Electric field induced charge noise in doped silicon: ionization of phosphorus donors

We report low frequency charge noise measurement on silicon substrates with different phosphorus doping densities. The measurements are performed with aluminum single electron transistors (SETs) at millikelvin temperatures where the substrates are in the insulating regime. By measuring the SET Coulomb oscillations, we find a gate voltage dependent charge noise on the more heavily doped substrate. This charge noise, which is seen to have a 1/f spectrum, is attributed to the electric field induced tunneling of electrons from their phosphorus donor potentials.Comment: 4 page, 3 figure

Metamaterials for light rays: ray optics without wave-optical analog in the ray-optics limit

Volumes of sub-wavelength electromagnetic elements can act like homogeneous materials: metamaterials. In analogy, sheets of optical elements such as prisms can act ray-optically like homogeneous sheet materials. In this sense, such sheets can be considered to be metamaterials for light rays (METATOYs). METATOYs realize new and unusual transformations of the directions of transmitted light rays. We study here, in the ray-optics and scalar-wave limits, the wave-optical analog of such transformations, and we show that such an analog does not always exist. Perhaps, this is the reason why many of the ray-optical possibilities offered by METATOYs have never before been considered.Comment: 10 pages, 3 figures, references update

Earth - venus trajectories, 1968-69, volume 4, part b

Earth-venus trajectories 1968-196

Quaternion Analysis for Generalized Electromagnetic Fields of Dyons in Isotropic Medium

Quaternion analysis of time dependent Maxwell's equations in presence of electric and magnetic charges has been developed and the solutions for the classical problem of moving charges (electric and magnetic) are obtained in unique, simple and consistent manner

Evidence for the Presence of Thin and Heterogenous Dust Deposits on Ryugu's Boulders From Hayabusa2 MARA and Sample Data

Middle infrared spectral results obtained in-situ by the Hayabusa2 MARA instrument are generally in-line with previous results and a new comparison with sample C0137 returned from asteroid (162173) Ryugu, being similar to an aqueously altered CI1 chondrite. The mid-IR spectrum of the boulder on Ryugu measured by MARA is shallower around 9 μm compared to the laboratory spectrum of C0137. Here we show that discontinuous, fine dust deposits can partially explain the differences in the spectral data and remain in agreement with the temperature observations of the boulder by MARA if an opaque dust layer covers less than 3% of the field of view. Such a presence of dust covering a low porosity boulder was discounted by previous analysis of the mid-infrared MARA data which did not consider a highly porous boulder as we do here

Evaluation of the CNS and cardiovascular effects of prolonged exposure to bromotrifluromethane (CBrF3)

The proposed use of bromotrifluoromethane (CBrF3) as a fire extinguishant in aircraft, spacecraft and submarines has stimulated increasing interest and research in the toxicological properties of this compound. In a spacecraft, because of its unique recirculating life support system, the introduction of CBrF3 by leakage or intentional discharge, will result in continuous exposure of crewman to low concentrations of this compound for periods of up to 7 days, or possibly even longer. The effects of low concentrations of CBrF3, under continuous exposure conditions, on the CNS and cardiovascular systems of animals to enable an assessment of these risks were investigated

Observing sub-microsecond telegraph noise with the radio frequency single electron transistor

Telegraph noise, which originates from the switching of charge between meta-stable trapping sites, becomes increasingly important as device sizes approach the nano-scale. For charge-based quantum computing, this noise may lead to decoherence and loss of read out fidelity. Here we use a radio frequency single electron transistor (rf-SET) to probe the telegraph noise present in a typical semiconductor-based quantum computer architecture. We frequently observe micro-second telegraph noise, which is a strong function of the local electrostatic potential defined by surface gate biases. We present a method for studying telegraph noise using the rf-SET and show results for a charge trap in which the capture and emission of a single electron is controlled by the bias applied to a surface gate.Comment: Accepted for publication in Journal of Applied Physics. Comments always welcome, email [email protected], [email protected]

Nonholonomic Ricci Flows: II. Evolution Equations and Dynamics

This is the second paper in a series of works devoted to nonholonomic Ricci flows. By imposing non-integrable (nonholonomic) constraints on the Ricci flows of Riemannian metrics we can model mutual transforms of generalized Finsler-Lagrange and Riemann geometries. We verify some assertions made in the first partner paper and develop a formal scheme in which the geometric constructions with Ricci flow evolution are elaborated for canonical nonlinear and linear connection structures. This scheme is applied to a study of Hamilton's Ricci flows on nonholonomic manifolds and related Einstein spaces and Ricci solitons. The nonholonomic evolution equations are derived from Perelman's functionals which are redefined in such a form that can be adapted to the nonlinear connection structure. Next, the statistical analogy for nonholonomic Ricci flows is formulated and the corresponding thermodynamical expressions are found for compact configurations. Finally, we analyze two physical applications: the nonholonomic Ricci flows associated to evolution models for solitonic pp-wave solutions of Einstein equations, and compute the Perelman's entropy for regular Lagrange and analogous gravitational systems.Comment: v2 41 pages, latex2e, 11pt, the variant accepted by J. Math. Phys. with former section 2 eliminated, a new section 5 with applications in gravity and geometric mechanics, and modified introduction, conclusion and new reference

Generation of spin currents via Raman scattering

We show theoretically that stimulated spin flip Raman scattering can be used to inject spin currents in doped semiconductors with spin split bands. A pure spin current, where oppositely oriented spins move in opposite directions, can be injected in zincblende crystals and structures. The calculated spin current should be detectable by pump-probe optical spectroscopy and anomalous Hall effect measurement

A super-analogue of Kontsevich's theorem on graph homology

In this paper we will prove a super-analogue of a well-known result by Kontsevich which states that the homology of a certain complex which is generated by isomorphism classes of oriented graphs can be calculated as the Lie algebra homology of an infinite-dimensional Lie algebra of symplectic vector fields.Comment: 15 page