publicationDate stringlengths 1 2.79k | title stringlengths 1 36.5k ⌀ | abstract stringlengths 1 37.3k ⌀ | id stringlengths 9 47 |
|---|---|---|---|
2015-06-18 | Robustness of s-wave pairing symmetry in iron-based superconductors and its implications to fundamentals on magnetically-driven high temperature superconductivity | Under the assumption that the superconducting state belongs to a single
irreducible representation of lattice symmetry, we argue that the pairing
symmetry in all measured iron-based superconductors is universally consistent
with the A_{1g} s-wave. The robust s-wave pairing throughout the different
families of iron-base... | 1506.05791v1 |
2015-07-07 | SD 1313-0019 -- Another second-generation star with [Fe/H] = -5.0, observed with the Magellan Telescope | We present a Magellan/MIKE high-resolution (R ~ 35,000) spectrum of the
ancient star SD 1313-0019 which has an iron abundance of [Fe/H] = -5.0, paired
with a carbon enhancement of [C/Fe] ~ 3.0. The star was initially identified by
Allende Prieto et al. in the BOSS survey. Its medium-resolution spectrum
suggested a high... | 1507.01973v2 |
2015-07-15 | Impact of Uniaxial Pressure on Structural and Magnetic Phase Transitions in Electron-Doped Iron Pnictides | We use neutron resonance spin echo and Larmor diffraction to study the effect
of uniaxial pressure on the tetragonal-to-orthorhombic structural ($T_s$) and
antiferromagnetic (AF) phase transitions in iron pnictides
BaFe$_{2-x}$Ni$_{x}$As$_{2}$ ($x=0,0.03,0.12$), SrFe$_{1.97}$Ni$_{0.03}$As$_2$,
and BaFe$_2$(As$_{0.7}$P$... | 1507.04191v2 |
2015-08-24 | Critical current density and microstructure of iron sheathed multifilamentary Sr1-xKxFe2As2/Ag composite conductors | Iron-based superconductors have been considered to be very promising in
high-field applications, for which multifilamentary wire and tape conductors
with high mechanical strength are essential. In this work, 7-,19- and
114-filament Sr0.6K0.4Fe2As2 (Sr-122) superconducting wires and tapes with
silver as matrix and iron ... | 1508.05781v1 |
2015-09-29 | Chemical analysis of Asymptotic Giant Branch stars in M62 | We have collected UVES-FLAMES high-resolution spectra for a sample of 6
asymptotic giant branch (AGB) and 13 red giant branch (RGB) stars in the
Galactic globular cluster M62 (NGC6266). Here we present the detailed abundance
analysis of iron, titanium, and light-elements (O, Na, Al and Mg). For the
majority (5 out 6) o... | 1509.08917v1 |
2015-11-08 | Magnetic ground state of FeSe | Elucidating the nature of the magnetism of a high-temperature superconductor
is crucial for establishing its pairing mechanism. The parent compounds of the
cuprate and iron-pnictide superconductors exhibit N\'eel and stripe magnetic
order, respectively. However, FeSe, the structurally simplest iron-based
superconductor... | 1511.02485v2 |
2015-11-13 | Spin nematic susceptibility studied by inelastic neutron scattering in FeSe | Mechanism of unconventional superconductivity in FeSe has been intensely
scrutinized recently because of a variety of exotic properties unprecedented
for other iron-based superconductors. A central unanswered question concerns
the origin of the interaction that causes the nematic transition at $T_s=90\,K$
without accom... | 1511.04267v4 |
2015-12-08 | Interface control by homoepitaxial growth in pulsed laser deposited iron chalcogenide thin ilms | Thin film growth of iron chalcogenides by pulsed laser deposition (PLD) is
still a delicate issue in terms of simultaneous control of stoichiometry,
texture, substrate/film interface properties, and superconducting properties.
