publicationDate stringlengths 1 2.79k | title stringlengths 1 36.5k ⌀ | abstract stringlengths 1 37.3k ⌀ | id stringlengths 9 47 |
|---|---|---|---|
1997-12-06 | Atmospheric neutrino interactions in Soudan-2 | A new measurement of the atmospheric numu/nue ratio-of-ratios, 0.61 +- 0.15
+- 0.05, has been obtained using a 3.2-kty exposure of the Soudan-2 underground
detector. This measurement, based upon neutrino reactions in an iron tracking
calorimeter of honeycomb-lattice geometry, is in agreement with the anomalously
low va... | 9712281v1 |
1998-08-24 | Limits on Pauli principle violation by nucleons | We consider nuclei produced in core collapse supernovae and subjected to a
high neutron flux. We show that an accelerator mass spectrometry experiment
that searched for traces of anomalous iron isotopes could set limits on the
order of $10^{-20}-10^{-25}$ on (or perhaps discover) Pauli principle violation
by neutrons. ... | 9808397v1 |
1999-11-12 | Muon's Behaviors under Bremsstrahlung with both the LPM effect and the Ter-Mikaelian effect and Direct Pair Production with the LPM effect | Differential and integral cross sections of the muon are calculated in the
materials: water, standard rock, iron and lead with and without the LPM effect.
The corresponding cross sections are also calculated with dielectric supression
effect (Ter-Mikaelian effect), in addition to the LPM effect. To demonstrate
the impo... | 9911330v1 |
2000-09-13 | Nuclear effects and higher twists in F3 structure function | We analyze the CCFR collaboration iron target data on the xF3 structure
function making particular emphasis on the extraction of the higher twist
contributions from data. Corrections for nuclear effects are applied in order
to extract data on the structure function of the isoscalar nucleon. Our
analysis confirms the ob... | 0009150v1 |
2000-12-06 | Can We Observe the Quark Gluon Plasma in Cosmic Ray Showers ? | The possibility of detection of some features of high energy particle
interactions with detectors placed at medium depths underground through studies
on high energy muons is investigated. These muons carry information about the
early interactions occurring during the development of the hadron cascade near
the top of th... | 0012068v3 |
2001-12-14 | Differential Distributions for NLO Analyses of Charged Current Neutrino-Production of Charm | Experimental analyses of charged current deep inelastic charm production --
as observed through dimuon events in neutrino-iron scattering -- measure the
strangeness component of the nucleon sea. A complete analysis requires a Monte
Carlo simulation to account for experimental detector acceptance effects;
therefore, a f... | 0112191v1 |
2003-09-09 | Re/Os constraint on the time-variability of the fine-structure constant | We argue that the accuracy by which the isochron parameters of the decay
$^{187}{\rm Re}\to ^{187}{\rm Os}$ are determined by dating iron meteorites may
not directly constrain the possible time-dependence of the decay rate and hence
of the fine-structure constant $\alpha$. From this point of view, some of the
attempts ... | 0309087v2 |
2003-10-01 | NUFACT'03: The Fate of the Clones | We present a Neutrino-Factory-based setup with three detectors of different
kind in principle capable to solve the eightfold-degeneracy in the simultaneous
measurement of $\theta_{13}$ and $\delta$, for $\theta_{13} \geq 1^\circ
(\sin^2 (2 \theta_{13}) \geq 10^{-3})$. Our setup includes a Superbeam-driven
water Cherenk... | 0310014v1 |
2004-08-23 | Possible Explanations for the NuTeV Weinberg Angle Measurement | The NuTeV collaboration has made an independent determination of the Weinberg
angle by measuring charged and neutral-current cross sections from neutrino and
antineutrino DIS on iron. Their value differs by 3 standard deviations from
that obtained from measurements at the Z pole. We review this experiment and
assess va... | 0408243v2 |
2005-09-22 | Moments of nuclear and nucleon structure functions at low Q^2 and the momentum sum rule | New nuclear structure function data from Jefferson Lab covering the higher x
and lower Q^2 regime make it possible to extract the higher order F_2 moments
for iron and deuterium at low four-momentum transfer squared Q^2. These moments
allow for an experimental investigation of the nuclear momentum sum rule and a
direct... | 0509241v2 |
2005-12-09 | New solutions for the color-flavor locked strangelets | Recent publications rule out the negatively charged beta equilibrium
strangelets in ordinary phase, and the color-flavor locked (CFL) strangelets
are reported to be also positively charged. This letter presents new solutions
to the system equations where CFL strangelets are slightly negatively charged.
