Intrinsic fluctuations in sub 10-nm double-gate MOSFETs introduced by discreteness of charge and matter

We study, using numerical simulation, the intrinsic parameter fluctuations in sub 10 nm gate length double gate MOSFETs introduced by discreteness of charge and atomicity of matter. The employed "atomistic" drift-diffusion simulation approach includes quantum corrections based on the density gradient formalism. The quantum confinement and source-to-drain tunnelling effects are carefully calibrated in respect of self-consistent Poisson-Schrodinger and nonequilibrium Green's function simulations. Various sources of intrinsic parameter fluctuations, including random discrete dopants in the source/drain regions, single dopant or charged defect state in the channel region and gate line edge roughness, are studied in detail

Critical loads for nutrient nitrogen for soil-vegetation systems

Members of the UK Critical Loads Advisory Group (CLAG) have calculated critical loads for nutrient nitrogen to produce maps for Great Britain. The results of three methods, based upon the conclusions from the Lokeberg workshop are described below. Two of these methods use the empirical approachand the other the steady state equation ("mass balance") for nitrogen saturation

Simulation of direct source-to-drain tunnelling using the density gradient formalism: Non-Equilibrium Greens Function calibration

Quantum mechanical confinement effects, gate, hand-to-hand and source-to-drain tunnelling will dramatically affect the characteristics of future generation nanometre scaled devices. It has been demonstrated already that first-order quantum corrections, which satisfactorily describe quantum confinement effects, can be introduced into efficient TCAD orientated drift-diffusion simulators using the density gradient approach. In this paper we refer to Non-Equilibrium Green's Function simulations in order to calibrate the density gradient formalism in respect of both confinement and source-to-drain tunnelling using different effective masses in directions normal and parallel to the conducting channel. We demonstrate that the density gradient formalism can describe accurately the current characteristics in sub 20 nm double gate MOSFETs

Generalized Parton Distributions of the Pion

Off-forward structure functions of the pion are investigated in twist-two and twist-three approximation. A simple model is used for the pion, which allows to introduce finite size effects, while preserving gauge invariance. Results for the imaginary parts of the gamma^* pi -> gamma^* pi off-forward amplitude and of the structure functions are presented. Generalized Callan-Gross relations are obtained.Comment: 4 pages, 5 figures, LaTeX, uses espcrc2.sty (included), presented at QCD03 Conference, Montpellier, France, July 200

Spatio-temporal patterns of crab fisheries in the main bays of Guangdong Province, China

Using a semi-balloon otter trawl, crab fisheries in the main bays of Guangdong Province, China, were carried out seasonally . A total of 70 species were found, all belonging to the South China Sea Faunal sub region in the tropical India-West-Pacific Faunal Region. The clustering and nMDS ordination analysis revealed the existence of three groups. Group 1 included Hailing Bay and four bays to its east where typical species were Portunus sanguinolentus, P. pelagicus and Charybdis feriatus. Group 2 included Shuidong Bay and Leizhou Bay where typical species were P. sanguinolentus, P. pelagicus and P. hastatoides. Group 3 was Liusha Bay where typical species were C. feriatus, C. vadorum and C. truncate. The spatial and temporal variations of crab fisheries were mainly associated with characteristics of the sediment, seasonal changes and their own biological characteristics, but not significantly with water depth, temperature, salinity, and the “mid-summer fishing moratorium” conservation measure

General relativistic spinning fluids with a modified projection tensor

An energy-momentum tensor for general relativistic spinning fluids compatible with Tulczyjew-type supplementary condition is derived from the variation of a general Lagrangian with unspecified explicit form. This tensor is the sum of a term containing the Belinfante-Rosenfeld tensor and a modified perfect-fluid energy-momentum tensor in which the four-velocity is replaced by a unit four-vector in the direction of fluid momentum. The equations of motion are obtained and it is shown that they admit a Friedmann-Robertson-Walker space-time as a solution.Comment: Submitted to General Relativity and Gravitatio

Variations of radiocarbon in tree rings: southern hemisphere offset preliminary results

The Queen's University of Belfast, Northern Ireland and University of Waikato, Hamilton, New Zealand radiocarbon laboratories have undertaken a series of high-precision measurements on decadal samples of dendrochronologically dated oak (Quercus patrea) and cedar (Libocedrus bidwillii) from Great Britain and New Zealand, respectively. The results show a real atmospheric offset of 3.4 ± 0.6% (27.2 ± 4.7 ¹⁴C yr) between the two locations for the interval AD 1725 to AD 1885, with the Southern Hemisphere being depleted in ¹⁴C. This result is less than the value currently used to correct Southern Hemisphere calibrations, possibly indicating a gradient in Δ¹⁴C within the Southern Hemisphere

The Quark Propagator from the Dyson-Schwinger Equations: I. the Chiral Solution

Within the framework of the Dyson-Schwinger equations in the axial gauge, we study the effect that non-perturbative glue has on the quark propagator. We show that Ward-Takahashi identities, combined with the requirement of matching perturbative QCD at high momentum transfer, guarantee the multiplicative renormalisability of the answer. Technically, the matching with perturbation theory is accomplished by the introduction of a transverse part to the quark-gluon vertex. We show that this transverse vertex is crucial for chiral symmetry breaking, and that massless solutions exist below a critical value of the strong coupling constant. Using the gluon propagator that we previously calculated, we obtain small corrections to the quark propagator, which keeps a pole at the origin in the chiral phase.Comment: 21 pages, 6 figures; McGill/94-24, SHEP 93/94-26 We generalise our results by showing that they are not sensitive to the specific choice that we make for the transverse vertex. We illustrate that fact in two new figure

Langevin Simulation of Thermally Activated Magnetization Reversal in Nanoscale Pillars

Numerical solutions of the Landau-Lifshitz-Gilbert micromagnetic model incorporating thermal fluctuations and dipole-dipole interactions (calculated by the Fast Multipole Method) are presented for systems composed of nanoscale iron pillars of dimension 9 nm x 9 nm x 150 nm. Hysteresis loops generated under sinusoidally varying fields are obtained, while the coercive field is estimated to be 1979 $\pm$ 14 Oe using linear field sweeps at T=0 K. Thermal effects are essential to the relaxation of magnetization trapped in a metastable orientation, such as happens after a rapid reversal of an external magnetic field less than the coercive value. The distribution of switching times is compared to a simple analytic theory that describes reversal with nucleation at the ends of the nanomagnets. Results are also presented for arrays of nanomagnets oriented perpendicular to a flat substrate. Even at a separation of 300 nm, where the field from neighboring pillars is only $\sim$ 1 Oe, the interactions have a significant effect on the switching of the magnets.Comment: 19 pages RevTeX, including 12 figures, clarified discussion of numerical technique