510 research outputs found
Playing a quantum game with a corrupted source
The quantum advantage arising in a simplified multi-player quantum game, is
found to be a disadvantage when the game's qubit-source is corrupted by a noisy
"demon". Above a critical value of the corruption-rate, or noise-level, the
coherent quantum effects impede the players to such an extent that the optimal
choice of game changes from quantum to classical.Comment: This version will appear in PRA (Rapid Comm.
Quantum games of asymmetric information
We investigate quantum games in which the information is asymmetrically
distributed among the players, and find the possibility of the quantum game
outperforming its classical counterpart depends strongly on not only the
entanglement, but also the informational asymmetry. What is more interesting,
when the information distribution is asymmetric, the contradictive impact of
the quantum entanglement on the profits is observed, which is not reported in
quantum games of symmetric information.Comment: 5 pages, 3 figure
Hopping Transport in the Presence of Site Energy Disorder: Temperature and Concentration Scaling of Conductivity Spectra
Recent measurements on ion conducting glasses have revealed that conductivity
spectra for various temperatures and ionic concentrations can be superimposed
onto a common master curve by an appropriate rescaling of the conductivity and
frequency. In order to understand the origin of the observed scaling behavior,
we investigate by Monte Carlo simulations the diffusion of particles in a
lattice with site energy disorder for a wide range of both temperatures and
concentrations. While the model can account for the changes in ionic activation
energies upon changing the concentration, it in general yields conductivity
spectra that exhibit no scaling behavior. However, for typical concentrations
and sufficiently low temperatures, a fairly good data collapse is obtained
analogous to that found in experiment.Comment: 6 pages, 4 figure
BEW: Bioinformatics workbench for analysis of biofilms experimental data
Biofilms research has evolved considerably in the last decade and is now generating large volumes of heterogeneous data. MIABiE, the international initiative on Biofilms, is devising guidelines for data interchange, and some databases provide access to biofilms experiments. However, the field is lacking appropriate bioinformatics tools in support of increasing operational and analytical needs. This paper presents a flexible and extensible open-source workbench for the operation and analysis of biofilms experiments, as follows: (i) the creation of customised experiments, (ii) the collection of various analytical results, following community standardisation guidelines and (iii) on-demand reporting and statistical evaluation
Correlated electrons in the presence of disorder
Several new aspects of the subtle interplay between electronic correlations
and disorder are reviewed. First, the dynamical mean-field theory
(DMFT)together with the geometrically averaged ("typical") local density of
states is employed to compute the ground state phase diagram of the
Anderson-Hubbard model at half-filling. This non-perturbative approach is
sensitive to Anderson localization on the one-particle level and hence can
detect correlated metallic, Mott insulating and Anderson insulating phases and
can also describe the competition between Anderson localization and
antiferromagnetism. Second, we investigate the effect of binary alloy disorder
on ferromagnetism in materials with -electrons described by the periodic
Anderson model. A drastic enhancement of the Curie temperature caused by
an increase of the local -moments in the presence of disordered conduction
electrons is discovered and explained.Comment: 17 pages, 7 figures, final version, typos corrected, references
updated, submitted to Eur. Phys. J. for publication in the Special Topics
volume "Cooperative Phenomena in Solids: Metal-Insulator Transitions and
Ordering of Microscopic Degrees of Freedom
Quantum version of the Monty Hall problem
©2002 The American Physical SocietyA version of the Monty Hall problem is presented where the players are permitted to select quantum strategies. If the initial state involves no entanglement the Nash equilibrium in the quantum game offers the players nothing more than that obtained with a classical mixed strategy. However, if the initial state involves entanglement of the qutrits of the two players, it is advantageous for one player to have access to a quantum strategy while the other does not. Where both players have access to quantum strategies there is no Nash equilibrium in pure strategies, however, there is a Nash equilibrium in quantum mixed strategies that gives the same average payoff as the classical game.A. P. Flitney and D. Abbot
Simulation for training in sinus floor elevation : new surgical bench model
Objectives: to describe a bench model (workshop of abilities) for sinus floor elevation (SFE) training that simulates the surgical environment and to assess its effectiveness in terms of trainees? perception. Study design: thirty-six randomly selected postgraduate students entered this cross-sectional pilot study and asked to fill in an anonymous, self-applied, 12-item questionnaire about a SFE workshop that included a study guide containing the workshop?s details, supervised practice on a simulated surgical environment, and assessment by means of specific check-lists. Results: Thirtiy-six fresh sheep heads were prepared to allow access to the buccal vestible. Using the facial tuber, third premolar and a 3D-CT study as landmarks for trepanation, the sinus membrane was lifted, the space filled with ceramic material and closed with a resorbable membrane. The participants agreed on their ability to perform SFE in a simulated situation (median score= 4.5; range 2-5) and felt capable to teach the technique to other clinicians or to undertake the procedure for a patient under supervision of an expert surgeon (median= 4; range 1-5 ). There were no differences on their perceived ability to undertake the technique on a model or on a real patient under supervision of an expert surgeon (p=0.36). Conclusions: Clinical abilities workshops for SFE teaching are an essential educational tool but supervised clinical practice should always precede autonomous SFE on real patients. Simulation procedures (workshop of abilities) are perceived by the partakers as useful for the surgical practice. However, more studies are needed to validate the procedure and to address cognitive and communication skills, that are clearly integral parts of surgical performance
Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC
Measurements of inclusive jet suppression in heavy ion collisions at the LHC
provide direct sensitivity to the physics of jet quenching. In a sample of
lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated
luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with
a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the
transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the
anti-kt algorithm with values for the distance parameter that determines the
nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of
the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp.
Jet production is found to be suppressed by approximately a factor of two in
the 10% most central collisions relative to peripheral collisions. Rcp varies
smoothly with centrality as characterized by the number of participating
nucleons. The observed suppression is only weakly dependent on jet radius and
transverse momentum. These results provide the first direct measurement of
inclusive jet suppression in heavy ion collisions and complement previous
measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables,
submitted to Physics Letters B. All figures including auxiliary figures are
available at
http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
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