Positivity in the presence of initial system-environment correlation

The constraints imposed by the initial system-environment correlation can lead to nonpositive Dynamical maps. We find the conditions for positivity and complete positivity of such dynamical maps by using the concept of an assignment map. Any initial system-environment correlations make the assignment map nonpositive, while the positivity of the dynamical map depends on the interplay between the assignment map and the system-environment coupling. We show how this interplay can reveal or hide the nonpositivity of the assignment map. We discuss the role of this interplay in Markovian models.Comment: close to the published version. 5 pages, 1 figur

Foundations of Quantum Discord

This paper summarizes the basics of the notion of quantum discord and how it relates to other types of correlations in quantum physics. We take the fundamental information theoretic approach and illustrate our exposition with a number of simple examples.Comment: 3 pages, special issue edited by Diogo de Oliveira Soares Pinto et a

Quantum Correlations in Multipartite Quantum Systems

We review some concepts and properties of quantum correlations, in particular multipartite measures, geometric measures and monogamy relations. We also discuss the relation between classical and total correlationsComment: to be published as a chapter of the book "Lectures on general quantum correlations and their applications" edited by F. Fanchini, D. Soares-Pinto, and G. Adesso (Springer, 2017

Characterization of Macerals in Coal Fines using Image Analysis Technique

Coal is an aggregate of heterogeneous substance consisting of various or aiiic cemsti-tnents so called nuacerals along with inorganic matter. These inacerals have been broadly classified into three major maceral groups i.e. vitrinite, exinite (liptinite) and inertinite. Coal-fines of size less than 0.5 mm, collected from Moonidih coal washery, was used in the present stud. These coal fines were subjected to size analysis and sink-float analysis. The products obtained at different size and density fractions were mounted in resin + hardener mixture using standard sample preparation technique and polished- The polished samples were examined tender- microscope inte-rfaced with image analyzer: Results indicate that size and density fractions have a significant influence on the changes in the maceral concentrations. The same has been discussed in terms of physical coal cleaning, process

Diabetes in pregnancy and infant adiposity: systematic review and meta-analysis

Objective: Maternal glycaemia and anthropometry-derived newborn adiposity are strongly correlated. The children of mothers with diabetes are at greater risk of adverse metabolic health, and increased adiposity is a plausible mediator. We undertook a systematic review and meta-analysis to compare adiposity in infants of mothers with (IDM) and without diabetes (NIDM). Design: We identified observational studies reporting adiposity in IDM and NIDM. We searched references, traced forward citations and contacted authors for additional data. We considered all body composition techniques and compared fat mass, fat-free mass, body fat % and skinfold thickness. We used random effects meta-analyses and performed subgroup analyses by maternal diabetes type (type 1, type 2, gestational) and infant sex. We examined the influence of pre-pregnancy BMI and conducted sensitivity analyses. Results: We included data from 35 papers and over 24,000 infants. IDM have greater fat mass than NIDM (mean difference [95% CI]); 83g [49, 117]. Fat mass is greater in infants of mothers with gestational diabetes; 62g [29, 94] and type 1 diabetes; 268g [139, 397]. Insufficient studies reported data for type 2 diabetes separately. Compared with NIDM, fat mass was greater in IDM boys; 87g [30, 145], but not significantly different in IDM girls; 42g [- 33, 116]. There was no attenuation after adjustment for maternal BMI. Conclusions: IDM have significantly greater adiposity in comparison to NIDM. These findings are justification for studies to determine whether measures to reduce infant adiposity will improve later health

Palladium(II) saccharinate complexes trans-[Pd(sac)(2)(LH)(2)] with amino- and acetylamino-pyridine co-ligands: molecular structures of trans-[PdCl2(2-ampyH)(2)].2dmf (2-ampyH=2-amino-3-methylpyridine) and trans-[Pd(kappa(2)-2-acmpy)(2)] (2-acmpyH=2-acetylamino-3-methylpyridine)

Reaction of Na2[PdCl4] with two equivalents of amino- or acetylamino-pyridines (LH) affords trans-[PdCl2-(LH)2] {LH = 2-amino-3-methylpyridine (2-ampyH), 3-aminopyridine (3-apyH), 2-acetylamino-3-methylpyridine (2-acmpyH), 3-acetylamino-pyridine (3-acpyH)}. An X-ray crystal structure of trans-[PdCl2(2-ampyH)2] shows that the 2-ampy-H ligands are coordinated in a monodentate fashion via the nitrogen atoms of the pyridine rings. Treatment of trans-[PdCl2(2-acmpyH)2] with NEt3 affords the cyclometalated complex, trans-[Pd(κ2-2-acmpy)2], the X-ray structure of which shows that the 2-acmpy ligand is coordinated to palladium in a bidentate fashion via the nitrogen atom of the pyridine ring and oxygen. Reaction of trans-[PdCl2(LH)2] with two equivalents of sodium saccharinate affords the bis(saccharinate) complexes, trans-[Pd(sac)2(LH)2], in which the saccharinate anions are coordinated via the amide nitrogen atom

Dissipative dynamics of quantum discord under quantum chaotic environment

We investigate the dissipative dynamics of quantum discord in a decoherence model with two initially entangled qubits in addition to a quantum kicked top. The two qubits are uncoupled during the period of our study and one of them interacts with the quantum kicked top. We find that the long time behavior of quantum discord could be well described by the fidelity decay of the quantum kicked top; for short time behavior, however, the phase of the amplitude of the fidelity decay is necessary to provide more specific information about the system. We have made comparison between the quantum kicked top and multi-mode oscillator system in describing environment, and also compared the dynamics of the entanglement with that of quantum discord.Comment: 5 pages, 3 figures, and Accepted by Europhysics Letter

Unification of Witnessing Initial System-Environment Correlations and Witnessing Non-Markovianity

We show the connection between a witness that detects dynamical maps with initial system-environment correlations and a witness that detects non-Markovian open quantum systems. Our analysis is based on studying the role that state preparation plays in witnessing violations of contractivity of open-quantum-system dynamics. Contractivity is a property of some quantum processes where the trace distance of density matrices decrease with time. From this, we show how a witness of initial correlations is an upper bound to a witness of non-Markovianity. We discuss how this relationship shows further connections between initial system-environment correlations and non-Markovianity, at an instance of time, in open quantum systems.Chemistry and Chemical Biolog