Anomalous thermopower and Nernst effect in CeCoIn5\rm CeCoIn_5: entropy-current loss in precursor state

The heavy-electron superconductor CeCoIn$_5$ exhibits a puzzling precursor state above its superconducting critical temperature at $T_c$ = 2.3 K. The thermopower and Nernst signal are anomalous. Below 15 K, the entropy current of the electrons undergoes a steep decrease reaching $\sim$0 at $T_c$. Concurrently, the off-diagonal thermoelectric current $\alpha_{xy}$ is enhanced. The delicate sensitivity of the zero-entropy state to field implies phase coherence over large distances. The prominent anomalies in the thermoelectric current contrast with the relatively weak effects in the resistivity and magnetization.Comment: 5 figures, 4 page

The Lorenz number in CeCoIn5_5 inferred from the thermal and charge Hall currents

The thermal Hall conductivity $\kappa_{xy}$ and Hall conductivity $\sigma_{xy}$ in CeCoIn$_5$ are used to determine the Lorenz number ${\cal L}_H$ at low temperature $T$. This enables the separation of the observed thermal conductivity into its electronic and non-electronic parts. We uncover evidence for a charge-neutral, field-dependent thermal conductivity, which we identify with spin excitations. At low $T$, these excitations dominate the scattering of charge carriers. We show that suppression of the spin excitations in high fields leads to a steep enhancement of the electron mean-free-path, which leads to an interesting scaling relation between the magnetoresistance, thermal conductivity and $\sigma_{xy}$.Comment: 6 pages, 7 figures Intro para slightly lengthened. Added 2 new re

Influence of environmental factors on birth weight variability of indigenous Serbian breeds of sheep

The present investigation was carried out to study the influence of environmental factors on the birth weight variability of two breeds of sheep. Animals used in this research were taken from the Pirot and Svrljig indigenous sheep breeds. The data were collected from 1999 to 2009 and were analyzed to determine the effect of the year and season, age of the lamb, weight of the lamb, birth type and sex on the birth weight of lambs. Both sheep breeds were managed in the same farm and under the same farm conditions. Statistical analysis was performed by using GLM procedure of SAS statistical package program. Results showed that young (2 to 3 years) and old (6 to 7 years) mothers gave birth to lighter lambs, while sheep in the middle age (4 to 5 years) gave birth to lambs with the heaviest body weight. However, the differences were respectively significant (P < 0.01). Birth weight of lambs also depended on weight of lamb, although differences in the average body weight of lambs were statistically significant (P < 0.05). Type of birth also had effect on the body weight of lambs at birth in both Pirot and Svrljig breeds (P < 0.05). Body weight of lambs at birth were almost the same for both sexes (3.39 and 3.36 kg for male and female in Pirot breed and 3.48 and 3.43 kg for male and female in Svrljig breed, respectively), though the difference was not statistically significant (P > 0.05). The values of birth weight observed for quite a number of years ranged from 3.27 to 3.52 kg in Pirot and 3.34 to 3.51 kg in Svrljig breed (P < 0.01). Lambs born in the spring-summer season has the heaviest body weight at birth. Conversely, the significant difference (P < 0.05) can only be interpreted as the factor of food source.Key words: Environmental factors, birth weight variability, indigenous sheep

Evidence for electron-phonon interaction in Fe1−x_{1-x}Mx_{x}Sb2_{2} (M=Co, Cr) single crystals

We have measured polarized Raman scattering spectra of the Fe$_{1-x}$Co$_{x}$Sb$_{2}$ and Fe$_{1-x}$Cr$_{x}$Sb$_{2}$ (0$\leq x\leq$0.5) single crystals in the temperature range between 15 K and 300 K. The highest energy $B_{1g}$ symmetry mode shows significant line asymmetry due to phonon mode coupling width electronic background. The coupling constant achieves the highest value at about 40 K and after that it remains temperature independent. Origin of additional mode broadening is pure anharmonic. Below 40 K the coupling is drastically reduced, in agreement with transport properties measurements. Alloying of FeSb$_2$ with Co and Cr produces the B$_{1g}$ mode narrowing, i.e. weakening of the electron-phonon interaction. In the case of A$_{g}$ symmetry modes we have found a significant mode mixing

On the role of fine-sand dune dynamics in controlling water depth changes in Rio Parapeti, Serrania Borebigua (Southern sub-Andean zone of Bolivia)

The role of the fine-dune sand dynamics in controlling the natural regeneration of the upper layer of a riverbed used for filtration is studied at the Choreti test reach of Rio Parapeti, in the Southern sub-Andean zone of Bolivia. Local production of drinking water relies on Riverbed Filtration, the delivery of which depends on the river water depth and the riverbed permeability. There is a strong, natural, declamation process of the upper layer maintained by dune bed-forms migrating downstream. It is thus essential to understand and represent local water depth changes as a function of the incoming discharge. We show the vortex-drag model can be used to correctly calculate the stream velocity in natural environment. Then we study the sand dunes characteristic (wavelength and celerity) in the Rio Parapeti. Because of the shallow-flow configuration the dominant dune length can be easily extracted from satellite images taken at various dates. We also show that it is more than likely that dune movement can be followed by the simple deployment of a pressure probe into the water under stable discharge condition, even if further data and investigation are necessary to confirm this

Comment on "Spatial optical solitons in highly nonlocal media" and related papers

In a recent paper [A. Alberucci, C. Jisha, N. Smyth, and G. Assanto, Phys. Rev. A 91, 013841 (2015)], Alberucci et al. have studied the propagation of bright spatial solitary waves in highly nonlocal media. We find that the main results in that and related papers, concerning soliton shape and dynamics, based on the accessible soliton (AS) approximation, are incorrect; the correct results have already been published by others. These and other inconsistencies in the paper follow from the problems in applying the AS approximation in earlier papers by the group that propagated to the later papers. The accessible soliton theory cannot describe accurately the features and dynamics of solitons in highly nonlocal media.Comment: 2 page

Topological Quantum Computing with Only One Mobile Quasiparticle

In a topological quantum computer, universal quantum computation is performed by dragging quasiparticle excitations of certain two dimensional systems around each other to form braids of their world lines in 2+1 dimensional space-time. In this paper we show that any such quantum computation that can be done by braiding $n$ identical quasiparticles can also be done by moving a single quasiparticle around n-1 other identical quasiparticles whose positions remain fixed.Comment: 4 pages, 5 figure