If the ratio of ... | 0512112v1 |
2006-10-04 | Can we learn something more on oscillations from atmospheric neutrinos? | We show that for long-baseline experiments using a Mt water Cerenkov detector
atmospheric neutrino data provide a powerful method to resolve parameter
degeneracies. In particular, the combination of long-baseline and atmospheric
data increases significantly the sensitivity to the neutrino mass hierarchy and
the octant ... | 0610053v1 |
1999-12-23 | On the discovery of doubly-magic $^{48}$Ni | The paper reports on the first observation of doubly-magic Nickel-48 in an
experimental at the SISSI/LISE3 facility of GANIL. Four Nickel-48 isotopes were
identified. In addition, roughly 100 Nickel-49, 50 Iron-45, and 290 Chromium-42
isotopes were observed. This opens the possibility to search for two-proton
emission ... | 9912012v1 |
2006-09-06 | Dynamics Of Hadronization From Nuclear Semi Inclusive Deep Inelastic Scattering | The CLAS experiment E02-104, part of the EG2 run at Jefferson Lab, was
performed to study the hadronization process using semi inclusive deep
inelastic scattering off nuclei. Electron beam energy of 5 GeV and the CLAS
large acceptance detector were used to study charged pion production. The high
luminosity available at... | 0609005v1 |
1997-03-17 | Fermionic Molecular Dynamics: Multifragmentation in heavy-ion collisions and in excited nuclei | Within Fermionic Molecular Dynamics we investigate fragmentation of a
compound system which was created in a heavy-ion collision at a beam energy in
the Fermi energy domain and the decay of excited iron nuclei. We show that in
FMD many-body correlations play an important role in the formation of
fragments. | 9703035v1 |
1997-07-17 | Total and Parity-Projected Level Densities of Iron-Region Nuclei in the Auxiliary Fields Monte Carlo Shell Model | We use the auxiliary-fields Monte Carlo method for the shell model in the
complete $(pf+0g_{9/2})$-shell to calculate level densities. We introduce
parity projection techniques which enable us to calculate the parity dependence
of the level density. Results are presented for $^{56}$Fe, where the calculated
total level ... | 9707027v1 |
2000-09-05 | Signature of a Pairing Transition in the Heat Capacity of Finite Nuclei | The heat capacity of iron isotopes is calculated within the interacting shell
model using the complete $(pf+0g_{9/2})$-shell. We identify a signature of the
pairing transition in the heat capacity that is correlated with the suppression
of the number of spin-zero neutron pairs as the temperature increases. Our
results ... | 0009006v1 |
2000-12-08 | Effect of nuclear structure on Type Ia supernova nucleosynthesis | The relationship among nuclear structure, the weak processes in nuclei, and
astrophysics becomes quite apparent in supernova explosion and nucleosynthesis
studies. In this brief article, I report on progress made in the last few years
on calculating electron capture and beta-decay rates in iron-group nuclei. I
also rep... | 0012027v1 |
2002-01-10 | Neutral-current neutrino reactions in the supernova environment | We study the neutral-current neutrino scattering for four nuclei in the iron
region. We evaluate the cross sections for the relevant temperatures during the
supernova core collapse and derive Gamow-Teller distributions from large-scale
shell-model calculations. We show that the thermal population of the excited
states ... | 0201025v1 |
2003-03-06 | Gamow-Teller strength distributions in Fe and Ni stable isotopes | We study Gamow-Teller strength distributions in some selected nuclei of
particular Astrophysical interest within the iron mass region. The theoretical
framework is based on a proton-neutron Quasiparticle Random Phase Approximation
built on a deformed selfconsistent mean field basis obtained from two-body
density-depend... | 0303015v1 |
2006-07-27 | Spin projection in the shell model Monte Carlo method and the spin distribution of nuclear level densities | We introduce spin projection methods in the shell model Monte Carlo approach
and apply them to calculate the spin distribution of level densities for
iron-region nuclei using the complete $(pf+g_{9/2})$-shell. We compare the
calculated distributions with the spin-cutoff model and extract an
energy-dependent moment of i... | 0607062v1 |
2000-03-22 | RF-induced evaporative cooling and BEC in a high magnetic field | We present the design of our iron-core electromagnet for BEC, and how to
solve the specific experimental problems raised by this technique. After
presenting the experimental set-up, we address the interruption of runaway
evaporative cooling when the Zeeman effect is not linear. We present the ways
to circumvent this pr... | 0003050v1 |
2007-02-13 | LHCb Level-0 Trigger Detectors | The calorimeter and muon systems are essential components to provide a
trigger for the LHCb experiment. The calorimeter system comprises a
scintillating pad detector and pre-shower, followed by electromagnetic and
hadronic calorimeters. The calorimeter system allows photons, electrons and
