11,849 research outputs found
Multi-Photon Interference and Temporal Distinguishability of Photons
A number of recent interference experiments involving multiple photons are
reviewed. These experiments include generalized photon bunching effects,
generalized Hong-Ou-Mandel interference effects and multi-photon interferometry
for demonstrations of multi-photon de Broglie wavelength. The multi-photon
states used in these experiments are from two pairs of photons in parametric
down-conversion. We find that the size of the interference effect in these
experiments, characterized by the visibility of interference pattern, is
governed by the degree of distinguishability among different pairs of photons.
Based on this discovery, we generalize the concept of multi-photon temporal
distinguishability and relate it to a number of multi-photon interference
effects. Finally, we make an attempt to interpret the coherence theory by the
multi-photon interference via the concept of temporal distinguishability of
photons.Comment: fixed figures 4,5,
Violation of monogamy inequality for higher-dimensional objects
Bipartite quantum entanglement for qutrits and higher-dimensional objects is
considered. We analyze the possibility of violation of monogamy inequality,
introduced by Coffman, Kundu, and Wootters, for some systems composed of such
objects. An explicit counterexample with a three-qutrit totally antisymmetric
state is presented. Since three-tangle has been confirmed to be a natural
measure of entanglement for qubit systems, our result shows that the
three-tangle is no longer a legitimate measure of entanglement for states with
three qutrits or higher dimensional objects.Comment: 2.5 pages,minor modifications are mad
Visualization of Big Spatial Data using Coresets for Kernel Density Estimates
The size of large, geo-located datasets has reached scales where
visualization of all data points is inefficient. Random sampling is a method to
reduce the size of a dataset, yet it can introduce unwanted errors. We describe
a method for subsampling of spatial data suitable for creating kernel density
estimates from very large data and demonstrate that it results in less error
than random sampling. We also introduce a method to ensure that thresholding of
low values based on sampled data does not omit any regions above the desired
threshold when working with sampled data. We demonstrate the effectiveness of
our approach using both, artificial and real-world large geospatial datasets
Colour Design for Carton-Packed Fruit Juice Packages
The present research studies the relationships between observersā expectations for 7 fruit juice packages and the colour design of the package. To do this, a two-stage experiment was conducted. At the first stage, we studied perceived colours for the fruit images shown on each package. At the second stage, fruit juice packages with 20 package colours were rated using 5 bipolar scales: colour harmony, preference, freshness, naturalness and product quality. The experimental results show that the observers tended to perceive fruit image colours lighter and more saturated than those measured using colour measuring instruments. Using factor analyses, we classified the 5 bipolar scales into 2 factors: Product Preference and Freshness. Package colour design was found to have significant impacts on both factors: similarity in chroma and hue between package colour and perceived fruit colour would lead to high product expectations.
Keywords:
colour design; colour harmony; product expectation; perceived image colour</p
Entanglement and Superdense Coding with Linear Optics
We discuss a scheme for a full superdense coding of entangled photon states
employing only linear-optics elements. By using the mixed basis consisting of
four states that are unambiguously distinguishable by a standard and polarizing
beam splitters we can deterministically transfer four messages by manipulating
just one of the two entangled photons. The sender achieves the determinism of
the transfer either by giving up the control over 50% of sent messages
(although known to her) or by discarding 33% of incoming photons.Comment: 8 pages, 1 figur
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