Information transfer using a single particle path-spin hybrid entangled state

The path-spin entangled state of a single spin-1/2 particle is considered which is generated by using a beam-spitter and a spin-flipper. Using this hybrid entanglement at the level of a single particle as a resource, we formulate a protocol for transferring of the state of an unknown qubit to a distant location. Our scheme is implemented by a sequence of unitary operations along with suitable spin-measurements, as well as by using classical communication between the two spatially separated parties. This protocol, thus, demonstrates the possibility of using intraparticle entanglement as a physical resource for performing information theoretic tasks.     

A simple expression for the ADM mass

We show by an almost elementary calculation that the ADM mass of an asymptotically flat space can be computed as a limit involving a rate of change of area of a closed 2-surface. The result is essentially the same as that given by David Brown and York (Phys. Rev. D 55, 1977–1984 1997; Phys. Rev. D 47, 1407–1419 1993). We will prove this result in two ways, first by direct calculation from the original formula as given by Arnowitt, Deser and Misner and second as a corollary of an earlier result by Brewin for the case of simplicial spaces.     

Stochastic resonance in a monostable system driven by square-wave signal and dichotomous noise

<正>This paper investigates the stochastic resonance in a monostable system driven by square-wave signal,asymmetric dichotomous noise as well as by multiplicative and additive white noise.By the use of the properties of the dichotomous noise,it obtains the expressions of the signal-to-noise ratio under the adiabatic approximation condition.It finds that the signal-to-noise ratio is a non-monotonic function of the asymmetry of the dichotomous noise,and which varies non-monotonously with the intensity of the multiplicative and additive noise as well as the system parameters.Moreover, the signal-to-noise ratio depends on the correlation rate and intensity of the dichotomous noise.     

A three-dimensional coupled-mode model for the acoustic field in a two-dimensional waveguide with perfectly reflecting boundaries

This paper presents a three-dimensional(3D) coupled-mode model using the direct-global-matrix technique as well as Fourier synthesis. This model is a full wave, two-way three-dimensional model, and is therefore capable of providing accurate acoustic field solutions. Because the problem of sound propagation excited by a point source in an ideal wedge with perfectly reflecting boundaries is one of a few three-dimensional problems with analytical solutions, the ideal wedge problem is chosen in this work to validate the presented three-dimensional model. Numerical results show that the field results by analytical solutions and those by the presented model are in excellent agreement, indicating that the presented model can serve as a benchmark model for three-dimensional sound propagation problems involving a planar two-dimensional geometry as well as a point source.     

The interaction of outgoing echolocation pulses and echoes in the false killer whale's auditory system: evoked-potential study

Brain auditory evoked potentials (AEP) associated with echolocation were recorded in a false killer whale Pseudorca crassidens trained to accept suction-cup EEG electrodes and to detect targets by echolocation. AEP collection was triggered by echolocation pulses transmitted by the animal. The target was a hollow aluminum cylinder of strength of -22 dB at a distance from 1 to 8 m. Each AEP record was obtained by averaging more than 1000 individual records. All the records contained two AEP sets: the first one of a constant latency and a second one with a delay proportional to the distance. The timing of these two AEP sets was interpreted as responses to the transmitted echolocation pulse and echo, respectively. The echo-related AEP, although slightly smaller, was comparable to the outgoing click-related AEP in amplitude, even though at a target distance as far as 8 m the echo intensity was as low as -64 dB relative to the transmitted pulse in front of the head. The amplitude of the echo-related AEP was almost independent of distance, even though variation of target distance from 1 to 8 m influenced the echo intensity by as much as 36 dB.     

Probing the validity of average Hamiltonian theory for spin I=1, 3/2 and 5/2 nuclei by analyzing a simple two-pulse sequence

In this work, we investigate the accuracy of controlling spin I=1, 3/2 and 5/2 spin systems by average Hamiltonian theory. By way of example, we consider a simple two-pulse echo sequence and compare this perturbation scheme to a numerical solution of the Von Neumann equation. For the different values of I, we examine this precision as a function of the quadrupolar coupling as well as various experimental parameters such as the pulse spacing and pulse width. Experiments and simulations on I=3/2 and I=5/2 spin systems are presented that highlight a spectral artifact introduced due to finite pulse widths as predicted by average Hamiltonian theory. The control of these spin systems by this perturbation scheme is considered by investigating a phase cycling scheme that suppresses these artifacts to zeroth-order of the Magnus expansion.     

Black Holes Are One-Dimensional

The holographic principle has revealed that phyical systems in 3-D space, black holes included, are basically two-dimensional as far as their information content is concerned. This conclusion is complemented by one sketched here: as far as entropy or information flow is concerned, a black hole behaves as a one-dimensional channel. We define a channel in flat spacetime in thermodynamic terms, and contrast it with common entropy emitting systems. A black hole is more like the former: its entropy output is related to the emitted power as it would be for a one-dimensional channel, and disposal of an information stream down a black hole is limited by the power invested in the same way as for a one-dimensional channel.     

