hardy's correlations: Implications from information causality principle
Study of nonlocal correlations in term of Hardy's argument has been quite
popular in quantum mechanics. Recently Hardy's argument of non-locality has
been studied in the context of generalized non-signaling theory as well as
theory respecting information causality. Information causality condition
significantly reduces the success probability for Hardy's argument when
compared to the result based on non-signaling condition. Here motivated by the
fact that maximally entangled state in quantum mechanics does not exhibit
Hardy's non-local correlation, we do a qualitative study of the property of
local randomness of measured observable on each side reproducing Hardy's
non-locality correlation,in the context of information causality condition. On
applying the necessary condition for respecting the principle of information
causality, we find that there are severe restrictions on the local randomness
of measured observable in contrast to results obtained from no-signaling
condition.Still, there are some restrictions imposed by quantum mechanics that
are not obtained from information causality condition.Comment: 6 pages, 2 tables, new references adde
AngularGrad: A New Optimization Technique for Angular Convergence of Convolutional Neural Networks
Convolutional neural networks (CNNs) are trained using stochastic gradient
descent (SGD)-based optimizers. Recently, the adaptive moment estimation (Adam)
optimizer has become very popular due to its adaptive momentum, which tackles
the dying gradient problem of SGD. Nevertheless, existing optimizers are still
unable to exploit the optimization curvature information efficiently. This
paper proposes a new AngularGrad optimizer that considers the behavior of the
direction/angle of consecutive gradients. This is the first attempt in the
literature to exploit the gradient angular information apart from its
magnitude. The proposed AngularGrad generates a score to control the step size
based on the gradient angular information of previous iterations. Thus, the
optimization steps become smoother as a more accurate step size of immediate
past gradients is captured through the angular information. Two variants of
AngularGrad are developed based on the use of Tangent or Cosine functions for
computing the gradient angular information. Theoretically, AngularGrad exhibits
the same regret bound as Adam for convergence purposes. Nevertheless, extensive
experiments conducted on benchmark data sets against state-of-the-art methods
reveal a superior performance of AngularGrad. The source code will be made
publicly available at: https://github.com/mhaut/AngularGrad
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