The high volatility of the constituents sharply limits optimal deposition
temperatures to a n... | 1512.02524v1 |
2015-12-19 | What makes the Tc of monolayer FeSe on SrTiO3 so high: a sign-problem-free quantum Monte Carlo study | Monolayer FeSe films grown on SrTiO3 (STO) substrate show superconducting
gap-opening temperatures (Tc) which are almost an order of magnitude higher
than those of the bulk FeSe and are highest among all known Fe-based
superconductors. Angle-resolved photoemission spectroscopy (ARPES) observed
"replica bands" suggestin... | 1512.06179v4 |
2016-01-11 | High-temperature superconductivity from fine-tuning of Fermi-surface singularities in iron oxypnictides | In the family of the iron-based superconductors, the $RE$FeAsO-type compounds
(with $RE$ being a rare-earth metal) exhibit the highest bulk superconducting
transition temperatures ($T_{\mathrm{c}}$) up to $55\ \textrm{K}$ and thus hold
the key to the elusive pairing mechanism. Recently, it has been demonstrated
that th... | 1601.02686v1 |
2016-01-20 | Orbital Order and Spin Nematicity in the Tetragonal Phase of Electron-doped Iron-Pnictides NaFe$_{1-x}$Co$_{x}$As | In copper-oxide and iron-based high temperature (high-$T_{\rm c}$)
superconductors, many physical properties exhibit in-plane anisotropy, which is
believed to be caused by a rotational symmetry-breaking nematic order, whose
origin and its relationship to superconductivity remain elusive. In many
iron-pnictides, a tetra... | 1601.05293v1 |
2016-01-29 | Weak-coupling superconductivity in a strongly correlated iron pnictide | Iron-based superconductors have been found to exhibit an intimate interplay
of orbital, spin, and lattice degrees of freedom, dramatically affecting their
low-energy electronic properties, including superconductivity. Albeit the
precise pairing mechanism remains unidentified, several candidate interactions
have been su... | 1601.08195v1 |
2016-02-16 | Surface terminations and layer-resolved spectroscopy in 122 iron pnictide superconductors | The surface terminations of 122-type alkaline earth metal iron pnictides
AEFe2As2 (AE = Ca, Ba) are investigated with scanning tunneling
microscopy/spectroscopy (STM/STS). Cleaving these crystals at a cryogenic
temperature yields a large majority of terminations with atomically resolved
square-root-two (rt2) or 1*2 lat... | 1602.04937v1 |
2016-02-25 | ARPES view of orbitally resolved quasiparticle lifetimes in iron pnictides | We study with ARPES the renormalization and quasiparticle lifetimes of the
$d_{xy}$ and $d_{xz}$/$d_{yz}$ orbitals in two iron pnictides, LiFeAs and
Ba(Fe$_{0.92}$Co$_{0.08}$)$_2$As$_2$ (Co8). We find that both quantities depend
on orbital character rather than on the position on the Fermi Surface (for
example hole or ... | 1602.07986v1 |
2016-03-07 | The intercalation chemistry of layered iron chalcogenide superconductors | The iron chalcogenides FeSe and FeS are superconductors composed of
two-dimensional sheets held together by van der Waals interactions, which makes
them prime candidates for the intercalation of various guest species. We review
the intercalation chemistry of FeSe and FeS superconductors and discuss their
synthesis, str... | 1603.02334v1 |
2016-03-15 | Iron in galaxy groups and clusters: Confronting galaxy evolution models with a newly homogenised dataset | We present an analysis of the iron abundance in the hot gas surrounding
galaxy groups and clusters. To do this, we first compile and homogenise a large
dataset of 79 low-redshift (|z| = 0.03) systems (159 individual measurements)
from the literature. Our analysis accounts for differences in aperture size,
solar abundan... | 1603.04858v1 |
2016-03-16 | Tracing the electronic pairing glue in unconventional superconductors via inelastic Scanning Tunneling Spectroscopy | The origin of Cooper pairing in high-temperature superconductors, such as the
copper-oxide and iron-based system, is still under debate. High transition
temperatures together with unconventional pairing states support the picture of
an electronic pairing glue in the cuprates, where superconductivity is mediated
by coll... | 1603.05288v3 |
2016-04-26 | Surface Nematic Order in Iron Pnictides | Electronic nematicity plays important role in iron-based superconductors.