hadrons to be identified, and ... | 0702103v1 |
2006-03-21 | Quantum description of spin tunneling in magnetic molecules: a new view | Starting from a phenomenological Hamiltonian originally written in terms of
angular momentum operators we derive a new quantum angle-based Hamiltonian that
allows for a discussion on the quantum spin tunneling. The study of the
applicability of the present approach, carried out in calculations with a
soluble quasi-spin... | 0603183v1 |
2007-02-06 | Spin tunneling in magnetic molecules: Quantitative estimates for Fe8 clusters | Spin tunneling in the particular case of the magnetic molecular cluster
octanuclear iron(III), Fe8, is treated by an effective Hamiltonian that allows
for an angle-based description of the process. The presence of an external
magnetic field along the easy axis is also taken into account in this
description. Analytic ex... | 0702051v1 |
2007-04-19 | Iron Line Profiles from Relativistic Thick Accretion Disk | We present a new code for calculating the Fe Kalpha line profiles from
relativistic accretion disks with finite thickness around a rotating black
hole. The thin Keplerian accretion disk must become thicker and sub-Keplerian
with increasing accretion rates. We here embark on, for the first time, a fully
relativistic com... | 0704.2460v1 |
2007-04-20 | Neutrino beams as a probe of the nuclear isospin and spin-isospin excitations | We explore the possibility of performing nuclear structure studies using low
energy neutrino beams. In particular, low energy beta-beams and conventional
sources (muon decay-at-rest) are considered. We present results on the total
charged-current as well as flux-averaged cross sections associated to electron
(anti)-neu... | 0704.2724v2 |
2007-05-14 | On the Enhanced Reverse Beta Processes in Graphene-Iron Composite Nanostructures at High Temperatures in Strong Magnetic Field | Strong dense many-spin interactions have been proposed to organize novel
orbital dynamics (the Little Effect) for novel chemical and catalytic
phenomena. The recent determinations of the relativistic and quantum Hall
effects of carriers in graphene under strong magnetic confinement have
substantiated the Little Effect.... | 0705.1909v1 |
2007-06-22 | A cool R Coronae Borealis star Z UMi | The high resolution spectra of a R CrB type star Z UMi are analysed. The
atmospheric parameters of Z UMi are estimated: Teff=5250+/-250K and log
g=0.5+/-0.3. This places Z UMi among the coolest R CrB stars. The hydrogen
deficiency of Z UMi is confirmed. The abundances of other elements resemble
those found for the mino... | 0706.3271v1 |
2007-06-27 | Molecular dynamics simulations of the dipolar-induced formation of magnetic nanochains and nanorings | Iron, cobalt and nickel nanoparticles, grown in the gas phase, are known to
arrange in chains and bracelet-like rings due to the long-range dipolar
interaction between the ferromagnetic (or super-paramagnetic) particles. We
investigate the dynamics and thermodynamics of such magnetic dipolar
nanoparticles for low densi... | 0706.3920v1 |
2007-07-23 | Magic Baseline Beta Beam | We study the physics reach of an experiment where neutrinos produced in a
beta-beam facility at CERN are observed in a large magnetized iron calorimeter
(ICAL) at the India-based Neutrino Observatory (INO). The CERN-INO distance is
close to the so-called "magic" baseline which helps evade some of the parameter
degenera... | 0707.3367v1 |
2007-08-09 | The Rest-Frame UV Spectrum of Elliptical Galaxies at High Redshift | Beyond redshift ~1.4 the only spectral feature that allows one to get the
redshift of passively evolving galaxies (PEG) with optical spectrographs is a
characteristic structure due to a set of iron and magnesium lines lines at
2600-2850 Angstrom in the rest frame. The same feature permits also to estimate
the time elap... | 0708.1240v1 |
2007-09-03 | Galactic neutrino background from cosmic ray interaction with the ISM content | We use a diffusive model for the propagation of Galactic cosmic rays to
estimate the charged pion production in interactions with protons of the
interstellar medium. Cosmic ray nuclei from proton to iron are considered and
the corresponding contribution to the neutrino secondary flux produced as a
result of spallation ... | 0709.0278v2 |
2007-09-06 | Structural peculiarities of plastically-deformed cementite and their influence on magnetic characteristics and Mossbauer parameters | Cementite Fe3C is studied with first-principles calculations. Two possible
positions of carbon atoms in the iron sublattice are considered: with prismatic
or octahedral environment. Mossbauer spectra (MS) with parameters calculated
for both modifications are simulated above and below the Curie temperature. A
possibilit... | 0709.0789v1 |
2007-11-28 | Nuclear effects in F_3 structure function of nucleon | We study nuclear effects in the $F^A_3(x)$ structure function in the deep
inelastic neutrino reactions on iron by using a relativistic framework to
describe the nucleon spectral functions in the nucleus.
