Integer quantum hall effect

Non-resonant fusion cross-sections significantly higher than corresponding theoretical predictions are observed in low-energy experiments with deuterated matrix target. Models based on thermal effects, electron screening, or quantum-effect dispersion relations have been proposed to explain these anomalous results: none of them appears to satisfactory reproduce the experiments. Velocity distributions are fundamental for the reaction rates and deviations from the Maxwellian limit could play a central role in explaining the enhancement. We examine two effects: an increase of the tail of the target Deuteron momentum distribution due to the Galitskii-Yakimets quantum uncertainty effect, which broadens the energy-momentum relation; and spatial fluctuations of the Debye-Hückel radius leading to an effective increase of electron screening. Either effect leads to larger reaction rates especially large at energies below a few keV, reducing the discrepancy between observations and theoretical ...

Non-resonant fusion cross-sections significantly higher than corresponding theoretical predictions are observed in low-energy experiments with deuterated matrix target. Models based on thermal effects, electron screening, or quantum-effect dispersion relations have been proposed to explain these anomalous results: none of them appears to satisfactory reproduce the experiments. Velocity distributions are fundamental for the reaction rates and deviations from the Maxwellian limit could play a central role in explaining the enhancement. We examine two effects: an increase of the tail of the target Deuteron momentum distribution due to the Galitskii-Yakimets quantum uncertainty effect, which broadens the energy-momentum relation; and spatial fluctuations of the Debye-Hückel radius leading to an effective increase of electron screening. Either effect leads to larger reaction rates especially large at energies below a few keV, reducing the discrepancy between observations and theoretical ...

Non-resonant fusion cross-sections significantly higher than corresponding theoretical predictions are observed in low-energy experiments with deuterated matrix target. Models based on thermal effects, electron screening, or quantum-effect dispersion relations have been proposed to explain these anomalous results: none of them appears to satisfactory reproduce the experiments. Velocity distributions are fundamental for the reaction rates and deviations from the Maxwellian limit could play a central role in explaining the enhancement. We examine two effects: an increase of the tail of the target Deuteron momentum distribution due to the Galitskii-Yakimets quantum uncertainty effect, which broadens the energy-momentum relation; and spatial fluctuations of the Debye-Hückel radius leading to an effective increase of electron screening. Either effect leads to larger reaction rates especially large at energies below a few keV, reducing the discrepancy between observations and theoretical ...

General relativity can have a significant impact on the long-range escape trajectories of solar sails deployed near the sun. Spacetime curvature in the vicinity of the sun can cause a solar sail traveling from 0.01 AU to 2550 AU to be deflected by as much as one million kilometers, and should therefore be taken into account at the beginning of the mission. There are a number of smaller general relativistic effects, such as frame dragging due to the slow rotation of the sun which can cause a deflection of more than one thousand kilometers.

We report real wave packet (WP) calculations of reaction probabilities, cross sections, rate constants, and product distributions of the reaction N(4S)+O2(X 3∑g−)→NO(X 2∏)+O(3P). We propagate initial WPs corresponding to several O2 levels, and employ reactant coordinates and a flux method for calculating initial-state-resolved observables, or product coordinates and an asymptotic analysis for calculating state-to-state quantities. Exact or J-shifting calculations are carried out at total angular momentum J=0 or J>0, respectively. We employ the recent X 2A′ S3 potential energy surface (PES) by Sayós et al. and the earlier a 4A′ PES by Duff et al. In comparing S3 results with the WP ones of a previous X 2A′ S2 PES, we find lower S3 energy thresholds and larger S3 probabilities, despite the higher S3 barrier. This finding is due to the different features of the doublet PESs in the reactant and product channels, at the transition state, and in the NO2 equilibrium region. We analyze t...

