Nonzero Classical Discord

Quantum discord is the quantitative difference between two alternative expressions for bipartite mutual information, given respectively in terms of two distinct definitions for the conditional entropy. By constructing a stochastic model of shared states, classical discord can be similarly defined, quantifying the presence of some stochasticity in the measurement process. Therefore, discord can generally be understood as a quantification of the system's state disturbance due to local measurements, be it quantum or classical. We establish an operational meaning of classical discord in the context of state merging with noisy measurement and thereby show the quantum-classical separation in terms of a negative conditional entropy.Comment: Replaced by the published versio

Deglaciation constraints in the Parâng Mountains, Southern Romania, using surface exposure dating

Cosmogenic nuclide surface exposure ages have been widely used to constrain glacial chronologies in the European regions. This paper brings new evidence that the Romanian Carpathians sheltered mountain glaciers in their upper valleys and cirques until the end of the last glaciation. Twenty-four 10Be surface exposure ages were obtained from boulders on moraine crests in the central area of the Parâng Mountains, Southern Carpathians. Exposure ages were used to constrain the timing of the deglaciation events during the Late Glacial. The lowest boulders yielded an age of 13.0 ± 1.1 (1766 m) and final deglaciation occurred at 10.2 ± 0.9 ka (2055 m). Timing of the Late Glacial events and complete deglaciation reported in this study are consistent with, and confirm, previously reported ages of deglaciation within the Carpathian and surrounding European region

The Socialization of Primary School Pupils through Motor Games

This paper aims to bring to the forefront the most important connecting element of society, namely socialization. Improving socialization through motor games is, perhaps, a solution to many problems, as children align emotionally, emotionally, volitionally, physically, cognitively, etc. The study was conducted on a sample of 59 students aged 6 to 9 years. The sociometric technique was used to determine negative, positive, and neutral interpersonal relationships by age level before and after the use of the chosen motor games. The index of preferred status, cohesion index, arithmetic mean and progress rate were used for statistical interpretation

Dielectric Behavior of Nonspherical Cell Suspensions

Recent experiments revealed that the dielectric dispersion spectrum of fission yeast cells in a suspension was mainly composed of two sub-dispersions. The low-frequency sub-dispersion depended on the cell length, whereas the high-frequency one was independent of it. The cell shape effect was qualitatively simulated by an ellipsoidal cell model. However, the comparison between theory and experiment was far from being satisfactory. In an attempt to close up the gap between theory and experiment, we considered the more realistic cells of spherocylinders, i.e., circular cylinders with two hemispherical caps at both ends. We have formulated a Green function formalism for calculating the spectral representation of cells of finite length. The Green function can be reduced because of the azimuthal symmetry of the cell. This simplification enables us to calculate the dispersion spectrum and hence access the effect of cell structure on the dielectric behavior of cell suspensions.Comment: Preliminary results have been reported in the 2001 March Meeting of the American Physical Society. Accepted for publications in J. Phys.: Condens. Matte

On the robustness of bucket brigade quantum RAM

We study the robustness of the bucket brigade quantum random access memory model introduced by Giovannetti, Lloyd, and Maccone [Phys. Rev. Lett. 100, 160501 (2008)]. Due to a result of Regev and Schiff [ICALP '08 pp. 773], we show that for a class of error models the error rate per gate in the bucket brigade quantum memory has to be of order $o(2^{-n/2})$ (where $N=2^n$ is the size of the memory) whenever the memory is used as an oracle for the quantum searching problem. We conjecture that this is the case for any realistic error model that will be encountered in practice, and that for algorithms with super-polynomially many oracle queries the error rate must be super-polynomially small, which further motivates the need for quantum error correction. By contrast, for algorithms such as matrix inversion [Phys. Rev. Lett. 103, 150502 (2009)] or quantum machine learning [Phys. Rev. Lett. 113, 130503 (2014)] that only require a polynomial number of queries, the error rate only needs to be polynomially small and quantum error correction may not be required. We introduce a circuit model for the quantum bucket brigade architecture and argue that quantum error correction for the circuit causes the quantum bucket brigade architecture to lose its primary advantage of a small number of "active" gates, since all components have to be actively error corrected.Comment: Replaced with the published version. 13 pages, 9 figure

Topology of amorphous tetrahedral semiconductors on intermediate lengthscales

Using the recently-proposed ``activation-relaxation technique'' for optimizing complex structures, we develop a structural model appropriate to a-GaAs which is almost free of odd-membered rings, i.e., wrong bonds, and possesses an almost perfect coordination of four. The model is found to be superior to structures obtained from much more computer-intensive tight-binding or quantum molecular-dynamics simulations. For the elemental system a-Si, where wrong bonds do not exist, the cost in elastic energy for removing odd-membered rings is such that the traditional continuous-random network is appropriate. Our study thus provides, for the first time, direct information on the nature of intermediate-range topology in amorphous tetrahedral semiconductors.Comment: 4 pages, Latex and 2 postscript figure

Hold Your Methods! How Multineuronal Firing Ensembles Can Be Studied Using Classical Spike-Train Analysis Techniques

Responses of neuronal populations play an important role in the encoding of stimulus related information. However, the inherent multidimensionality required to describe population activity has imposed significant challenges and has limited the applicability of classical spike train analysis techniques. Here, we show that these limitations can be overcome. We first quantify the collective activity of neurons as multidimensional vectors (patterns). Then we characterize the behavior of these patterns by applying classical spike train analysis techniques: peri-stimulus time histograms, tuning curves and auto- and cross-correlation histograms. We find that patterns can exhibit a broad spectrum of properties, some resembling and others substantially differing from those of their component neurons. We show that in some cases pattern behavior cannot be intuitively inferred from the activity of component neurons. Importantly, silent neurons play a critical role in shaping pattern expression. By correlating pattern timing with local-field potentials, we show that the method can reveal fine temporal coordination of cortical circuits at the mesoscale. Because of its simplicity and reliance on well understood classical analysis methods the proposed approach is valuable for the study of neuronal population dynamics

Distributed normal faulting in the tip zone of the South Alkyonides Fault System, Gulf of Corinth, constrained using 36Cl exposure dating of late-Quaternary wave-cut platforms

The geometry, rates and kinematics of active faulting in the region close to the tip of a major crustal-scale normal fault in the Gulf of Corinth, Greece, are investigated using detailed fault mapping and new absolute dating. Fault offsets have been dated using a combination of 234U/230Th coral dates and in situ 36Cl cosmogenic exposure ages for sediments and wave-cut platforms deformed by the faults. Our results show that deformation in the tip zone is distributed across as many as eight faults arranged within ~700 m across strike, each of which deforms deposits and landforms associated with the 125 ka marine terrace of Marine Isotope Stage 5e. Summed throw-rates across strike achieve values as high as 0.3–1.6 mm/yr, values that are comparable to those at the centre of the crustal-scale fault (2–3 mm/yr from Holocene palaeoseismology and 3–4 mm/yr from GPS geodesy). The relatively high deformation rate and distributed deformation in the tip zone are discussed in terms of stress enhancement from rupture of neighbouring crustal-scale faults and in terms of how this should be considered during fault-based seismic hazard assessment