3,539 research outputs found
The NDT Program at Stanford University
Some of the things that are going on at Stanford include my own, Shaw\u27s, Auld\u27s and Quate\u27s work. In particular, one of the things that was mentioned this morning, which I think is very exciting, is Shaw\u27s work on PVF2 plastic transducers. He is obtaining very broad bandwidths of the order of 10 MHz with absolutely flat responses. These are very impressive transducers, and I think they are going to be very important in the future
Regularized Green's Function for the Inverse Square Potential
A Green's function approach is presented for the D-dimensional inverse square
potential in quantum mechanics. This approach is implemented by the
introduction of hyperspherical coordinates and the use of a real-space
regulator in the regularized version of the model. The application of
Sturm-Liouville theory yields a closed expression for the radial energy Green's
function. Finally, the equivalence with a recent path-integral treatment of the
same problem is explicitly shown.Comment: 10 pages. The final section was expande
Optimized pulse sequences for suppressing unwanted transitions in quantum systems
We investigate the nature of the pulse sequence so that unwanted transitions
in quantum systems can be inhibited optimally. For this purpose we show that
the sequence of pulses proposed by Uhrig [Phys. Rev. Lett. \textbf{98}, 100504
(2007)] in the context of inhibition of environmental dephasing effects is
optimal. We derive exact results for inhibiting the transitions and confirm the
results numerically. We posit a very significant improvement by usage of the
Uhrig sequence over an equidistant sequence in decoupling a quantum system from
unwanted transitions. The physics of inhibition is the destructive interference
between transition amplitudes before and after each pulse.Comment: 5 figure
Huge automatically extracted training sets for multilingual Word Sense Disambiguation
We release to the community six large-scale sense-annotated datasets in multiple language to pave the way for supervised multilingual Word Sense Disambiguation. Our datasets cover all the nouns in the English WordNet and their translations in other languages for a total of millions of sense-tagged sentences. Experiments prove that these corpora can be effectively used as training sets for supervised WSD systems, surpassing the state of the art for low- resourced languages and providing competitive results for English, where manually annotated training sets are accessible. The data is available at trainomatic. org
Strong violations of Bell-type inequalities for Werner-like states
We investigate the violation of Bell-type inequalities for two-qubit
Werner-like states parametrized by the positive parameter 0<p<1. We use an
unbalanced homodyne detection scheme to obtain the quantum mechanical
probabilities. A violation of the Bell-Wigner and Janssens inequalities is
obtained for a large range of the parameter p. The range given by these
inequalities is greater than the one given by the Clauser-Horne inequality. The
range in which a violation is attained actually coincides with the range where
the Werner-like states are known to be nonseparabel, i.e., for p>1/3. However,
the improvement over the Clauser-Horne inequality is achieved at the price of
restricting the class of possible local hidden variable theories.Comment: Revised manuscript, accepted for publication in PR
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