We compute the primordial scalar, vector and tensor metric perturbations arising from quantum field inflation. Quantum field inflation takes into account the nonperturbative quantum dynamics of the inflaton consistently coupled to the dynamics of the (classical) cosmological metric. For chaotic inflation, the quantum treatment avoids the unnatural requirements of an initial state with all the energy in the zero mode. For new inflation it allows a consistent treatment of the explosive particle production due to spinodal instabilities. Quantum field inflation (under conditions that are the quantum analog of slow roll) leads, upon evolution, to the formation of a condensate starting a regime of effective classical inflation. We compute the primordial perturbations taking the dominant quantum effects into account. The results for the scalar, vector and tensor primordial perturbations are expressed in terms of the classical inflation results. For a N -component field in a O(N ) symmetric model, adiabatic fluctuations dominate while isocurvature or entropy fluctuations are negligible. The results agree with the current WMAP observations and predict corrections to the power spectrum in classical inflation. Such corrections are estimated to be of the order of m 2 N H 2 , where m is the inflaton mass and H the Hubble constant at the moment of horizon crossing. An upper estimate turns to be about 4% for the cosmologically relevant scales. This quantum field treatment of inflation provides the foundations to the classical inflation and permits to compute quantum corrections to it.

In this project we have performed an study of the singularities in Clasical Cosmology, considering a flat Friedmann-Lemaitre-Robertson-Walker for a linear equation of state and for a non-linear one. We have computed analitically all the possible cases, obtaining as a result a general classification for the singularities for a model with a non-linear EoS.

The chemical potential and the capacitance of a model quantum dot have been computed, in- cluding contributions of exchange and correlation in the limit of 0 K temperature. The Schrodinger equation has been solved self-consistently, taking into account the electron-electron Coulomb in- teraction and many-body effects within the framework of density-functional theory. We have also studied the eKect of conducting backgates and of nearby electrodes using the method of images. Depending on the size of the dot, we derive a prevalence of either the quantization energy or the electrostatic energy: there is a smooth transition from predominant quantum eKects for small dots to classical capacitance behavior for large dots. Our simulation reproduces characteristic eKects that have been experimentally observed, such as the capacitance increase for increasing electron numbers and irregularities in the chemical potential values when randomly distributed charged impurities are present.

Calculations of the steady-state drift velocity and impact ionization rate of holes in the valence bands of GaAs and InP are presented based on a Monte Carlo simulation with the unique inclusion of a complete band structure (derived using the k-p method) and quantum effects such as collision broadening. The results are found to fit the experimental data well throughout an enormous range of applied electric fields. No appreciable anisotropy in the impact ionization rate is obtained theoretically in either material. The impact ionization rate in InP is much lower than in GaAs largely because of the greater density of states in InP and the corresponding higher hole-phonon scattering rate. A possible explanation of the difference in the ratio of electron over hole ionization rates in GaAs and InP is also presented.

Within the framework of the standard dielectric continuum model (DCM), we have performed a theoretical study of interface (IF) phonon modes in III-V semiconductor self-assembled quantum dots (SAQDs). We model the SAQD as a truncated cone whose growth-axis is along the polar axis of the cone. Small and arbitrary polar angle approximations are used to resolve the angular partial differential equation within the variables separation scheme of the LaplaceÕs equation. Our theory allows to obtain new features in the IF modes behavior as the geometry parameters change (aspect ratio and angle of the conical dot). In fact, IF eigenfrequencies present an abrupt change at determined angles, related with the change of sign in the IF dispersion law.

The geometric construction of the functional integral over coset spaces M/G is reviewed. The inner product on the cotangent space of infinitesimal deformations of M defines an invariant distance and volume form, or functional integration measure on the full configuration space. Then, by a simple change of coordinates parameterizing the gauge fiber G, the functional measure on the coset space M/G is deduced. This change of integration variables leads to a Jacobian which is entirely equivalent to the Faddeev-Popov determinant of the more traditional gauge fixed approach in non-abelian gauge theory. If the general construction is applied to the case where G is the group of coordinate reparametrizations of spacetime, the continuum functional inte

In the classical Josephson effect the phase difference across the junction is well defined, and the supercurrent is reduced only weakly by phase diffusion. For mesoscopic junctions with small capacitance the phase undergoes large quantum fluctuations, and the current is also decreased by Coulomb blockade effects. We discuss the behavior of the current-voltage characteristics in a large range of parameters comprising the phase diffusion regime with coherent Josephson current as well as the supercurrent peak due to incoherent Cooper pair tunneling in the Coulomb blockade regime. 1.