These materials have layered structure and theoretical description of their
magnetic and nematic transitions has been well established in two-dimensional
approximation, i.e., when the layers can be treated independently. However, the
interaction ... | 1604.07757v3 |
2016-05-28 | Hubbard interactions in iron-based pnictides and chalcogenides: Slater parametrization, screening channels and frequency dependence | We calculate the strength of the frequency-dependent on-site electronic
interactions in the iron pnictides LaFeAsO, BaFe2As2, BaRu2As2, and LiFeAs and
the chalcogenide FeSe from first principles within the constrained random phase
approximation. We discuss the accuracy of an atomic-like parametrization of the
two-index... | 1605.08918v1 |
2016-06-15 | Iron K$α$ line of Kerr black holes with scalar hair | Recently, a family of hairy black holes in 4-dimensional Einstein gravity
minimally coupled to a complex, massive scalar field was discovered~\cite{hbh}.
Besides the mass $M$ and spin angular momentum $J$, these objects are
characterized by a Noether charge $Q$, measuring the amount of scalar hair,
which is not associa... | 1606.04654v2 |
2016-07-05 | Two new parent compounds for FeSe-based superconducting phases | It is well established that the occurrence of superconductivity in iron
pnictides is closely related to the tetragonal to orthorhombic structural and
antiferromagnetic (AFM) phase transitions. It, however, has not been clear
whether the same scenario is appropriate for iron chalcogenide counterparts due
to the absence ... | 1607.01103v1 |
2016-07-11 | Effect of local environment on moment formation in iron silicides | The effect of local environment on the formation of magnetic moments on Fe
atoms in iron silicides are studied by combination of ab initio and model
calculations. The suggested model includes all Fe d- and Si p-orbitals,
intra-atomic Coulomb interactions, inter-atomic Fe-Fe exchange and hopping of
electrons to nearest ... | 1607.02856v2 |
2016-07-12 | Simulation study of the correlation ($X_{max}^μ$, $N^μ$) in view of obtaining information on primary mass of the UHECRs | In this paper we study, using Monte Carlo simulations, the possibility to
discriminate the mass of the Ultra High Energy Cosmic Rays (UHECRs) by
combining information obtained from the maximum $X_{max}^{\mu}$ of the muon
production rate longitudinal profile of Extensive Air Showers (EAS) and the
number of muons, $N^{\m... | 1607.03244v1 |
2016-07-17 | Testing the Kerr metric with the iron line and the KRZ parametrization | The spacetime geometry around astrophysical black holes is supposed to be
well approximated by the Kerr metric, but deviations from the Kerr solution are
predicted in a number of scenarios involving new physics. Broad iron K$\alpha$
lines are commonly observed in the X-ray spectrum of black holes and originate
by X-ray... | 1607.04893v2 |
2016-08-19 | Optical observation of spin-density-wave fluctuations in Ba122 iron-based superconductors | In iron-based superconductors, a spin-density-wave (SDW) magnetic order is
suppressed with doping and unconventional superconductivity appears in close
proximity to the SDW instability. The optical response of the SDW order shows
clear gap features: substantial suppression in the low-frequency optical
conductivity, alo... | 1608.05474v1 |
2016-08-23 | Non-LTE line formation of Fe in late-type stars - III. 3D non-LTE analysis of metal-poor stars | As one of the most important elements in astronomy, iron abundance
determinations need to be as accurate as possible. We investigate the accuracy
of spectroscopic iron abundance analyses using archetypal metal-poor stars. We
perform detailed 3D non-LTE radiative transfer calculations based on 3D
hydrodynamic Stagger mo... | 1608.06390v2 |
2016-09-04 | Iron K$α$ line of boson stars | The present paper is a sequel to our previous work [Y. Ni et al., JCAP 1607,
049 (2016)] in which we studied the iron K$\alpha$ line expected in the
reflection spectrum of Kerr black holes with scalar hair. These metrics are
solutions of Einstein's gravity minimally coupled to a massive, complex scalar
field. They form... | 1609.00901v2 |
2016-10-13 | TOPoS: III. An ultra iron-poor multiple CEMP system | One of the primary objectives of the TOPoS survey is to search for the most
metal-poor stars. Our search has led to the discovery of one of the most
iron-poor objects known, SDSS\,J092912.32+023817.0. This object is a multiple
system, in which two components are clearly detected in the spectrum. We have
analysed 16 hig... | 1610.04106v1 |
2016-11-01 | Experimental evidence for the importance of Hund's exchange interaction for the incoherence of the charge carriers in iron-based superconductors | Angle-resolved photoemission spectroscopy (ARPES) is used to study the
scattering rates of charge carriers from the hole pockets near Gamma in the
iron-based high-Tc hole doped superconductors KxBa1-xFe2As2 x=0.4 and
KxEu1-xFe2As2 x=0.55$ and the electron doped compound Ba(Fe1-xCox)2As2 x=0.075.
