Extended Uniform Ginzburg-Landau Theory for Novel Multiband Superconductors

The recently discovered multiband superconductors have created a new class of novel superconductors. In these materials multiple superconducting gaps arise due to the formation of Cooper pairs on different sheets of the Fermi surfaces. An important feature of these superconductors is the interband couplings, which not only change the individual gap properties, but also create new collective modes. Here we investigate the effect of the interband couplings in the Ginzburg-Landau theory. We produce a general $\tau^{(2n+1)/2}$ expansion ($\tau = 1-T/T_c$) and show that this expansion has unexpected behaviour for $n\geq 2$. This point emphasises the weaker validity of the GL theory for lower temperatures and gives credence to the existence of hidden criticality near the critical temperature of the uncoupled subdominant band.Comment: 10 pages, 4 figure

Photoionization of the valence shells of the neutral tungsten atom

Results from large-scale theoretical cross section calculations for the total photoionization of the 4f, 5s, 5p and 6s orbitals of the neutral tungsten atom using the Dirac Coulomb R-matrix approximation (DARC: Dirac-Atomic R-matrix codes) are presented. Comparisons are made with previous theoretical methods and prior experimental measurements. In previous experiments a time-resolved dual laser approach was employed for the photo-absorption of metal vapours and photo-absorption measurements on tungsten in a solid, using synchrotron radiation. The lowest ground state level of neutral tungsten is $\rm 5p^6 5d^4 6s^2 \; {^5}D_{\it J}$, with $\it J$=0, and requires only a single dipole matrix for photoionization. To make a meaningful comparison with existing experimental measurements, we statistically average the large-scale theoretical PI cross sections from the levels associated with the ground state $\rm 5p^6 5d^4 6s^2 \; {^5}D_{\it J}[{\it J}=0,1,2,3,4]$ levels and the \rm 5d^56s \; ^7S_3 excited metastable level. As the experiments have a self-evident metastable component in their ground state measurement, averaging over the initial levels allows for a more consistent and realistic comparison to be made. In the wider context, the absence of many detailed electron-impact excitation (EIE) experiments for tungsten and its multi-charged ion stages allows current photoionization measurements and theory to provide a road-map for future electron-impact excitation, ionization and di-electronic cross section calculations by identifying the dominant resonance structure and features across an energy range of hundreds of eV.Comment: 10 pages, 3 figures, accepted for publication in J Phys B: At. Mol. Opt. Phy

Block Motion Changes in Japan Triggered by the 2011 Great Tohoku Earthquake

Plate motions are governed by equilibrium between basal and edge forces. Great earthquakes may induce differential static stress changes across tectonic plates, enabling a new equilibrium state. Here we consider the torque balance for idealized circular plates and find a simple scalar relationship for changes in relative plate speed as a function of its size, upper mantle viscosity, and coseismic stress changes. Applied to Japan, the 2011 $\mathrm{M}_{\mathrm{W}}=9.0$ Tohoku earthquake generated coseismic stresses of $10^2-10^5$~Pa that could have induced changes in motion of small (radius $\sim100$~km) crustal blocks within Honshu. Analysis of time-dependent GPS velocities, with corrections for earthquake cycle effects, reveals that plate speeds may have changed by up to $\sim3$ mm/yr between $\sim3.75$-year epochs bracketing this earthquake, consistent with an upper mantle viscosity of $\sim 5\times10^{18}$Pa$\cdot$s, suggesting that great earthquakes may modulate motions of proximal crustal blocks at frequencies as high as $10^-8$~Hz

The effect of a trapping procedure on the stress response of wild rainbow trout

Fish traps are a common research and management tool in which fish are subjected to procedures that elicit a stress response in other contexts. The effects of trapping on the stress response of sexually mature, wild rainbow trout Oncorhynchus mykiss were investigated during their upstream spawning migration by measuring concentrations of plasma cortisol, lactate, and glucose. Males had significantly lower basal plasma cortisol concentrations (6.1 ± 0.8 ng/mL [mean ± SE]) than females (21.4 ± 5.9 ng/mL). Similarly, the plasma cortisol response in males was significantly lower than that in females for all experiments. Fish working the barrier before entering the trap had increased concentrations of plasma cortisol. Confinement in the trap also induced a stress response. Plasma cortisol concentrations increased to 185.1 ± 40.9 ng/mL in males and 549.1 ± 60.1 ng/mL in females after confinement for 1 h. After processing, the magnitude of the stress response and the relative duration of recovery was less in fish that were confined longer in the trap. However, resting cortisol concentrations in females were not reached after 40 h of recovery in either group. Recovery to resting concentrations of plasma lactate occurred within 15 h after processing. In contrast, concentrations of plasma glucose remained significantly elevated at 40 h after processing. Postspawning fish had significantly lower plasma concentrations of cortisol, glucose, and lactate following application of an extreme stressor compared with prespawning fish. Based on the results of this study, we conclude that the trapping procedure induces a severe and prolonged stress response in wild rainbow trout