The results for the ratio $R(x,Q^2)=\frac{F^A_3(x,Q^2)}{AF^N_3(x, Q^2)}$ and
the Gross-Llewellyn Smith(GLS) integr... | 0711.4443v2 |
2007-12-05 | Investigating Possible Neutrino Decay in Long Baseline Experiment Using ICAL as Far end Detector | We investigate the effects of possible decay of neutrinos from a neutrino
factory in a long baseline experiment. We consider the neutrinos from a factory
at CERN and the detector to be the 50 kTon iron calorimeter (ICAL) detector
proposed for India-based Neutrino Observatory (INO). We found considerable
depletion of mu... | 0712.0697v2 |
2007-12-20 | On the Simbol-X capability of detecting red/blue-shifted emission and absorption Fe K lines | The detection of red/blue-shifted iron lines in the spectra of astronomical
X-ray sources is of great importance, as it allows to trace the environment
around compact objects, like black holes in AGNs. We report on extensive
simulations to test the Simbol-X capability of detecting such spectral
features, focusing on th... | 0712.3427v1 |
2008-01-16 | Light-induced scattering and energy transfer between orthogonally-polarized waves | We present a detailed experimental investigation on polarization-isotropic
and polarization-anisotropic holographic scattering in lithium niobate crystal
doped with iron when recording parasitic gratings with an ordinary polarized
pump beam. The kinetics of both types of scattering during the whole process of
recording... | 0801.2489v1 |
2008-01-30 | Long-range magnetic order and spin-lattice coupling in the delafossite CuFeO2 | The electronic and magnetic properties of the delafossite CuFeO2 are
investigated by means of electronic structure calculations. They are performed
using density functional theory in the generalized gradient approximation as
well as the new full-potential augmented spherical wave method. The
calculations reveal three d... | 0801.4787v1 |
2008-01-31 | The Impact of Transit Observations on Planetary Physics | We highlight the importance of transit observations on understanding the
physics of planetary atmospheres and interiors. Transmission spectra and
emission spectra allow us to characterize this exotic atmospheres, which
possess TiO, VO, H2O, CO, Na, and K, as principal absorbers. We calculate
mass-radius relations for w... | 0801.4943v1 |
2008-02-06 | The Suppression and Recovery of the Ferroelectric Phase in Multiferroic $MnWO_4$ | We report the discovery of a complete suppression of ferroelectricity in
$MnWO_4$ by 10 % iron substitution and its restoration in external magnetic
fields. The spontaneous polarization in $Mn_{0.9}Fe_{0.1}WO_4$ arises below 12
K in external fields above 4 T. The magnetic/ferroelectric phase diagram is
constructed from... | 0802.0839v1 |
2008-03-31 | Hole superconductivity in Arsenic-Iron compounds | Superconductivity above 25K, and possibly above 40K, has recently been
discovered in $LaO_{1-x}F_xFeAs$ and related compounds. We propose that this is
another example of the mechanism of hole superconductivity at play. This
requires the existence of hole carriers at the Fermi energy, which appears to
contradict current... | 0804.0002v1 |
2008-04-03 | Understanding the Unique Structural and Electronic Properties of SrFeO2 | We report a first-principles study of SrFeO$_2$, an infinite-layer oxide with
Fe atoms in a perfect square-planar coordination down to essentially 0 K. Our
results reveal this striking behavior relies on the double occupation of the
3$d_{z^2}$ orbitals of high-spin Fe$^{2+}$. Such an electronic state results
from the h... | 0804.0495v1 |
2008-04-21 | Unusual magnetic behavior in ferrite hollow nanospheres | We report unusual magnetic behavior in iron oxide hollow nanospheres of 9.3
$nm$ in diameter. The large fraction of atoms existing at the inner and outer
surfaces gives rise to a high magnetic disorder. The overall magnetic behavior
can be explained considering the coexistence of a soft superparamagnetic phase
and a ha... | 0804.3292v1 |
2008-04-24 | Graphene-protected iron layer on Ni(111) | Here we report the photoemission studies of intercalation process of Fe
underneath graphene layer on Ni(111). The process of intercalation was
monitored via XPS of corresponding core levels and UPS of the graphene-derived
$\pi$ states in the valence band. \textit{fcc}-Fe films with thickness of 2-5
monolayers at the in... | 0804.3942v1 |
2008-04-24 | 19-F NMR Investigation of Iron-pnictide Superconductor LaFeAsO(0.89)F(0.11) | We report 19-F NMR investigation of the new high temperature superconductor
LaFeAsO(0.89)F(0.11) (Tc ~ 28K). We demonstrate that low frequency spin
fluctuations exhibit pseudo gap behavior above Tc. We also deduce the London
penetration depth lambda from NMR line broadening below Tc. | 0804.4026v3 |
2008-04-25 | Structural, magnetic and electronic properties of quaternary oxybismuthides LaOMBi (where M = Sc, Ti ... Ni, Cu) - possible parent phases for new superconducting materials | The extensive ab initio total energy calculations using the VASP-PAW method
with the generalized gradient approximation (GGA) for the exchange-correlation
potential are applied to systematic investigation of structural, electronic and
magnetic properties in quaternary oxybismuthides LaOMBi (where M = Sc, Ti...Ni,
Cu). ... | 0804.4064v1 |
2008-05-23 | Normal State Correlated Electronic Structure of Iron Pnictides | We describe the correlated electronic structure of a prototype Fe-pnictide
superconductor, $SmO_{1-x}F_{x}FeAs$, using LDA+DMFT. Strong, multi-orbital
electronic correlations generate a low-energy pseudogap in the undistorted
phase, giving a bad, incoherent metal in qualitative agreement with
observations. Very good se... | 0805.3636v1 |