The scattering rate for... | 1611.00239v1 |
2016-11-10 | A new migration mechanism for oversized solutes in cubic lattices: correlation effects | Recent ab-initio calculations showed that oversized solute atoms (OSA) in BCC
and FCC iron exhibit a very strong attraction with a nearby vacancy (V) at
first neighbour distance (1NN). The attraction it is so large that the 1NN pair
OSA+V is no longer stable and relaxes spontaneously towards a new configuration
where t... | 1611.03230v2 |
2016-11-10 | Lattice Parameters Guide Superconductivity in Iron-Arsenides | The discovery of superconducting materials has led to their use in
technological marvels such as magnetic-field sensors in MRI machines, powerful
research magnets, short transmission cables, and high-speed trains. Despite
such applications, the uses of superconductors are not widespread because they
function much below... | 1611.03400v1 |
2016-12-01 | Spin anisotropy due to spin-orbit coupling in optimally hole-doped Ba$_{0.67}$K$_{0.33}$Fe$_{2}$As$_{2}$ | We use polarized inelastic neutron scattering to study the temperature and
energy dependence of spin space anisotropies in the optimally hole-doped iron
pnictide Ba$_{0.67}$K$_{0.33}$Fe$_{2}$As$_{2}$ ($T_{{\rm c}}=38$ K). In the
superconducting state, while the high-energy part of the magnetic spectrum is
nearly isotro... | 1612.00379v2 |
2016-12-22 | Unravelling incommensurate magnetism and its emergence in iron-based superconductors | We focus on a broad class of tetragonal itinerant systems sharing a tendency
towards the spontaneous formation of incommensurate magnetism with ordering
wavevectors $\mathbf{Q}_{1,2}=(\pi-\delta,0)/(0,\pi-\delta)$ or
$\mathbf{Q}_{1,2}=(\pi,\delta)/(-\delta,\pi)$. Employing a Landau approach, we
obtain the generic magne... | 1612.07633v3 |
2017-01-04 | Origin of the Galactic Diffuse X-ray Emission: Iron K-shell Line Diagnostics | This paper reports detailed K-shell line profiles of iron (Fe) and nickel
(Ni) of the Galactic Center X-ray Emission (GCXE), Galactic Bulge X-ray
Emission (GBXE), Galactic Ridge X-ray Emission (GRXE), magnetic Cataclysmic
Variables (mCVs), non-magnetic Cataclysmic Variables (non-mCVs), and coronally
Active Binaries (AB... | 1701.00884v1 |
2017-02-07 | Supernova of 1006 (G327.6+14.6) | SN 1006 (G327.6+14.6) was the brightest supernova (SN) witnessed in human
history. As of one thousand years later, it stands out as an ideal laboratory
to study Type Ia SNe and shocks in supernova remnants (SNRs). The present state
of knowledge about SN 1006 is reviewed in this article. No star consistent with
a surviv... | 1702.02054v1 |
2017-02-13 | Electron-Capture and Low-Mass Iron-Core-Collapse Supernovae: New Neutrino-Radiation-Hydrodynamics Simulations | We present new 1D (spherical) and 2D (axisymmetric) simulations of
electron-capture (EC) and low-mass iron-core-collapse supernovae (SN). We
consider six progenitor models: the ECSN progenitor from Nomoto (1984, 1987);
two ECSN-like low-mass low-metallicity iron core progenitors from Heger
(private communication); and ... | 1702.03927v2 |
2017-02-25 | Serum protein resistant behavior of multisite-bound poly(ethylene glycol) chains onto iron oxide surfaces | Recent surveys have shown that the number of nanoparticle-based formulations
actually used at the clinical level is significantly lower than expected a
decade ago. One reason for this is that the nanoparticle physicochemical
properties fall short for handling the complexity of biological environments
and for preventing... | 1702.07857v1 |