The treatment of quantum effects in gravitational fields indicates that pure states may evolve into mixed states, and Hawking has proposed modifications of the axioms of field theory which incorporate the corresponding violation of quantum mechanics. In this paper we propose a modified Hamiltonian equation of motion for density matrices and use it to interpret upper bounds on the violation of quantum mechanics in different. .. phenomenological situations. We apply our formalism to the K"-K" system and to long baseline neutron interferometry experiments.-In both cases we find upper bounds of about 2 x 10s21 GeV on contributions to the single particle "Hamiltonian" which violate quantum mechanical coherence. We discuss how these limits might be improved-.". . in the future, and consider the relative significance of other successful tests of quantum mechanics. An Appendix contains model estimates of the magnitude of effects violating quantum mechanics.

The P → ∞ limit was considered in the spherical P-spin glass. It is possible to store information in the vacuum configuration of ferromagnetic phase. Maximal allowed level of noise was calculated in ferromagnetic phase. Derrida's model [1,2] has been applied for optimal coding [3-6]. One chooses couplings

The quantum statistical treatment of the Rutherford model, considering matter as a system of point charges (electrons and nuclei), is analyzed. First, in the historical context, the solutions of different fundamental problems, such as the divergence of the partition function, elaborated by Herzfeld, Planck, Brillouin and Rompe, are discussed. Beyond this, the modern state of art is presented and new results are given which explain why bound states according to a discrete part of the spectra occur only in a valley in the temperature‐density plane. Based on the actual state of the quantum statistics of Coulomb systems, virial expansions within the canonical ensemble and the grand ensemble and combinations are derived. The following transitions along isotherms are studied: (i) the formation of bound states occurring by increasing the density from low to moderate values, (ii) the disappearance of bound state effects at higher densities due to medium effects. Within the physical picture ...

Perfect nanowires may be studied from both the bandstructure and transmission perspectives, and relating features in one set of curves to those in another often yields much insight into their behavior. For random-alloy nanowires, however, only transmission characteristics and virtual-crystal approximation (VCA) bands have been available. This is a serious shortcoming since the VCA cannot properly capture disorder at the primitive cell level: those bulk properties which it can satisfactorily reproduce arise from spatially extended states and measurements which average out primitive cell-level fluctuations. Here we address this deficiency by projecting approximate bands out of supercell states for Al 0 15 Ga 0 85 As random alloy nanowires. The resulting bands correspond to the transmission characteristics very closely, unlike the VCA bands, which cannot explain important transmission features. Using both bandstructure and transmission results, we are better able to explain the operation of these nanowires.

A highly phosphorus δ-doped Si device is modeled with a quantum well with periodic boundary conditions and the semi-empirical spds* tight-binding band model. Its temperaturedependent electronic properties are studied. To account for high doping density with many electrons, a highly parallelized selfconsistent Schrödinger-Poisson solver is used with atomistic representations of multiple impurity ions. The band-structure in equilibrium and the corresponding Fermi-level position are computed for a selective set of temperatures. The result at room temperature is compared with previous studies and the temperature-dependent electronic properties are discussed further in detail with the calculated 3-D self-consistent potential profile.

We use a functional approach to study various aspects of the quantum effective dynamics of moving, planar, dispersive mirrors, coupled to scalar or Dirac fields, in different numbers of dimensions. We first compute the Euclidean effective action, and use it to derive the imaginary part of the 'inout' effective action. We also obtain, for the case of the real scalar field in 1 + 1 dimensions, the Schwinger-Keldysh effective action and a semiclassical Langevin equation that describes the motion of the mirror including noise and dissipative effects due to its coupling to the quantum fields.

