334 research outputs found
Thermally induced subgap features in the cotunneling spectroscopy of a carbon nanotube
We report on nonlinear cotunneling spectroscopy of a carbon nanotube quantum
dot coupled to Nb superconducting contacts. Our measurements show rich subgap
features in the stability diagram which become more pronounced as the
temperature is increased. Applying a transport theory based on the
Liouville-von Neumann equation for the density matrix, we show that the
transport properties can be attributed to processes involving sequential as
well as elastic and inelastic cotunneling of quasiparticles thermally excited
across the gap. In particular, we predict thermal replicas of the elastic and
inelastic cotunneling peaks, in agreement with our experimental results.Comment: 21 pages, 9 figures, submitted to New Journal of Physic
Asymptotic symmetries on Kerr--Newman horizon without anomaly of diffeomorphism invariance
We analyze asymptotic symmetries on the Killing horizon of the
four-dimensional Kerr--Newman black hole. We first derive the asymptotic
Killing vectors on the Killing horizon, which describe the asymptotic
symmetries, and find that the general form of these asymptotic Killing vectors
is the universal one possessed by arbitrary Killing horizons. We then construct
the phase space associated with the asymptotic symmetries. It is shown that the
phase space of an extreme black hole either has the size comparable with a
non-extreme black hole, or is small enough to exclude degeneracy, depending on
whether or not the global structure of a Killing horizon particular to an
extreme black hole is respected. We also show that the central charge in the
Poisson brackets algebra of these asymptotic symmetries vanishes, which implies
that there is not an anomaly of diffeomorphism invariance. By taking into
account other results in the literature, we argue that the vanishing central
charge on a black hole horizon, in an effective theory, looks consistent with
the thermal feature of a black hole. We furthermore argue that the vanishing
central charge implies that there are infinitely many classical configurations
that are associated with the same macroscopic state, while these configurations
are distinguished physically.Comment: 14 pages, v2: references added, minor corrections, v3: new pars and
refs. added and corresponding correction
Leptogenesis with Dirac Neutrinos
We describe a "neutrinogenesis" mechanism whereby, in the presence of
right-handed neutrinos with sufficiently small pure Dirac masses,
(B+L)-violating sphaleron processes create the baryon asymmetry of the
Universe, even when B=L=0 initially. It is shown that the resulting neutrino
mass constraints are easily fulfilled by the neutrino masses suggested by
current experiments. We present a simple toy model which uses this mechanism to
produce the observed baryon asymmetry of the Universe. (PostScript Errors
corrected in latest Version).Comment: 4 pages, Latex (using amsmath,feynmp,graphicx), 4 figure
Peripherally inserted central catheter‐related deep vein thrombosis: contemporary patterns and predictors
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/107486/1/jth12549.pd
Physical routes for the synthesis of kesterite
This paper provides an overview of the physical vapor technologies used to synthesize Cu2ZnSn(S,Se)4
thin films as absorber layers for photovoltaic applications. Through the years, CZT(S,Se) thin films
have been fabricated using sequential stacking or co-sputtering of precursors as well as using
sequential or co-evaporation of elemental sources, leading to high-efficient solar cells. In addition,
pulsed laser deposition of composite targets and monograin growth by the molten salt method were
developed as alternative methods for kesterite layers deposition. This review presents the growing
increase of the kesterite-based solar cell efficiencies achieved over the recent years. A historical
description of the main issues limiting this efficiency and of the experimental pathways designed to
prevent or limit these issues is provided and discussed as well. Afinal section is dedicated to the
description of promising process steps aiming at further improvements of solar cell efficiency, such as
alkali doping and bandgap grading1. R Caballero and M León acknowledge financial support via the Spanish Ministry of Science, Innovation and Universities project (WINCOST, ENE2016-80788-C5-2-R) and thank H2020 EU Programme under the project INFINITE-CELL (H2020-MSCA-RISE-2017-777968).
2. S Canulescu and J Schou acknowledge the support from Innovation Fund Denmark.
3. D-H Kim acknowledges financial support via the DGIST R&D Program of the Ministry of Science and ICT, KOREA (18-BD-05).
4.C. Malerba acknowledges the support from the Italian Ministry of Economic development in the framework of the Operating Agreement with ENEA for the Research on the Electric System.
5.A Redinger acknowledges financial support via the FNR Attract program, Project : SUNSPOT, Nr.11244141.
6. E Saucedo thanks H2020 EU Programme under the projects STARCELL (H2020-NMBP-03-2016-720907) and INFINITE-CELL (H2020-MSCA-RISE-2017-777968), the Spanish Ministry of Science, Innovation and Universities for the IGNITE project (ENE2017-87671-C3-1-R), and the European Regional Development Funds (ERDF, FEDER Programa Competitivitat de Catalunya 2007–2013). IREC belong to
the SEMS (Solar Energy Materials and Systems) Consolidated Research Group of the ‘Generalitat de Catalunya’ (Ref. 2017 SGR 862).
