122 research outputs found
ALSEP termination report
The Apollo Lunar Surface Experiments Package (ALSEP) final report was prepared when support operations were terminated September 30, 1977, and NASA discontinued the receiving and processing of scientific data transmitted from equipment deployed on the lunar surface. The ALSEP experiments (Apollo 11 to Apollo 17) are described and pertinent operational history is given for each experiment. The ALSEP data processing and distribution are described together with an extensive discussion on archiving. Engineering closeout tests and results are given, and the status and configuration of the experiments at termination are documented. Significant science findings are summarized by selected investigators. Significant operational data and recommendations are also included
A variant of Peres-Mermin proof for testing noncontextual realist models
For any state in four-dimensional system, the quantum violation of an
inequality based on the Peres-Mermin proof for testing noncontextual realist
models has experimentally been corroborated. In the Peres-Mermin proof, an
array of nine holistic observables for two two-qubit system was used. We, in
this letter, present a new symmetric set of observables for the same system
which also provides a contradiction of quantum mechanics with noncontextual
realist models in a state-independent way. The whole argument can also be cast
in the form of a new inequality that can be empirically tested.Comment: 3 pages, To be published in Euro. Phys. Let
Parity proofs of the Bell-Kochen-Specker theorem based on the 600-cell
The set of 60 real rays in four dimensions derived from the vertices of a
600-cell is shown to possess numerous subsets of rays and bases that provide
basis-critical parity proofs of the Bell-Kochen-Specker (BKS) theorem (a
basis-critical proof is one that fails if even a single basis is deleted from
it). The proofs vary considerably in size, with the smallest having 26 rays and
13 bases and the largest 60 rays and 41 bases. There are at least 90 basic
types of proofs, with each coming in a number of geometrically distinct
varieties. The replicas of all the proofs under the symmetries of the 600-cell
yield a total of almost a hundred million parity proofs of the BKS theorem. The
proofs are all very transparent and take no more than simple counting to
verify. A few of the proofs are exhibited, both in tabular form as well as in
the form of MMP hypergraphs that assist in their visualization. A survey of the
proofs is given, simple procedures for generating some of them are described
and their applications are discussed. It is shown that all four-dimensional
parity proofs of the BKS theorem can be turned into experimental disproofs of
noncontextuality.Comment: 19 pages, 11 tables, 3 figures. Email address of first author has
been corrected. Ref.[5] has been corrected, as has an error in Fig.3.
Formatting error in Sec.4 has been corrected and the placement of tables and
figures has been improved. A new paragraph has been added to Sec.4 and
another new paragraph to the end of the Appendi
Parity proofs of the Kochen-Specker theorem based on the 24 rays of Peres
A diagrammatic representation is given of the 24 rays of Peres that makes it
easy to pick out all the 512 parity proofs of the Kochen-Specker theorem
contained in them. The origin of this representation in the four-dimensional
geometry of the rays is pointed out.Comment: 14 pages, 6 figures and 3 tables. Three references have been added.
Minor typos have been correcte
Proposed experimental tests of the Bell-Kochen-Specker theorem
For a two-particle two-state system, sets of compatible propositions exist
for which quantum mechanics and noncontextual hidden-variable theories make
conflicting predictions for every individual system whatever its quantum state.
This permits a simple all-or-nothing state-independent experimental
verification of the Bell-Kochen-Specker theorem.Comment: LaTeX, 8 page
State-independent quantum violation of noncontextuality in four dimensional space using five observables and two settings
Recently, a striking experimental demonstration [G. Kirchmair \emph{et al.},
Nature, \textbf{460}, 494(2009)] of the state-independent quantum mechanical
violation of non-contextual realist models has been reported for any two-qubit
state using suitable choices of \emph{nine} product observables and \emph{six}
different measurement setups. In this report, a considerable simplification of
such a demonstration is achieved by formulating a scheme that requires only
\emph{five} product observables and \emph{two} different measurement setups. It
is also pointed out that the relevant empirical data already available in the
experiment by Kirchmair \emph{et al.} corroborate the violation of the NCR
models in accordance with our proof
Quantum codewords contradict local realism
Quantum codewords are highly entangled combinations of two-state systems. The
standard assumptions of local realism lead to logical contradictions similar to
those found by Bell, Kochen and Specker, Greenberger, Horne and Zeilinger, and
Mermin. The new contradictions have some noteworthy features that did not
appear in the older ones.Comment: 9 pages LaTeX, 1 figur
Quantum mechanical effect of path-polarization contextuality for a single photon
Using measurements pertaining to a suitable Mach-Zehnder(MZ) type setup, a
curious quantum mechanical effect of contextuality between the path and the
polarization degrees of freedom of a polarized photon is demonstrated, without
using any notion of realism or hidden variables - an effect that holds good for
the product as well as the entangled states. This form of experimental
context-dependence is manifested in a way such that at \emph{either} of the two
exit channels of the MZ setup used, the empirically verifiable
\emph{subensemble} statistical properties obtained by an arbitrary polarization
measurement depend upon the choice of a commuting(comeasurable) path
observable, while this effect disappears for the \emph{whole ensemble} of
photons emerging from the two exit channels of the MZ setup.Comment: To be published in IJT
Kochen-Specker Vectors
We give a constructive and exhaustive definition of Kochen-Specker (KS)
vectors in a Hilbert space of any dimension as well as of all the remaining
vectors of the space. KS vectors are elements of any set of orthonormal states,
i.e., vectors in n-dim Hilbert space, H^n, n>3 to which it is impossible to
assign 1s and 0s in such a way that no two mutually orthogonal vectors from the
set are both assigned 1 and that not all mutually orthogonal vectors are
assigned 0. Our constructive definition of such KS vectors is based on
algorithms that generate MMP diagrams corresponding to blocks of orthogonal
vectors in R^n, on algorithms that single out those diagrams on which algebraic
0-1 states cannot be defined, and on algorithms that solve nonlinear equations
describing the orthogonalities of the vectors by means of statistically
polynomially complex interval analysis and self-teaching programs. The
algorithms are limited neither by the number of dimensions nor by the number of
vectors. To demonstrate the power of the algorithms, all 4-dim KS vector
systems containing up to 24 vectors were generated and described, all 3-dim
vector systems containing up to 30 vectors were scanned, and several general
properties of KS vectors were found.Comment: 19 pages, 6 figures, title changed, introduction thoroughly
rewritten, n-dim rotation of KS vectors defined, original Kochen-Specker 192
(117) vector system translated into MMP diagram notation with a new graphical
representation, results on Tkadlec's dual diagrams added, several other new
results added, journal version: to be published in J. Phys. A, 38 (2005). Web
page: http://m3k.grad.hr/pavici
Parity proofs of the Kochen-Specker theorem based on 60 complex rays in four dimensions
It is pointed out that the 60 complex rays in four dimensions associated with
a system of two qubits yield over 10^9 critical parity proofs of the
Kochen-Specker theorem. The geometrical properties of the rays are described,
an overview of the parity proofs contained in them is given, and examples of
some of the proofs are exhibited.Comment: 17 pages, 13 tables, 3 figures. Several new references have been
adde
- ā¦