2017-03-11 | Non-LTE line formation of Fe in late-type stars IV: Modelling of the solar centre-to-limb variation in 3D | Our ability to model the shapes and strengths of iron lines in the solar
spectrum is a critical test of the accuracy of the solar iron abundance, which
sets the absolute zero-point of all stellar metallicities. We use an extensive
463-level Fe atom with new photoionisation cross-sections for FeI as well as
quantum mech... | 1703.04027v1 |
2017-03-25 | Electronic structure of FeS | Here we report the electronic structure of FeS, a recently identified
iron-based superconductor. Our high-resolution angle-resolved photoemission
spectroscopy studies show two hole-like ($\alpha$ and $\beta$) and two
electron-like ($\eta$ and $\delta$) Fermi pockets around the Brillouin zone
center and corner, respecti... | 1703.08682v1 |
2017-04-03 | Nucleosynthesis in thermonuclear supernovae | The explosion energy of thermonuclear (Type Ia) supernovae is derived from
the difference in nuclear binding energy liberated in the explosive fusion of
light 'fuel' nuclei, predominantly carbon and oxygen, into more tightly bound
nuclear 'ash' dominated by iron and silicon group elements. The very same
explosive therm... | 1704.00415v1 |
2017-04-07 | High Radiation Pressure on Interstellar Dust Computed by Light-Scattering Simulation on Fluffy Agglomerates of Magnesium-silicate Grains with Metallic-iron Inclusions | Recent space missions have provided information on the physical and chemical
properties of interstellar grains such as the ratio $\beta$ of radiation
pressure to gravity acting on the grains in addition to the composition,
structure, and size distribution of the grains. Numerical simulation on the
trajectories of inter... | 1704.02066v2 |
2017-05-05 | X-ray Magnetic and Natural Circular Dichroism from first principles: Calculation of K- and L1-edge spectra | An efficient first principles approach to calculate X-ray magnetic circular
dichroism (XMCD) and X-ray natural circular dichroism (XNCD) is developed and
applied in the near edge region at the K-and L1-edges in solids. Computation of
circular dichroism requires precise calculations of X-ray absorption spectra
(XAS) for... | 1705.02192v1 |
2017-05-05 | Constraining The Single-Degenerate Channel of Type Ia Supernovae With Stable Iron-Group Elements in SNR 3C 397 | Recent Suzaku X-ray spectra of SNR 3C 397 indicate enhanced stable iron-group
element abundances of Ni, Mn, Cr, and Fe. Seeking to address key questions
about the progenitor and explosion mechanism of 3C 397, we compute
nucleosynthetic yields from a suite of multidimensional hydrodynamics models in
the near-Chandrasekh... | 1705.02339v1 |
2017-05-09 | Chemical abundances in the nucleus of the Sagittarius dwarf spheroidal galaxy | We present Iron, Magnesium, Calcium, and Titanium abundances for 235 stars in
the central region of the Sagittarius dwarf spheroidal galaxy (within 9.0
arcmin ~70 pc from the center) from medium-resolution Keck/DEIMOS spectra. All
the considered stars belong to the massive globular cluster M54 or to the
central nucleus... | 1705.03251v1 |
2017-05-12 | Orbital-selective Mott phase in multiorbital models for iron pnictides and chalcogenides | There is increasing recognition that the multiorbital nature of the 3d
electrons is important to the proper description of the electronic states in
the normal state of the iron-based superconductors. Earlier studies of the
pertinent multiorbital Hubbard models identified an orbital-selective Mott
phase, which anchors t... | 1705.04541v1 |
2017-07-04 | Apparent Trend of the Iron Abundance in NGC 3201: the Same Outcome with Different Data | We further study the unusual trend we found at statistically significant