2008-05-26 | Observation of magnetic field lines in the vicinity of a superconductor with the naked eye | Meissner effect and pinning effect are clearly observed with the naked eye. A
GdBaCuO high-temperature superconductor (HTS) disk fabricated by Nippon Steel
Corporation, a 100mm cubic NdFeB sintered magnet, and iron wires coated by
colored are used. When the HTS is put in the magnetic field of the magnet, it
can be obse... | 0805.3990v4 |
2008-06-05 | Low temperature synthesis and pressure induced insulator-metal transition of the newly found NdFeAsO0.75 | As low as 900 oC, iron-based layered quaternary compound NdFeAsO0.75 was
synthesized through solid state reaction method. XRD measurements illustrate
almost pure phase of tetragonal phase NdFeAsO was formed. The synthesis
temperature in our experiment is the lowest among all the reported methods
without the help of any... | 0806.0976v1 |
2008-06-11 | On superconducting and magnetic properties of iron-oxypnictides | Pairing symmetry in oxypnictides, a new family of multiband high-Tc
superconductors, is partially imposed by the positions of multiple Fermi
pockets, which itself can give rise to new order parameters, such as s+,-
states or the state of dx^2-y^2 symmetry. Other pairing states may appear on
small pockets for long range... | 0806.1933v2 |
2008-06-14 | Pressure-induced superconductivity in PrOxFeAs | Superconductivity with Tc of 45 K was realized in the tetragonal
ZrCuSiAs-type PrOxFeAs (x=0.75) under heat treatment of 1300 oC and pressure of
6 GPa for 2 hours. Although the sample prepared at 900 oC in vaccum possessed
the same phase as that treated in pressure, the electrical transport
measurement showed the simil... | 0806.2379v1 |
2008-06-17 | Improved parameters of the hydrogen-deficient binary star KSPer | Using the high resolution spectral observations obtained with the Nasmyth
Echelle Spectrograph NES of the 6m telescope we analysed the optical spectrum
of the hydrogen-deficient binary star KSPer. The atmospheric parameters derived
are: effective temperature Teff=9500+/-300 K, surface gravity log g=2.0+/-0.5,
and micro... | 0806.2709v1 |
2008-06-19 | Real Space Coulomb Interaction: A Pairing Glue for FeAs Superconductors | In this paper we present a real space pairing glue for the iron-based layered
superconductors. It is shown that two static electrons embedded symmetrically
into two adjacent Fe plaquettes of the superconductor can be bounded due to the
Coulombic interaction. The pairing mechanism favors the existence of the
pseudogap i... | 0806.3125v2 |
2008-06-25 | Mossbauer Spectroscopy Determination of iron foreign phases in the Superconducting Systems; RAsFeO1-x, RAsFeO1-xFx and Sr1-xKxFe2As2 | The recently discovered superconducting - spin density wave materials,
containing Fe and As, have raised huge interest. However most materials
prepared to date, suffer from a varying degree of content of foreign Fe-As
phases, Fe2As, FeAs2 and FeAs, which can lead to wrong conclusions concerning
the properties of these ... | 0806.4078v1 |
2008-06-26 | Some improvements of the ART method for finding transition pathways on potential energy surfaces | The Activation-Relaxation Technique nouveau (ARTn) is an eigenvector
following method for systematic search of saddle points and transition pathways
on a given potential energy surface. We propose a variation of this method
aiming at improving the efficiency of the local convergence close to the saddle
point. We prove ... | 0806.4354v1 |
2008-07-14 | Superconductivity in SrFe_(2-x)Co_xAs_2: Internal Doping of the Iron Arsenide Layers | In the electron doped compounds SrFe_(2-x)Co_xAs_2 superconductivity with T_c
up to 20 K is observed for 0.2 < x < 0.4. Results of structure determination,
magnetic susceptibility, electrical resistivity, and specific heat are
reported. The observation of bulk superconductivity in all thermodynamic
properties -- despit... | 0807.2223v1 |
2008-07-14 | Structure and superconductivity of LiFeAs | The lithium ions in Lithium iron arsenide phases with compositions close to
LiFeAs have been located using powder neutron diffraction. These phases exhibit
superconductivity at temperatures at least as high as 16 K demonstrating that
superconductivity in compounds with [FeAs]- anti-PbO-type anionic layers occurs
in com... | 0807.2228v2 |
2008-07-31 | Superconductivity in nickel-based compound GdONiBi and hole doped Gd0.9Sr0.1ONiBi | We successfully synthesized the nickel-based compound GdONiBi with
superconducting transition temperature about 4.5 K. By partially substituting
the element Gd with Sr to introduce holes into the material, we got new
superconductor Gd0.9Sr0.1ONiBi with critical temperature about 4.7 K. The
normal state resistivity in n... | 0807.5045v1 |
2008-08-04 | Superconductivity in Co-doped SmFeAsO | Here we report the synthesis and basic characterization of SmFe1-xCoxAsO
(x=0.10, 0.15). The parent compound SmFeAsO itself is not superconducting but
shows an antiferromagnetic order near 150 K, which must be suppressed by doping
before superconductivity emerges. With Co-doping in the FeAs planes,
antiferromagnetic or... | 0808.0197v2 |
2008-08-13 | Superconductivity in layered iron Selenide induced by cobalt- and sodium-doping | Superconductivity with zero resistance transition temperature (Tc) up to 8.4
K and 8.3 K can be obtained by doping cobalt and sodium in alfa-FeSe with the
nominal composition of Fe0.92Co0.08Se and Na0.1FeSe, respectively. The
electrical resistivity and AC magnetic susceptibility of the prepared samples,
measured with p... | 0808.1784v1 |
2008-08-14 | Heteroepitaxial growth and optoelectronic properties of layered iron oxyarsenide, LaFeAsO | Epitaxial thin films of LaFeAsO were fabricated on MgO (001) and
mixed-perovskite (La, Sr)(Al, Ta)O3 (001) single-crystal substrates by pulsed
