1,247 research outputs found
Microwave properties of : Influence of magnetic scattering
We report measurements of the surface impedance of
, . Increasing
concentration leads to some striking results not observed in samples doped
by non-magnetic constituents. The three principal features of the data
- multiple structure in the transition, a high residual resistance and, at high
concentrations, an upturn of the low data, are all characteristic of
the influence of magnetic scattering on superconductivity, and appear to be
common to materials where magnetism and superconductivity coexist. The low
behavior of appears to change from to at large
doping, and provides evidence of the influence of magnetic pairbreaking of the
.Comment: 5 pages, 3 eps figures, Revtex, 2-column format, uses graphicx. To
appear in Physica C. Postscript version also available at
http://sagar.physics.neu.edu/preprints.htm
Impurity induced density of states and residual transport in nonunitary superconductors
We obtain general expressions for the residual density of states, electrical
conductivity and thermal conductivity for non-unitary superconductors due to
impurity scattering. We apply the results to the so-called `B phase' of
PrOs4Sb12, which we describe using a non-unitary gap function derived from
symmetry considerations. The conductivity tensor has inequivalent diagonal
components due to off-axis nodal positions which may be detectable in
experiments.Comment: 8 pages, 1 figur
Evolution of crystalline electric field effects, superconductivity, and heavy fermion behavior in the specific heat of Pr(OsRu)Sb
Specific heat measurements were made on single crystals of the
superconducting filled skutterudite series Pr(OsRu)Sb
down to 0.6 K. Crystalline electric field fits in the normal state produced
parameters which were in agreement with previous measurements. Bulk
superconductivity was observed for all values of the Ru concentration with
transition temperatures consistent with previous experiments, confirming a
minimum in at . The data below appear to be more
consistent with power law behavior for (PrOsSb), and with
exponential behavior for . An enhanced electronic
specific heat coefficient was observed for , further
supporting as a critical concentration where the physical
properties abruptly change. Significant enhancement of above
the weak coupling value was only observed for and .Comment: 16 pages, 5 figures, submitted to Physical Review B. v2: text added
and figures modifie
High-pressure study of non-Fermi liquid and spin-glass-like behavior in CeRhSn
We present measurements of the temperature dependence of electrical
resistivity of CeRhSn up to ~ 27 kbar. At low temperatures, the electrical
resistivity varies linearly with temperature for all pressures, indicating
non-Fermi liquid behavior. Below a temperature Tf ~ 6 K, the electrical
resistivity deviates from a linear dependence. We found that the
low-temperature feature centered at T = Tf shows a pressure dependence dTf/dP ~
30 mK/kbar which is typical of canonical spin glasses. This interplay between
spin-glass-like and non-Fermi liquid behavior was observed in both CeRhSn and a
Ce0.9La0.1RhSn alloy.Comment: 5 pages, 3 figures, accepted for publication to Journal of Physics:
Condensed Matte
Identifying attack surfaces in the evolving space industry using reference architectures
The space environment is currently undergoing a substantial change and many new entrants to the market are deploying devices, satellites and systems in space; this evolution has been termed as NewSpace. The change is complicated by technological developments such as deploying machine learning based autonomous space systems and the Internet of Space Things (IoST). In the IoST, space systems will rely on satellite-to-x communication and interactions with wider aspects of the ground segment to a greater degree than existing systems. Such developments will inevitably lead to a change in the cyber security threat landscape of space systems. Inevitably, there will be a greater number of attack vectors for adversaries to exploit, and previously infeasible threats can be realised, and thus require mitigation. In this paper, we present a reference architecture (RA) that can be used to abstractly model in situ applications of this new space landscape. The RA specifies high-level system components and their interactions. By instantiating the RA for two scenarios we demonstrate how to analyse the attack surface using attack trees
- …