3,328 research outputs found
What the Bible is Really About: Decoding the Torah
Professor of Bible, Hebrew Union College-Jewish Institute of Religion, NYC; Author of The Original Torah: The Political Intent of the Bible\u27s Writers.https://digitalcommons.fairfield.edu/bennettcenter-posters/1194/thumbnail.jp
Convex ordering and quantification of quantumness
The characterization of physical systems requires a comprehensive
understanding of quantum effects. One aspect is a proper quantification of the
strength of such quantum phenomena. Here, a general convex ordering of quantum
states will be introduced which is based on the algebraic definition of
classical states. This definition resolves the ambiguity of the quantumness
quantification using topological distance measures. Classical operations on
quantum states will be considered to further generalize the ordering
prescription. Our technique can be used for a natural and unambiguous
quantification of general quantum properties whose classical reference has a
convex structure. We apply this method to typical scenarios in quantum optics
and quantum information theory to study measures which are based on the
fundamental quantum superposition principle.Comment: 9 pages, 2 figures, revised version; published in special issue "150
years of Margarita and Vladimir Man'ko
Benchmarking of Gaussian boson sampling using two-point correlators
Gaussian boson sampling is a promising scheme for demonstrating a quantum
computational advantage using photonic states that are accessible in a
laboratory and, thus, offer scalable sources of quantum light. In this
contribution, we study two-point photon-number correlation functions to gain
insight into the interference of Gaussian states in optical networks. We
investigate the characteristic features of statistical signatures which enable
us to distinguish classical from quantum interference. In contrast to the
typical implementation of boson sampling, we find additional contributions to
the correlators under study which stem from the phase dependence of Gaussian
states and which are not observable when Fock states interfere. Using the first
three moments, we formulate the tools required to experimentally observe
signatures of quantum interference of Gaussian states using two outputs only.
By considering the current architectural limitations in realistic experiments,
we further show that a statistically significant discrimination between quantum
and classical interference is possible even in the presence of loss, noise, and
a finite photon-number resolution. Therefore, we formulate and apply a
theoretical framework to benchmark the quantum features of Gaussian boson
sampling under realistic conditions
True photo-counting statistics of multiple on-off detectors
We derive a closed photo-counting formula, including noise counts and a
finite quantum efficiency, for photon number resolving detectors based on
on-off detectors. It applies to detection schemes such as array detectors and
multiplexing setups. The result renders it possible to compare the
corresponding measured counting statistics with the true photon number
statistics of arbitrary quantum states. The photo-counting formula is applied
to the discrimination of photon numbers of Fock states, squeezed states, and
odd coherent states. It is illustrated for coherent states that our formula is
indispensable for the correct interpretation of quantum effects observed with
such devices.Comment: 7 pages, 4 figure
Strongly entangled light from planar microcavities
The emission of entangled light from planar semiconductor microcavities is
studied and the entanglement properties are analyzed and quantified.
Phase-matching of the intra-cavity scattering dynamics for multiple pump beams
or pulses, together with the coupling to external radiation, leads to the
emission of a manifold of entangled photon pairs. A decomposition of the
emitted photons into two parties leads to a strong entanglement of the
resulting bipartite system. For the quantification of the entanglement, the
Schmidt number of the system is determined by the construction of Schmidt
number witnesses. It is analyzed to which extend the resources of the
originally strongly entangled light field are diminished by dephasing in
propagation channels.Comment: 9 pages, 5 figures, extended versio
Limitations for change detection in multiple Gabor targets
We investigate the limitations on the ability to detect when a target has changed, using Gabor targets as simple quantifiable stimuli. Using a partial report technique to equalise response variables, we show that the log of the Weber fraction for detecting a spatial frequency change is proportional to the log of the number of targets, with a set-size effect that is greater than that reported for visual search. This is not a simple perceptual limitation, because pre-cueing a single target out of four restores performance to the level found when only one target is present. It is argued that the primary limitation on performance is the division of attention across multiple targets, rather than decay within visual memory. However in a simplified change detection experiment without cueing, where only one target of the set changed, not only was the set size effect still larger, but it was greater at 2000 msec ISI than at 250 msec ISI, indicating a possible memory component. The steepness of the set size effects obtained suggests that even moderate complexity of a stimulus in terms of number of component objects can overload attentional processes, suggesting a possible low-level mechanism for change blindness
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