laser deposition using a Nd:YAG second harmonic source and a 10 at.% F-doped
LaFeAsO disk target. Temperature dependences of the electrical resistivities
showed no superconducti... | 0808.1956v2 |
2008-08-28 | Electric excitation of spin resonance in antiferromagnetic conductors | Antiferromagnetism couples electron spin to its orbital motion, thus allowing
excitation of electron-spin transitions by an ac electric rather than magnetic
field - with absorption, exceeding that of common electron spin resonance at
least by four orders of magnitude. In addition to potential applications in
spin elect... | 0808.3946v2 |
2008-08-30 | A new family of iron pnictides: BaFeAs2 and BaFeSb2 | We investigate the structural, electronic, and magnetic properties of the
hypothetical compound BaFePn2 (Pn = As and Sb), which is isostructural to the
parent compound of the high temperature superconductor LaFeAsO1-xFx. Using
density functional theory, we show that the Fermi surface, electronic structure
and the spin ... | 0809.0041v2 |
2008-09-03 | Imaging the antiparallel magnetic alignment of adjacent Fe and MnAs thin films | The magnetic coupling between iron and alpha - MnAs in the epitaxial system
Fe/MnAs/GaAs(001) has been studied at the sub-micron scale, using element
selective x-ray photoemission electron microscopy. At room temperature, MnAs
layers display ridges and grooves, alternating alpha (magnetic) and beta
(non-magnetic) phase... | 0809.0620v1 |
2008-09-08 | Pressure Study of Superconducting Oxypnictide LaFePO | Electrical resistivity and magnetic susceptibility measurements under high
pressure were performed on an iron-based superconductor LaFePO. A steep
increase in superconducting transition temperature (Tc) of LaFePO with dTc/dP >
4 K/GPa to a maximum of 8.8 K for P = 0.8 GPa was observed. These results are
similar to isoc... | 0809.1239v1 |
2008-09-10 | Structural and electronic response upon hole-doping of rare-earth iron oxyarsenides Nd1-xSrxFeAsO (0 < x < 0.2) | Hole-doping of NdFeAsO via partial replacement of Nd3+ by Sr2+ is a
successful route to obtain superconducting phases (Tc = 13.5 K for a Sr2+
content of 20%); however, the structural and electronic response with doping is
different from and non-symmetric to that in the electron-doped side of the
phase diagram. | 0809.1755v1 |
2008-09-17 | Phonon Density of States in Nd(O$_{1-x}$F$_{x}$)FeAs | We report measurements of the phonon density-of-states in iron oxypnictide
superconductors by inelastic x-ray scattering. A good agreement with ab-initio
calculations that do not take into account strong electronic correlations is
found, and an unpredicted softening of phonon branches under F doping of these
compounds ... | 0809.2898v1 |
2008-10-08 | Pressure-induced superconductivity in Iron pnictide compound SrFe2As2 | Electrical resistivity under high pressure have been measured on nominally
pure SrFe2As2 up to 14 GPa. The resistivity drop appeared with increasing
pressure, and we clearly observed zero resistivity. The maximum of
superconducting transition temperature (Tc) is 38 K. The value is corresponding
to the one of optimally ... | 0810.1377v1 |
2008-10-17 | Magnetic Phase Diagram of FeAs based superconductors | The recently discovered high-temperature superconductivity in doped
quaternary iron oxypnictides correlates experimentally with a magnetic
instability. We have used first-principles calculations to determine a magnetic
phase diagram of ReO$_{1-\delta}$FeAs (Re=La--Dy) as a function of the doping
$\delta$, of the FeAs i... | 0810.3246v1 |
2008-10-18 | Density Functional Study of Excess Fe in Fe$_{1+x}$Te: Magnetism and Doping | The electronic and magnetic properties of the excess Fe in iron telluride
Fe$_{(1+x)}$Te are investigated by density functional calculations. We find
that the excess Fe occurs with valence near Fe$^{+}$, and therefore provides
electron doping with approximately one carrier per Fe, and furthermore that the
excess Fe is ... | 0810.3274v1 |
2008-10-29 | FeTe as a candidate material for new iron-based superconductor | Tetragonal FeSe is a superconductor with a transition temperature Tc of 8 K
and shows a huge enhancement of Tc with applying pressure. Tetragonal FeTe has
a structure very analogous to superconducting FeSe, but does not show
superconducting transition. We investigated the pressure effect of resistivity
on FeTe. The res... | 0810.5191v1 |
2008-11-08 | Theory of Magnetic Order in $ Fe_{1+y}Te_{1-x}Se_x$ | We develop a local spin model to explain the rich magnetic structures in the
iron-based superconductors $Fe_{1+y}Te_{1-x}Se_x$. We show that our model
exhibits both commensurate antiferromagnetic and incommensurate magnetic order
along the crystal a-axis. The transition from the commensurate to the
incommensurate phase... | 0811.1294v1 |
2008-11-26 | Spin-Valve Effect of the Spin Accumulation Resistance in a Double Ferromagnet - Superconductor Junction | We have measured the transport properties of Ferromagnet - Superconductor
nanostructures, where two superconducting aluminum (Al) electrodes are
connected through two ferromagnetic iron (Fe) ellipsoids in parallel. We find
that, below the superconducting critical temperature of Al, the resistance
depends on the relativ... | 0811.4252v2 |
2008-11-28 | Crystalline multilayers of the confined Yukawa system | The phase diagram of Yukawa particles confined between two parallel hard
walls is calculated at zero-temperature beyond the bilayer regime by
lattice-sum-minimization. Tuning the screening, a rich phase behavior is found
in the regime bounded by stable two-triangular layers and 3-square layers. In
this regime, alternat... | 0811.4763v2 |
2008-12-03 | Relationship between the magnetic hyperfine field and the magnetic moment | Based on experimental data it is shown, for some chosen alloys and compounds
