Superconducting On-chip Fourier Transform Spectrometer

The kinetic inductance effect is strongly nonlinear with applied current in NbTiN, TiN and NbN thin films. This can be utilized to realize novel devices. We present results from transmission lines made with these materials, where DC (current) control is used to modulate the phase velocity thereby enabling on-chip spectrometers. Utility of such compact spectrometers is discussed, along with their natural connection with parametric amplifiers

Charge dynamics in the half-metallic ferromagnet CrO\u3csub\u3e2\u3c/sub\u3e

Infrared spectroscopy is used to investigate the electronic structure and charge carrier relaxation in crystalline films of CrO2 which is the simplest of all half-metallic ferromagnets. Chromium dioxide is a bad metal at room temperature but it has a remarkably low residual resistivity (\u3c5 \u3eμΩ cm) despite the small spectral weight associated with free carrier absorption. The infrared measurements show that low residual resistivity is due to the collapse of the scattering rate at ω\u3c2000 \u3ecm-1. The blocking of the relaxation channels at low v and T can be attributed to the unique electronic structure of a half-metallic ferromagnet. In contrast to other ferromagnetic oxides, the intraband spectral weight is constant below the Curie temperature

Density of states determined from Monte Carlo simulations

We describe method for calculating the density of states by combining several canonical monte carlo runs. We discuss how critical properties reveal themselves in $g(\epsilon)$ and demonstrate this by applying the method several different phase transitions. We also demonstrate how this can used to calculate the conformal charge, where the dominating numerical method has traditionally been transfer matrix.Comment: Major revision of paper, several references added throughout. Current version accepted for publication in Phys. Rev.

Effects of Forage Chicory (\u3cem\u3eCichorium Intybus\u3c/em\u3e) On Farmed Deer Growth and Internal Parasitism

Internal parasitism (particularly lungworm - Dictyocaulus sp) significantly limits post-weaning growth of deer. Endoparasite control using anthelmintics may be unsustainable, due to the increasing risk of anthelmintic resistance and the risk or perception of chemical residues in animal products. Chicory has a high feeding value and contains sesquiterpene lactones and low levels of condensed tannins, both with anti-parasitic activity (Molan et al., 2003). Grazing chicory during autumn may reduce the requirement for anthelmintic treatment of young deer compared with grazing ryegrass-based pasture (Hoskin et al., 1999). The objective of this study was to investigate the effect of withholding anthelmintic treatment of young deer grazing grass-based pasture or chicory on autumn growth and internal parasitism

Atomic layer deposition of titanium nitride for quantum circuits

Superconducting thin films with high intrinsic kinetic inductance are of great importance for photon detectors, achieving strong coupling in hybrid systems, and protected qubits. We report on the performance of titanium nitride resonators, patterned on thin films (9-110 nm) grown by atomic layer deposition, with sheet inductances of up to 234 pH/square. For films thicker than 14 nm, quality factors measured in the quantum regime range from 0.4 to 1.0 million and are likely limited by dielectric two-level systems. Additionally, we show characteristic impedances up to 28 kOhm, with no significant degradation of the internal quality factor as the impedance increases. These high impedances correspond to an increased single photon coupling strength of 24 times compared to a 50 Ohm resonator, transformative for hybrid quantum systems and quantum sensing.Comment: 10 pages, 8 figures including supplemental material

Effective source approach to self-force calculations

Numerical evaluation of the self-force on a point particle is made difficult by the use of delta functions as sources. Recent methods for self-force calculations avoid delta functions altogether, using instead a finite and extended "effective source" for a point particle. We provide a review of the general principles underlying this strategy, using the specific example of a scalar point charge moving in a black hole spacetime. We also report on two new developments: (i) the construction and evaluation of an effective source for a scalar charge moving along a generic orbit of an arbitrary spacetime, and (ii) the successful implementation of hyperboloidal slicing that significantly improves on previous treatments of boundary conditions used for effective-source-based self-force calculations. Finally, we identify some of the key issues related to the effective source approach that will need to be addressed by future work.Comment: Invited review for NRDA/Capra 2010 (Theory Meets Data Analysis at Comparable and Extreme Mass Ratios), Perimeter Institute, June 2010, CQG special issue - 22 pages, 8 figure

Efficient Classical Simulation of Optical Quantum Circuits

We identify a broad class of physical processes in an optical quantum circuit that can be efficiently simulated on a classical computer: this class includes unitary transformations, amplification, noise, and measurements. This simulatability result places powerful constraints on the capability to realize exponential quantum speedups as well as on inducing an optical nonlinear transformation via linear optics, photodetection-based measurement and classical feedforward of measurement results, optimal cloning, and a wide range of other processes.Comment: 4 pages, published versio

Mating Ewes on Condensed Tannin-Containing Forages Increases Ewe Reproductive Rate and Reduces Lamb Mortality

Action of condensed tannin (CT) reduces forage protein degradation in the rumen and increases the absorption of amino acids from the small intestine (Barry & McNabb 1999). This paper reports the effects of grazing ewes on two CT-containing forages during mating upon ewe reproductive rate and lamb mortality

Superconducting On-chip Fourier Transform Spectrometer

The kinetic inductance effect is strongly nonlinear with applied current in NbTiN, TiN and NbN thin films. This can be utilized to realize novel devices. We present results from transmission lines made with these materials, where DC (current) control is used to modulate the phase velocity thereby enabling on-chip spectrometers. Utility of such compact spectrometers is discussed, along with their natural connection with parametric amplifiers