583 research outputs found
A complementary relation between classical bits and randomness in local part in simulating singlet state
Recently Leggett's proposal of non-local model generates new interest in
simulating the statistics of singlet state. Singlet state statistics can be
simulated by 1 bit of classical communication without using any further
nonlocal correlation. But, interestingly, singlet state statistics can also be
simulated with no classical cost if a non-local box is used. In the first case,
the output is completely unbiased whereas in second case outputs are completely
random. We suggest a new (possibly) signaling correlation resource which
successfully simulates singlet statistics and this result suggests a new
complementary relation between required classical bits and randomness in local
output when the classical communication is limited by 1 cbit. This result
reproduces the above two models of simulation as extreme cases. This also
explains why Leggett's non-local model and the model presented by Branciard
et.al. should fail to reproduce the statistics of a singlet.Comment: v3: Typos corrected, few changed notations, some extensions to
earlier write-u
Degree of Complementarity Determines the Nonlocality in Quantum Mechanics
Complementarity principle is one of the central concepts in quantum mechanics
which restricts joint measurement for certain observables. Of course, later
development shows that joint measurement could be possible for such observables
with the introduction of a certain degree of unsharpness or fuzziness in the
measurement. In this paper, we show that the optimal degree of unsharpness,
which guarantees the joint measurement of all possible pairs of dichotomic
observables, determines the degree of nonlocality in quantum mechanics as well
as in more general no-signaling theories.Comment: Close to published versio
Local simulation of singlet statistics for restricted set of measurement
The essence of Bell's theorem is that, in general, quantum statistics cannot
be reproduced by local hidden variable (LHV) model. This impossibility is
strongly manifested while analyzing the singlet state statistics for Bell-CHSH
violations. In this work, we provide various subsets of two outcome POVMs for
which a local hidden variable model can be constructed for singlet state.Comment: 2 column, 5 pages, 4 figures, new references, abstract modified,
accepted in JP
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
Vertical distributions of the microscopic morphological characteristics and elemental composition of aerosols over India
Particle morphology and elemental compositions are among the crucial parameters of aerosols required for accurate understanding of the climatic effect of aerosols in the earth-atmosphere system; yet their vertical distributions and region specific properties are poorly characterised due to sparse in-situ measurements. This is the first study to classify and quantify the vertical distributions of the morphological characteristics and elemental composition of aerosols based on single particle as well as bulk chemical analysis over seven geographically diverse regions of northern and central parts of India during spring (April-May, 2013), carried out as a part of Regional Aerosol Warming Experiment (RAWEX). Significant regional distinctiveness in shapes (non-sphericity), sizes and elemental compositions of the airborne particles were conspicuous, having dominance of highly irregular granular aggregates over the north Indian sites. The non-spherical coarse mode particles dominated the lower free tropospheric regions (> 2 km) of the Indo-Gangetic Plains (IGP). These particles could be responsible for enhanced spring time aerosol absorption in the elevated region of the atmosphere. Elemental compositions of the single particle analysis indicate that the free tropospheric layer over the IGP and central India is enriched with Na and Ca compounds mixed with Fe or Al (soil particles), indicating long range transport of crustal aerosols. This finding is very well supported by the bulk particle analysis indicating abundance of Ca(2+)in the free troposphere with low contribution of ssNa(+). Particles with irregular rough surfaces having dominance of SiO(2)were observed over all the study sites. The percentage share of spherical (either smooth or rough) particles to the total morphological characteristics of the particles was found to be highly subdued (<10%). The present study thus critically assesses the relevant knowledge pertaining to the morphological features of aerosols over the IGP during spring for the accurate estimation of aerosol radiative properties. More such efforts are required in future to study the connections and dependencies between morphological and radiative properties of aerosols in different seasons.Peer reviewe
Partners in School: An Innovative Parent-Teacher Consultation Model for Children with Autism Spectrum Disorder
Little research examines the best ways to improve communication between parents and teachers of children with Autism Spectrum Disorder (ASD) and its effect on child outcomes. The present study tests an innovative parent-teacher consultation model, entitled Partners in School. The goal of Partners in School is to improve parent-teacher communication aboutevidence-based practices (EBPs), and subsequently, outcomes for children with ASD. Participants were 26 teachers and 49 parents of children with ASD from a large urban public school district. Parents and teachers completed measures of their communication and child outcomes prior to and after receiving consultation through Partners in School. Results indicated that parents and teachers perceived improvements in child outcomes after participation inPartners in School. Changes in parent- teacher communication also were associated with changes in some child outcomes. Discussionhighlights the important role of communication inconsultations targeting family-school partnerships for children with ASD
Classical communication and non-classical fidelity of quantum teleportation
In quantum teleportation, the role of entanglement has been much discussed.
It is known that entanglement is necessary for achieving non-classical
teleportation fidelity. Here we focus on the amount of classical communication
that is necessary to obtain non-classical fidelity in teleportation. We
quantify the amount of classical communication that is sufficient for achieving
non-classical fidelity for two independent 1-bit and single 2-bits noisy
classical channels. It is shown that on average 0.208 bits of classical
communication is sufficient to get non-classical fidelity. We also find the
necessary amount of classical communication in case of isotropic
transformation. Finally we study how the amount of sufficient classical
communication increases with weakening of entanglement used in the
teleportation process.Comment: Accepted in Quantum Info. Proces
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