1,950 research outputs found
A feasible quantum optical experiment capable of refuting noncontextuality for single photons
Elaborating on a previous work by Simon et al. [PRL 85, 1783 (2000)] we
propose a realizable quantum optical single-photon experiment using standard
present day technology, capable of discriminating maximally between the
predictions of quantum mechanics (QM) and noncontextual hidden variable
theories (NCHV). Quantum mechanics predicts a gross violation (up to a factor
of 2) of the noncontextual Bell-like inequality associated with the proposed
experiment. An actual maximal violation of this inequality would demonstrate
(modulo fair sampling) an all-or-nothing type contradiction between QM and
NCHV.Comment: LaTeX file, 8 pages, 1 figur
Bell's theorem without inequalities and without alignments
A proof of Bell's theorem without inequalities is presented which exhibits
three remarkable properties: (a) reduced local states are immune to collective
decoherence; (b) distant local setups do not need to be aligned, since the
required perfect correlations are achieved for any local rotation of the local
setups; (c) local measurements require only individual measurements on the
qubits. Indeed, it is shown that this proof is essentially the only one which
fulfils (a), (b), and (c).Comment: REVTeX4, 4 page
Dicke-like quantum phase transition and vacuum entanglement with two coupled atomic ensembles
We study the coherent cooperative phenomena of the system composed of two
interacting atomic ensembles in the thermodynamic limit. Remarkably, the system
exhibits the Dicke-like quantum phase transition and entanglement behavior
although the governing Hamiltonian is fundamentally different from the
spin-boson Dicke Hamiltonian, offering the opportunity for investigating
collective matter-light dynamics with pure matter waves. The model can be
realized with two Bose-Einstein condensates or atomic ensembles trapped in two
optical cavities coupled to each other. The interaction between the two
separate samples is induced by virtual photon exchange
Stronger two-observer all-versus-nothing violation of local realism
We introduce a two-observer all-versus-nothing proof of Bell's theorem which
reduces the number of required quantum predictions from 9 [A. Cabello, Phys.
Rev. Lett. 87, 010403 (2001); Z.-B. Chen et al., Phys. Rev. Lett. 90, 160408
(2003)] to 4, provides a greater amount of evidence against local realism,
reduces the detection efficiency requirements for a conclusive experimental
test of Bell's theorem, and leads to a Bell's inequality which resembles
Mermin's inequality for three observers [N. D. Mermin, Phys. Rev. Lett. 65,
1838 (1990)] but requires only two observers.Comment: REVTeX4, 5 page
The Wheel of Engagement: Exploring the Connection Between the Brand/Target Relationship, Brain Physiology, Human Psychology and the Laws of Marketing in an Ever-Changing World.
What happens when the sciences of brain physiology, human psychology and marketing collide with the science of creativity? Could this generate a massive impact leading to the Holy Grail of marketing—a rare insight into the code for building strong brand/customer relationships? As a veteran copywriter and creative director in the ad industry, my tools for gaining customer insight were limited to traditional research and strategy methodologies such as focus groups, interviews and surveys, and to my gut instincts. Once introduced to the science of creativity, I became curious about certain connections to human behavior—specifically connections between the physiology of the brain and the contributions of Abraham Maslow and Carl Jung to human psychology. These connections point to a controlling part of the human unconscious where the Point of Emotional Impact resides between a brand and its customer. This paper takes you on an expedition to that Point of Emotional Impact showing you how elements of Maslow’s Hierarchy of Needs and Jung’s archetypes intersect in the limbic system forming an indelible bond between a brand and its customer. Along the way, you will discover a model to describe this phenomenon and creativity tools to help uncover the right information needed to engage the model. This then, is a personal journey into learning and connecting, as well as a quest to give to my marketing communications agency a badge of distinction and calling card for new business
You-Just-Can’t-Win Dept.: Firm Sues Workers for Failing to Strike, circa 1999
Newspaper article about an Ohio nursing home that hired replacement workers in anticipation of a strike, then sued the Service Employees International Union because the union didn’t go on strike. The Wall Street Journal. Youngstown, Ohio
Multisetting Bell-type inequalities for detecting genuine tripartite entanglement
In a recent paper, Bancal et al. put forward the concept of
device-independent witnesses of genuine multipartite entanglement. These
witnesses are capable of verifying genuine multipartite entanglement produced
in a lab without resorting to any knowledge of the dimension of the state space
or of the specific form of the measurement operators. As a by-product they
found a three-party three-setting Bell inequality which enables to detect
genuine tripartite entanglement in a noisy 3-qubit Greenberger-Horne-Zeilinger
(GHZ) state for visibilities as low as 2/3 in a device-independent way. In this
paper, we generalize this inequality to an arbitrary number of settings,
demonstrating a threshold visibility of 2/pi~0.6366 for number of settings
going to infinity. We also present a pseudo-telepathy Bell inequality achieving
the same threshold value. We argue that our device-independent witnesses are
optimal in the sense that the above value cannot be beaten with
three-party-correlation Bell inequalities.Comment: 7 page
Nested entangled states for distributed quantum channels
We find a coupling-strength configuration for a linear chain of N spins which
gives rise to simultaneous multiple Bell states. We suggest a way such an
interesting entanglement pattern can be used in order to distribute maximally
entangled channels to remote locations and generate multipartite entanglement
with a minimum-control approach. Our proposal thus provides a way to achieve
the core resources in distributed information processing. The schemes we
describe can be efficiently tested in chains of coupled cavities interacting
with three-level atoms.Comment: 4 pages, 2 figures, RevTeX
On the logical structure of Bell theorems without inequalities
Bell theorems show how to experimentally falsify local realism. Conclusive
falsification is highly desirable as it would provide support for the most
profoundly counterintuitive feature of quantum theory - nonlocality. Despite
the preponderance of evidence for quantum mechanics, practical limits on
detector efficiency and the difficulty of coordinating space-like separated
measurements have provided loopholes for a classical worldview; these loopholes
have never been simultaneously closed. A number of new experiments have
recently been proposed to close both loopholes at once. We show some of these
novel designs fail in the most basic way, by not ruling out local hidden
variable models, and we provide an explicit classical model to demonstrate
this. They share a common flaw, which reveals a basic misunderstanding of how
nonlocality proofs work. Given the time and resources now being devoted to such
experiments, theoretical clarity is essential. Our explanation is presented in
terms of simple logic and should serve to correct misconceptions and avoid
future mistakes. We also show a nonlocality proof involving four participants
which has interesting theoretical properties.Comment: 8 pages, text clarified, explicit LHV model provided for flawed
nonlocality tes
Nonlocality without inequality for spin-s system
We analyze Hardy's non-locality argument for two spin-s systems and show that
earlier solution in this regard was restricted due to imposition of some
conditions which have no role in the argument of non-locality. We provide a
compact form of non-locality condition for two spin-s systems and extend it to
n number of spin-s particles. We also apply more general kind of non-locality
argument still without inequality, to higher spin system.Comment: 6 page
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