26 research outputs found
Local Quantum Uncertainty in Two-Qubit Separable States: A Case Study
Recent findings suggest, separable states, which are otherwise of no use in
entanglement dependent tasks, can also be used in information processing tasks
that depend upon the discord type general non classical correlations. In this
work, we explore the nature of uncertainty in separable states as measured by
local quantum uncertainty. Particularly in two-qubit system, we find separable
X-state which has maximum local quantum uncertainty. Interestingly, this
separable state coincides with the separable state, having maximum geometric
discord. We also search for the maximum amount of local quantum uncertainty in
separable Bell diagonal states. We indicate an interesting connection to the
tightness of entropic uncertainty with the state of maximum uncertainty.Comment: 11 pages, 2 figures, latex2e, comments welcome, to appear in qi
On Strong Monogamy Conjecture in Four-Qubit System
Monogamy is a defining feature of entanglement, having far reaching
applications. Recently, Regula \textit{et.al.} in Phys. Rev. Lett.
\textbf{113}, 110501(2014) have proposed a stronger version of monogamy
relation for concurrence. We have extended the strong monogamy inequality for
another entanglement measure, viz., negativity. In particular, we have
concentrated on four-qubit system and provided a detail study on the status of
strong monogamy on pure states. Further, we have analytically provided some
classes of states for which negativity and squared negativity satisfy strong
monogamy. Numerical evidences have also been shown in proper places. Our
analysis also provides cases where strong monogamy is violated.Comment: 8 pages, 8 figures, revtex, comments welcom
Decoherence Dynamics of Measurement-Induced Nonlocality and comparison with Geometric Discord for two qubit systems
We check the decoherence dynamics of Measurement-induced Nonlocality(in
short, MIN) and compare it with geometric discord for two qubit systems. There
are quantum states, on which the action of dephasing channel cannot destroy MIN
in finite or infinite time. We check the additive dynamics of MIN on a qubit
state under two independent noise. Geometric discord also follows such additive
dynamics like quantum discord. We have further compared non-Markovian evolution
of MIN and geometric discord under dephasing and amplitude damping noise for
pure state and it shows distinct differences between their dynamics.Comment: 11 pages, 10 figures, Revte
Character of superposed states under deterministic LOCC
In this paper we investigate the effect of superposition of states on local
conversion of pure bipartite states under deterministic LOCC. We are able to
form a bridge between comparable and incomparable classes of states through the
linear superposition of states. For example, if we consider two pairs of
incomparable states, then their superposition may result into a comparable pair
of states. We investigate many such cases and provide some of the results in
tabular form. We also investigate the entanglement behavior of such classes of
states, specifically their monotone nature. Finally we provide some bounds of
different measures of entanglement based on the idea of comparability and
incomparability under deterministic LOCC.Comment: 9 pages, pdflatex, no figure, to appear in the journal Quantum
Information Processin
3-D numerical study of the effect of Reynolds number and baffle angle on heat transfer and pressure drop of turbulent flow of air through rectangular duct of very small height
SummaryPresent article illustrates a computational study of three-dimensional steady state heat transfer and high turbulent flow characteristics through a rectangular duct with constant heat fluxed upper wall and single rectangular cross-sectioned baffle insertion at different angles. RNG k–ɛ model along with standard wall function based computations has been accomplished applying the finite volume method, and SIMPLE algorithm has been executed for solving the governing equations. For a Reynolds number, Re of 10,000 to 50,000, Prandtl Number, Pr of 0.707 and baffle angle, α of 30°, 60°, 90°, 120°, 150°, computational studies are executed, centred onto the hydraulic diameter, Dh, test section and hydrodynamic entry length of the duct. Flow field has been solved using Ansys Fluent 14.0 software. Study exposes that baffled rectangular duct has a higher average Nusselt number, Nu and Darcy friction factor, f compared to a smooth rectangular duct. Nu as well as f are found to be maximum at 90° baffle angle. Results illustrate that both α and Re play a significant role in heat transfer as well as flow characteristics and also effects TEF. The correctness of the results attained in this study is corroborated by comparing the results with those existing in the literature for smooth rectangular duct within a precision of ±2% for f and ±4% for Nu