7. Taltech acknowledges financial support via the Estonian Ministry of Education and Research funding project IUT19-28 and the European Union Regional Development Fund, Project TK141.
8. B Vermang has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 Research and Innovation Programme (Grant Agreement No 715027
Peripherally inserted central catheter‐related deep vein thrombosis: contemporary patterns and predictors: reply
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109637/1/jth12721.pd
Age structure, dispersion and diet of a population of stoats (Mustela erminea) in southern Fiordland during the decline phase of the beechmast cycle
The dispersion, age structure and diet of stoats (Mustela erminea) in beech forest in the Borland and Grebe Valleys, Fiordland National Park, were examined during December and January 2000/01, 20 months after a heavy seed-fall in 1999. Thirty trap stations were set along a 38-km transect through almost continuous beech forest, at least 1 km apart. Mice were very scarce (nights, C/100TN) along two standard index lines placed at either end of the transect, compared with November 1999 (>60/100TN), but mice were detected (from footprints in stoat tunnels) along an 8 km central section of the transect (stations 14-22). Live trapping with one trap per station (total 317.5 trap nights) in December 2000 caught 2 female and 23 male stoats, of which 10 (including both females) were radio collared. The minimum range lengths of the two females along the transect represented by the trap line were 2.2 and 6.0 km; those of eight radio-tracked males averaged 2.9 ± 1.7 km. Stations 14-22 tended to be visited more often, by more marked individual stoats, than the other 21 stations.
Fenn trapping at the same 30 sites, but with multiple traps per station (1333.5 trap nights), in late January 2001 collected carcasses of 35 males and 28 females (including 12 of the marked live-trapped ones). Another two marked males were recovered dead. The stoat population showed no sign of chronic nutritional stress (average fat reserve index = 2.8 on a scale of 1-4 where 4 = highest fat content); and only one of 63 guts analysed was empty. Nevertheless, all 76 stoats handled were adults with 1-3 cementum annuli in their teeth, showing that reproduction had failed that season. Prey categories recorded in descending frequency of occurrence were birds, carabid beetle (ground beetle), weta, possum, rat, and mouse. The frequencies of occurrence of mice and birds in the diet of these stoats (10% and 48%, respectively) were quite different from those in stoats collected in Pig Creek, a tributary of the Borland River (87%, 5%), 12 months previously when mice were still abundant. Five of the six stoat guts containing mice were collected within 1 km of stations 14-22
Neutralino Dark Matter in Mirage Mediation
We study the phenomenology of neutralino dark matter (DM) in mirage mediation
scenario of supersymmetry breaking which results from the moduli stabilization
in some string/brane models. Depending upon the model parameters, especially
the anomaly to modulus mediation ratio determined by the moduli stabilization
mechanism, the nature of the lightest supersymmetric particle (LSP) changes
from Bino-like neutralino to Higgsino-like one via Bino-Higgsino mixing region.
For the Bino-like LSP, the standard thermal production mechanism can give a
right amount of relic DM density through the stop/stau-neutralino
coannihilation or the pseudo-scalar Higgs resonance process. We also examine
the prospect of direct and indirect DM detection in various parameter regions
of mirage mediation. Neutralino DM in galactic halo might be detected by near
future direct detection experiments in the case of Bino-Higgsino mixed LSP. The
gamma ray flux from Galactic Center might be detectable also if the DM density
profile takes a cuspy shape.Comment: One reference adde
Metastable Vacua in Flux Compactifications and Their Phenomenology
In the context of flux compactifications, metastable vacua with a small
positive cosmological constant are obtained by combining a sector where
supersymmetry is broken dynamically with the sector responsible for moduli
stabilization, which is known as the F-uplifting. We analyze this procedure in
a model-independent way and study phenomenological properties of the resulting
vacua.Comment: 21 pages, 19 figures; v2: matches version published in JHE
Axino dark matter from thermal production
The axino is a promising candidate for dark matter in the Universe. It is
electrically and color neutral, very weakly interacting, and could be - as
assumed in this study - the lightest supersymmetric particle, which is stable
for unbroken R-parity. In supersymmetric extensions of the standard model, in
which the strong CP problem is solved via the Peccei-Quinn mechanism, the axino
arises naturally as the fermionic superpartner of the axion. We compute the
thermal production rate of axinos in supersymmetric QCD. Using hard thermal
loop resummation, we obtain a finite result in a gauge-invariant way, which
takes into account Debye screening in the hot quark-gluon-squark-gluino plasma.
The relic axino abundance from thermal scatterings after inflation is
evaluated. We find that thermally produced axinos could provide the dominant
part of cold dark matter, for example, for an axino mass of 100 keV and a
reheating temperature of 10^6 GeV.Comment: 33 pages, 7 figures, 1 table, erratum adde
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