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The quantum mechanical effects has wide applications in quantum plasma echoes, quantum plasma instabilities and microelectronics devices.Quantum effects may become important when the electron number density of the order of 1030 m−3 andsmall temperatures of a few thousand Kelvin. A dusty plasma is a three-component plasma consisting of electrons,ions, and a solid grains.We use the quantum hydrodynamic model to derive the plasma dispersion equation to study the growth rate of electron drift waves in quantum dusty plasmas. The growth shows depends on the electron temperature, electron density, electron drift velocity and wave number, ions and dust mass. The results may be useful to understand the physics of dense astrophysical objects. Different approximations are tried to solve the dispersion equation. [ABSTRACT FROM AUTHOR]

The long standing hierarchy problem in particle physics addresses the 19 orders of magnitudes difference in interaction between electromagnetic forces and gravitation. Referring to string and conformal field theories it is commonly agreed that the weakness of gravity can in general be assigned to extra-dimensions (holographic principle). But there are no practical rules regarding dimensional adjustments and proper dynamic scaling improving the coupling of fields with different dimensionality, i.e. transforming electromagnetic flux into higher-dimensional gravitational fields for space propulsion purposes. Regarding the flux volume there is in any case a characteristic power-law scaling between length and time or mass scales with exponent proportional to the number of spatial dimensions. As a requirement of unification and adjustment, power-laws with different exponents should intersect at the unit scale since any power of 1 is 1. The basic reference and gravitational unit scale is given by a Kepler dynamics with unit radius and unit angular velocity that can be assigned to a gravitational unit source |mG|= |4 π2/G|. At this scale topologically different fields, sources of interaction and correspondent characteristic length and mass scales can be compared via Gauss law, where a quantum flux number NG connects the unit scale and the quantum scale. In our System of Units (SI) NG ∝ c4 can be found by dividing the unit length by the Planck length, consequently NG measures the weakness of gravity at the unit scale, where the Compton photon scale is given by the geometric mean and inversion symmetry between the unit and the Planck scale. Fields of applications could be in solid state superconductors (exotic materials) able to host high-dimensional network flux topologies with proper scaling and dynamics. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

The quantum principles of superposition and entanglement have led to a recasting of the foundations of information and computation theory, and are especially helpful in understanding the nature of privacy. The most private information, exemplified by a quantum eraser experiment, is best regarded as existing only conditionally and temporarily—after the experiment is over no trace remains. Less private is classically-secret information—quantum information that has decohered, and thus become recoverable in principle, though not in practice, from portions of the environment. Finally there is public information, which has been replicated so thoroughly throughout the environment as to be infeasible to conceal. The Internet has caused an explosion of public information, with the beneficial side effect of making it harder for despots to rewrite the history of their misdeeds, and it is tempting to hope that all macroscopic information is permanent, making such cover-ups impossible in principle if not in practice. However, by comparing entropy flows into and out of the Earth with estimates of the planet’s storage capacity, we conclude that most macroscopic information—for example the pattern of sand grains on an ancient beach—is impermanent, in the sense of becoming irrecoverable in principle from the Earth though still recorded in the Universe. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

We have studied whether repeated exposure to complicated physics concepts, such as quantum tunneling, fosters increased understanding. For three students, we have multiple interview, survey, and examination data over three years. We present data from a single student whose understanding of energy conservation in tunneling improved with repeated instruction, but whose ability to correctly sketch wave function solutions and discuss their meaning showed little progress. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

Other than scattering problems where perturbation theory is applicable, there are basically two ways to solve problems in physics. One is to reduce the problem to harmonic oscillators, and the other is to formulate the problem in terms of two-by-two matrices. If two oscillators are coupled, the problem combines both two-by-two matrices and harmonic oscillators. This method then becomes a powerful research tool to cover many different branches of physics. Indeed, the concept and methodology in one branch of physics can be translated into another through the common mathematical formalism. It is noted that the present form of quantum mechanics is largely a physics of harmonic oscillators. Special relativity is the physics of the Lorentz group which can be represented by the group of by two-by-two matrices commonly called SL(2, c). Thus the coupled harmonic oscillators can therefore play the role of combining quantum mechanics with special relativity. Both Paul A. M. Dirac and Richard P. Feynman were fond of harmonic oscillators, while they used different approaches to physical problems. Both were also keenly interested in making quantum mechanics compatible with special relativity. It is shown that the coupled harmonic oscillators can bridge these two different approaches to physics. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

According to Bell's theorem, every theory based on local realism is at variance with certain predictions of quantum mechanics. A theory that maintains realism but abandons reliance on locality, which has been proposed by Leggett, is incompatible with experimentally observable quantum correlations. In our experiment correlation measurements of spin-energy entangled single-neutrons violate a Leggett-type inequality by more than 7.6 standard deviations. The experimental data falsify the contextual realistic model and are fully in favor of quantum mechanics. [ABSTRACT FROM AUTHOR]

Classical turbulence research is advancing by utilizing MEMS temperature and pressure fluctuation sensor technology. Turbulence research at cryogenic temperatures has many advantages over the classical approach, such as extreme stability of control parameters and very high Reynolds numbers in small apparatus. However, changes in material properties from room temperature to 1 K (and below) make most sensors unusable at low temperature. A new type of thermistor, incorporating a Ge-film deposited on a GaAs substrate, has been designed. It provides high sensitivity in the range of 20 mK to 5 K. In this paper, the design and characteristics of these sensors is discussed, and experimental data from three thermistors is presented. Progress on a miniature pressure transducer is also described. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]