In order to integrate quantum mechanics into geometrical theories of physics, new quantities must be included in the description of the infinitesimal structure of space-time. Using gauge transformations, Weyl's coefficients of connection are generalized to include not just the metric tensor and the electromagnetic potential, but the wave function as well. As the field equations are developed, it is found that invariance of the scalar of curvature under the appropriate gauge and coordinate transformations implies the Klein-Gordon equation. Since the terms required for invafiance correspond with known quantum effects, no invariant classical limit is possible. The selection of appropriate fixed gauges and the elimination of small terms does lead directly to the Hamilton-Jacobi equations. Trajectories are defined for all cases, and as an example, the Lorentz force law is derived from these trajectories. The probability density is related to the particle trajectories and a eonformal parameter of an additional metric tensor. Because of the gauge transformation, gravitational, electromagnetic, and quantum effects must be described as aspects of the same geometrical structure.

Lawrence K. Wang, Yung-Tse Hung, Howard H. Lo, Constantine Yapijakis (2006) . Hazardous Industrial Waste Treatment,  CRC Press, Boca Raton, Forida, USA; 526 pages, ISBN:  9780429126628; DOI :  https://doi.org/10.1201/9780849375750      .....  ABSTRACT:  Featuring chapters from the bestselling Handbook of Industrial and Hazardous Wastes Treatment, Second Edition, this resource presents valuable strategies culled from the latest technologies and keen insights of experts in the field.  Hazardous Industrial Waste Treatment explains industry and waste-specific analyses and treatment methods for industrial and hazardous waste materials - from explosive wastes to landfill leachate to wastes produced by metal finishing, photographic, and timber processing. Additional information covers the means of monitoring waste on site, pollution, and site remediation, and includes a timely evaluation of the role of biotechnology in contemporary industrial waste management.

We generalise the classical Transition by Breaking of Analyticity for the class of Frenkel-Kontorova models studied by Aubry and others to non-zero Planck's constant and temperature. This analysis is based on the study of a renormalization operator for the case of irrational mean spacing using Feynman's functional integral approach. We show how existing classical results extend to the quantum regime. In particular we extend MacKay's renormalization approach for the classical statistical mechanics to deduce scaling of low frequency effects and quantum effects. Our approach extends the phenomenon of hierarchical melting studied by Vallet, Schilling and Aubry to the quantum regime.

An optomechanical sensor suitable for the study of quantum effects has been developed and characterized. The sensor reads out the vibrations of a microfabricated miniature silicon mechanical oscillator which forms one end mirror of a high finesse Fabry-Pe ´rot cavity. The mechanical quality factor is up to Qϭ300 000 at 300 K and rises up to Qϭ4ϫ10 6 at 4 K. The thermal noise of the oscillator has been measured in the time and frequency domains at room temperature and at 4.5 K. The prospects for observing the standard quantum limit are discussed. ͓S1050-2947͑99͒07002-X͔

There is evidence that superpositions of states of non-composite quantum systems A exist and can be interpreted as the simultaneous existence of two or more physically distinct quantum states of A. This paper shows, however, that entangled superposition states have a quite different character from simple superposition states. Whereas a simple superposition superposes two coherent states of a non-composite object A, entangled states superpose correlations between states of two incoherent subsystems A and B of a composite system AB. Thus an entangled state is best conceptualized as a coherent or phase-dependent superposition of correlations between incoherent or phase-independent subsystem states.

A brief review is given about the role strong magnetic fields play in the universe. We list the main observational and theoretical achievements treated in the following chapters including a number of open questions which future research is going to attack. Strong fields in the universe exceed any large scale fields by several orders of magnitude, at first glance suggesting that their generation mechanisms would be different. However, it is believed that gravitational collapse and magnetic flux conservation is responsible for the amplification of fields generated in the progenitors to the observed strengths. In this sense the extremely strong fields are mainly fossil, and their variety confirms the different masses and stages where the collapse comes to rest, at the lightest in white dwarfs and at the strongest in magnetars, which are a particular class of neutron stars with strongly inhomogeneous particularly structured crust. Various effects related to the detection of such fields,...