of iron, that there is no one unique relationship between the 57Fe-site
magnetic hyperfine field, Bhf, and the magnetic moment per Fe atom, m. Instead,
the Bhf-m plot consists of several branches, each of them being characteristic
of a given a... | 0812.0671v1 |
2008-12-05 | In-gap bound states and tunneling conductance of multiband superconductors through a normal/superconductor/superconductor junction | The tunneling conductance between a metal and a multiband s-wave
superconductor with a thin layer of single-band s-wave superconductor
sandwiched in between is examined in this paper. We show that an in-gap peak in
conductance curve is found as a result of the formation of in-gap bound state
between the single-band and... | 0812.1068v2 |
2008-12-12 | Physics Potential of Future Atmospheric Neutrino Searches | The potential of future high statistics atmospheric neutrino experiments is
considered, having in mind currently discussed huge detectors of various
technologies (water Cerekov, magnetized iron, liquid Argon). I focus on the
possibility to use atmospheric data to determine the octant of $\theta_{23}$
and the neutrino m... | 0812.2392v1 |
2008-12-12 | Interplay between magnetism and superconductivity in Fe-pnictides | We consider phase transitions and potential co-existence of spin-density-wave
(SDW) magnetic order and extended s-wave ($s^+$) superconducting order within a
two-band itinerant model of iron pnictides, in which SDW magnetism and $s^+$
superconductivity are competing orders. We show that depending on parameters,
the tra... | 0812.2469v1 |
2008-12-22 | The calculation of the effective interaction parameter in LDA+U method by linear response approach for Fe(OH)2 | In this paper we have investigated the electronic properties of Fe(OH)2
hydroxide by using the LSDA+U as well as the generalized gradient
approximation. Our calculations for the iron-hydroxide show that the LSDA
results are greatly at variance with experimental findings. On the other hand
we have shown that LSDA+U is c... | 0812.4116v1 |
2008-12-30 | Maxwell Tension Supports the Water Bridge | A cylindrical flexible cable made up of pure fluid water can be
experimentally spanned across a spatial gap with cable endpoints fixed to the
top edges of two glass beakers. The cable has been called a water bridge in
close analogy to iron cables employed to build ordinary span bridges. A
necessary condition for the co... | 0812.4845v1 |
2009-01-11 | A Possible Theoretical Model For Studying Superconductivity In Fe-based Systems | A theoretical approach with a microscopic model is proposed for the observed
"high temperature superconductivity" in the Iron-based compounds. The above
scheme takes into account two important aspects viz. (i) superconducting
transition close to magnetic ordering and (ii) the layered structure. From the
calculation of ... | 0901.1438v1 |
2009-02-09 | Dislocation Core Energies and Core Fields from First Principles | Ab initio calculations in bcc iron show that a <111> screw dislocation
induces a short-range dilatation field in addition to the Volterra elastic
field. This core field is modeled in anisotropic elastic theory using force
dipoles. The elastic modeling thus better reproduces the atom displacements
observed in ab initio ... | 0902.1451v1 |
2009-02-21 | Unconventional Pairing in Doped Band Insulators on a Honeycomb Lattice : the Role of the Disconnected Fermi Surface and a Possible Application to Superconducting $β$-MNCl (M=Hf,Zr) | We investigate the possibility of realizing unconventional superconductivity
in doped band insulators on the square lattice and the honeycomb lattice, where
the latter is found to be a good candidate due to the disconnectivity of the
Fermi surface. We propose applying the theory to the superconductivity in doped
layere... | 0902.3695v1 |
2009-03-02 | Fermi surface shrinking and interband coupling in iron-based pnictides | Recent measurements of Fermi surface with de Haas-van Alphen oscillations in
LaFePO showed a shrinking of the Fermi pockets with respect to first-principle
LDA calculations, suggesting an energy shift of the hole and electrons bands
with respect to LDA. We show that these shifts are a natural consequence of the
strong ... | 0903.0315v2 |
2009-03-08 | Predictions of highest Transition-temperature for electron-phonon superconductors | Using the Eliashberg strong coupling theory with vertex correction, we
calculate maps of transition temperatures (T$_{c}$) of electron-phonon
superconductors in full parameter space. The maximums of transition
temperatures for superconductors are predicted based on the maps and the
criterion of instability of supercond... | 0903.1395v1 |
2009-03-18 | Piezonuclear neutrons from fracturing of inert solids | Neutron emission measurements by means of helium-3 neutron detectors were
performed on solid test specimens during crushing failure. The materials used
were marble and granite, selected in that they present a different behaviour in
compression failure (i.e., a different brittleness index) and a different iron
content. ... | 0903.3104v1 |
2009-03-26 | SCES '08 - concluding remarks | This year's SCES has proved exciting in the array of unconventional phenomena
discovered both in novel systems, and by the renewed investigation of age-old
systems, arguably in the vicinity of QCPs. From heavy fermion systems, to
cuprate superconductors, and in a new twist iron pnictide superconductors -
some questions... | 0903.4548v1 |
2009-04-05 | Destruction of graphene by metal adatoms | The formation energies for mono- and bivacancies in graphene in the presence
of adatoms of various metals and small metallic clusters have been calculated.