A cylindrical liquid-core waveguide

A novel concept for a liquid-core lightguide in cylindrical symmetry is presented. For a concrete 17 cm long device using water as a core and the transparent fluorinated polymer Teflon as a cladding layer, the coupling efficiency and guiding properties are investigated theoretically and compared with experimental results. The guide is found to exhibit low losses. A possible application of this type of guide is investigated by replacing the optical cell of a standard UV/VIS spectrometer by the cylindrical liquid-core waveguide. An increasing sensitivity for especially low concentrations of a polluting dye by a factor of about 15 is observed. Concentrations as low as a few parts per billion of the pollutant can be detected with a good signal-to-noise ratio.     

Optimization of the operational parameters in a fast axial flow CW CO2 laser using artificial neural networks and genetic algorithms

This paper presents an artificial intelligence approach for optimization of the operational parameters such as gas pressure ratio and discharge current in a fast-axial-flow CW CO₂ laser by coupling artificial neural networks and genetic algorithm. First, a series of experiments were used as the learning data for artificial neural networks. The best-trained network was connected to genetic algorithm as a fitness function to find the optimum parameters. After the optimization, the calculated laser power increases by 33% and the measured value increases by 21% in an experiment as compared to a non-optimized case.     

Stochastic resonance in a stochastic bistable system subject to additive white noise and dichotomous noise

The stochastic resonance (SR) in a stochastic stable system driven by a static force and a periodic square-wave signal as well as by additive white noise and dichotomous noise is considered from the point of view of the signal-to-noise ratio (SNR). It is found that the SNR exhibits SR behavior when it is plotted as a function of the noise strength of the white noise and dichotomous noise, as well as when plotted as a function of the static force. Moreover, the influence of the strength of the stochastic potential force and the correlation rate of the dichotomous noise is investigated.     

Temperature tunable optical gratings in nematic elastomer

We have investigated the behaviour of temperature dependent periodic-index gratings fabricated in a nematic elastomer. The gratings have been obtained by photopolymerisation under a microscopy apparatus. Contraction properties, as well as diffraction properties, have been studied as a function of temperature. Unidirectional contraction has been demonstrated by means of circular figure deformation and the polarisation dependency of the diffraction by the gratings has been determined.     

Tunneling through bridges: Bohmian non-locality from higher-derivative gravity

A classical origin for the Bohmian quantum potential, as that potential term arises in the quantum mechanical treatment of black holes and Einstein–Rosen (ER) bridges, can be based on 4th-order extensions of Einstein's equations. The required 4th-order extension of general relativity is given by adding quadratic curvature terms with coefficients that maintain a fixed ratio, as their magnitudes approach zero, with classical general relativity as a singular limit. If entangled particles are connected by a Planck-width ER bridge, as conjectured by Maldacena and Susskind, then a connection by a traversable Planck-scale wormhole, allowed in 4th-order gravity, describes such entanglement in the ontological interpretation. It is hypothesized that higher-derivative gravity can account for the nonlocal part of the quantum potential generally.     

DBU液相催化法原位合成四苯氧基酞菁锌/ZnO复合材料的制备及光催化选择性研究

在负载于氧化铟锡(ITO)导电玻璃上、哑铃状纳米ZnO表面配位未饱和锌离子作为“模板”,以苯氧基邻苯二腈作为“分子碎片”,利用DBU液相催化法,在亲水性纳米ZnO表面,原位合成疏水性四苯氧基酞菁锌(ZnTPPc)。通过多种表征手段,分析证实了所合成的ZnTPPc分子结构、ZnTPPc/ZnO界面及光生电荷转移特性。在可见光下,分别以亲水性亚甲基蓝(MB)、疏水性苯酚(PL)及其混合液为待降解反应物,定量分析疏水性ZnTPPc/ZnO复合材料对降解疏水性PL的光催化选择性。结果表明： 原位合成ZnTPPc在ZnO表面呈现单分子层,具有较好的疏水性能,ZnTPPc可优先选择性降解疏水性PL,且在可见光光催化中对PL的相对降解效率是对MB分子的1.21倍。     

Enhancement of catalytic activity by increasing surface area in heterogeneous catalysis

The use of nanoclusters in systems with confined void spaces such as inside mesoporous or microporous solids appears to be an efficient way of preventing aggregation of nanoclusters in their catalytic application. Zeolite-Y is considered as a suitable host providing highly ordered supercages with a diameter of 1.3 nm. Intrazeolite metal(0) nanoclusters were prepared at room temperature by ion-exchange of metal cations with the extra framework Na⁺ ions in Zeolite-Y, followed by the reduction of the metal cations in the cavities of Zeolite-Y with sodium borohydride in aqueous solution, whereby the Zeolite-Y is reloaded with Na⁺ ions. Hence, host framework remains intact as shown by using a multi-prong approach. Intrazeolite transition-metal(0) nanoclusters were isolated by suction filtration and drying in vacuum at room temperature and characterized by a combination of analytical methods. Intrazeolite metal(0) nanoclusters were tested as catalyst in the hydrolysis of sodium borohydride and ammonia-borane, both of which have been considered as a promising hydrogen storage materials. High catalytic activity and the outstandingly long lifetime of intrazeolite transition-metal(0) nanoclusters catalyst in the hydrogen generation from the hydrolysis of both sodium borohydride and ammonia-borane is demonstrated. The results are attributed to the small size of the nanoclusters within the zeolite cages as well as prevention of agglomeration of the nanoclusters.     