It is shown that transition metal impurities, such as iron, nickel and,
especially, cobalt reduce dramatically the vacancy formation energies whereas
gold impuritie... | 0904.0807v2 |
2009-04-30 | Preparation and superconductivity of iron selenide thin films | FeSex (x = 0.80, 0.84, 0.88, 0.92) thin films were prepared on SrTiO3(001)
(STO), (La,Sr)(Al,Ta)O3(001) (LSAT), and LaAlO3(001) (LAO) substrates by pulsed
laser deposition method. All thin films show single-phase and c-axis oriented
epitaxial growth, and are superconducting. Among them, the FeSe0.88 thin films
show Tc,... | 0904.4731v1 |
2009-05-02 | Quantum fluctuation and geometrical frustration effects on electric polarization | We examine theoretically a possibility of ferroelectricity caused by
electronic charge order without inversion symmetry, motivated by layered iron
oxides. Quantum electronic models in a paired-triangular lattice are analyzed
by utilizing the variational Monte Carlo simulation. Our calculation
demonstrates that combined... | 0905.0182v1 |
2009-05-04 | Berry Phase Coupling and the Cuprate Neutron Scattering Resonance | We examine the influence of coupling between particle-hole and
particle-particle spin fluctuations on the inelastic neutron scattering
resonance (INSR) in cuprate superconductors in both weak and strong interaction
limits. For weak-interactions in the particle-hole channel, we find that the
interchannel coupling can el... | 0905.0464v1 |
2009-05-12 | Magnetic vortex as a ground state for sub-micron antiferromagnetic particles | For submicron particles shaped as any axisymmetric body and made with
standard canted antiferromagnet like hematite or iron borate, the ground state
may comprise of a magnetic vortex with topologically non-trivial distribution
of the sublattice magnetization $\vec{l}$ and planar coreless vortex-like
structure for the n... | 0905.1966v2 |
2009-05-24 | Magnetic impurities in the two-band $s_\pm$-wave superconductors | We investigate the effects of magnetic impurities in a superconducting state
with $s_\pm$ pairing symmetry. Within a two-band model, we find that the
intra-band magnetic scattering serves as a pair breaker while the inter-band
magnetic scattering preserves pairing and hardly affects transition temperature
in the Born l... | 0905.3883v2 |
2009-05-25 | Electron Spin Resonance investigation of undoped and Li-doped CdWO_4 scintillator crystals | Electron spin resonance (ESR) spectra of Fe3+ and Mn2+ ions have been studied
in the nominally pure and 0.05% Li-doped single crystals of CdWO4. The
zero-field splitting parameters are determined with a high precision for both
of the impurities. The result suggest that the Li-doping leads to the increase
of the ionic c... | 0905.4011v1 |
2009-06-02 | Enhancement of Critical Current Densities in Co-Doped BaFe$_{2}$As$_{2}$ with Columnar Defects Introduced by Heavy-Ion Irradiation | We report the first realization of columnar defects in Co-doped
BaFe$_{2}$As$_{2}$ single crystals by heavy-iron irradiation. The columnar
defects are confirmed by transmission electron microscopy and their density is
about 40 % of the irradiation dose. Magneto-optical imaging and bulk
magnetization measurements reveal... | 0906.0444v1 |
2009-06-14 | The Radial Dependence of Temperature and Iron Abundance: Galaxy Clusters from z=0.14 to z=0.89 | Using archival Chandra and XMM-Newton data on 35 galaxy clusters, we measured
average temperature and metallicity profiles for clusters based separated by
temperature, cooling time, and redshift. Our results show no evidence for
significant changes in the metallicity or temperature profiles with redshift
once these sel... | 0906.2564v1 |
2009-06-22 | Kondo resonance narrowing in d- and f-electron systems | By developing a simple scaling theory for the effect of Hund's interactions
on the Kondo effect, we show how an exponential narrowing of the Kondo
resonance develops in magnetic ions with large Hund's interaction. Our theory
predicts an exponential reduction of the Kondo temperature with spin S of the
Hund's coupled mo... | 0906.4107v1 |
2009-06-29 | Elastic energy of a straight dislocation and contribution from core tractions | We derive an expression of the core traction contribution to the dislocation
elastic energy within linear anisotropic elasticity theory using the sextic
formalism. With this contribution, the elastic energy is a state variable
consistent with the work of the Peach-Koehler forces. This contribution needs
also to be cons... | 0906.5332v1 |
2009-07-15 | Perfect and partial hedging for swing game options in discrete time | The paper introduces and studies hedging for game (Israeli) style extension
of swing options considered as multiple exercise derivatives. Assuming that the
underlying security can be traded without restrictions we derive a formula for
valuation of multiple exercise options via classical hedging arguments.
Introducing t... | 0907.2541v1 |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.