Symbols of a cosmic order

The world runs on networks over which signals communicate sequences of symbols, e.g. numerals. Examining both engineered and natural communications networks reveals an unsuspected order that depends on contact with an unpredictable entity. This order has three roots. The first is a proof within quantum theory that no evidence can ever determine its explanation, so that an agent choosing an explanation must do so unpredictably. The second root is the showing that clocks that step computers do not “tell time” but serve as self-adjusting symbol-handling agents that regulate “logically synchronized” motion in response to unpredictable disturbances. Such a clock-agent has a certain independence as well as the capacity to communicate via unpredictable symbols with other clock-agents and to adjust its own tick rate in response to that communication. The third root is the noticing of unpredictable symbol exchange in natural systems, including the transmission of symbols found in molecular biology. We introduce a symbol-handling agent as a role played in some cases by a person, for example a physicist who chooses an explanation of given experimental outcomes, and in other cases by some other biological entity, and in still other cases by an inanimate device, such as a computer-based detector used in physical measurements. While we forbear to try to explain the propensity of agents at all levels from cells to civilizations to form and operate networks of logically synchronized symbol-handling agents, we point to this propensity as an overlooked cosmic order, an order structured by the unpredictability ensuing from the proof. Appreciating the cosmic order leads to a conception of agency that replaces volition by unpredictability and reconceives the notion of objectivity in a way that makes a place for agency in the world as described by physics. Some specific implications for physics are outlined.     

Electronic properties of self-assembled quantum dots of sodium on Cu(1 1 1) and their interaction with water

The electronic properties of thin films of Na on Cu(1 1 1) and their interaction with water have been investigated at room temperature by high resolution electron energy loss spectroscopy. The first Na layer is characterized by two features tentatively assigned to charge density waves. The second Na layer grows as small islands. The loss spectrum of this layer shows a feature at 3.0 eV identified as a Mie resonance. Increasing alkali coverage, Na islands form a continuous film, as indicated by the appearance of a Na surface plasmon and by the disappearance of the Mie resonance. Water vapour strongly interacts with Na layers as shown by the OH-Na vibration whose frequency shifts from 36 meV to 53 meV as a function of alkali coverage.     

一个强、弱耗散功能可分隔系统中的特征激变

报道一个由保守映象和耗散映象不连续、不可逆地分段描述的系统，以及在其中发生的一例特征激变.激变的独特之处在于逃逸孔洞.由映象的不连续、不可逆性而导致相平面中出现一个胖分形迭代禁区网，它使得一个混沌吸引子突然失稳而发生激变后出现的两个周期吸引子的吸引域边界成为点滴状.仅仅在每个周期点邻近存在这样的一个作为逃逸孔洞的、受到强耗散性支配和禁区边界限制的规则边界吸引域. 关键词： 激变 保守映象 耗散映象 逃逸孔洞     

Synthesis of monodisperse and high moment nickel–iron (NiFe) nanoparticles using modified polyol process

Monodisperse NiFe nanoparticles with different compositions have been successfully synthesized by surfactant free simple modified polyol method. In the process, polyethylene glycol was used as a solvent media and it has been found to play a key role to act as a reducing agent as well as a stabilizer simultaneously. XRD, TEM, and EDS analysis techniques were used to characterize the synthesized nanoparticles. TEM images displayed formation of a thin oxide layer around the nanoparticles, and confirmed by detection of some oxygen element using EDS measurement. The magnetic properties of the synthesized NiFe NPs samples were measured by vibrating sample magnetometer (VSM) at room temperature, and the saturation magnetization value was found to be iron content dependent.     

Large stereoscopic LED display by use of parallax barrier of aperture grille type (Invited Paper)

We propose a large parallax barrier by use of aperture grille. Main advantages of using aperture grille include no reflection and no absorption in apertures, as well as wide viewing angle. These advantages are investigated with theoretical calculations and experiments by use of several kinds of LED panels, such as a fine-pitch LED panel and a 140-inch large LED panel. Limitations of viewing angle by parallax barrier are analyzed in conventional black stripes on a transparent substrate type and in aperture grille type. Experimental results straw use of aperture grille increases contrast and reduce reflection on the aperture surface.