levels in some globular clusters, including NGC 3201: a decreasing iron
abundance in red giants towards the cluster centers. We first show that
recently published new estimates of iron abundance in the cluster reproduce
this trend, in spite of the... | 1707.00786v1 |
2017-07-05 | Switching Magnetism and Superconductivity with Spin-Polarized Current in Iron-Based Superconductor | We have explored a new mechanism for switching magnetism and
superconductivity in a magnetically frustrated iron-based superconductor using
spin-polarized scanning tunneling microscopy (SPSTM). Our SPSTM study on single
crystal Sr$_2$VO$_3$FeAs shows that a spin-polarized tunneling current can
switch the Fe-layer magne... | 1707.01191v2 |
2017-07-10 | Explosive nucleosynthesis of ultra-stripped Type Ic supernovae: application to light trans-iron elements | We investigate the explosive nucleosynthesis during two dimensional
neutrino-driven explosion of ultra-stripped Type Ic supernovae evolved from
1.45 and 1.5 M$_\odot$ CO stars. These supernovae explode with the explosion
energy of $\sim 10^{50}$ erg and release $\sim 0.1$ M$_\odot$ ejecta. The light
trans-iron elements... | 1707.02685v1 |
2017-07-26 | Shock-darkening in ordinary chondrites: determination of the pressure-temperature conditions by shock physics mesoscale modeling | We determined the shock-darkening pressure range in ordinary chondrites using
the iSALE shock physics code. We simulated planar shock waves on a mesoscale in
a sample layer at different nominal pressures. Iron and troilite grains were
resolved in a porous olivine matrix in the sample layer. We used equations of
state (... | 1707.08422v1 |
2017-08-03 | Orbital-selective spin excitation of a magnetic porphyrin | Scattering of electrons by localized spins is the ultimate process enabling
electrical detection and control of the magnetic state of a spin-doped
material. At the molecular scale, this scattering is mediated by the electronic
orbitals hosting the spin. Here we report the selective excitation of a
molecular spin by ele... | 1708.01268v2 |
2017-08-09 | Measurement of the Iron Spectrum in Cosmic Rays with VERITAS | The elemental energy spectra of cosmic rays play an important role in
understanding their acceleration and propagation. Most current results are
obtained either from direct measurements by balloon or satellite detectors, or
from indirect measurements by air shower detector arrays on the Earth's
surface. Imaging Air Che... | 1708.02960v2 |
2017-09-05 | On the Iron Abundance Anomaly in K-dwarf and Hyades Stars | Using standard 1D-LTE model atmosphere analysis, we provide an in-depth
investigation of iron abundance as derived from neutral and singly ionization
iron lines (Fe {\scriptsize{I, II}}) in nearby star clusters. Specifically, we
replicate the discrepancy regarding $\Delta$[Fe/H], wherein the difference of
Fe {\scriptsi... | 1709.01244v1 |
2017-09-21 | Analysis of Ultra High Energy Muons at the INO-ICAL Using Pair-Meter Technique | The proposed ICAL detector at INO is a large sized underground magnetized
iron detector. ICAL is designed to reconstruct muon momentum using magnetic
spectrometers. Energy measurement using magnets fail for muons in TeV range,
since the angular deflection of the muon in the magnetic field is negligible
and the muon tra... | 1709.07445v1 |
2017-10-04 | Pop III $\textit{i}$-process Nucleosynthesis and the Elemental Abundances of SMSS J0313-6708 and the Most Iron-Poor Stars | We have investigated a highly energetic H-ingestion event during shell He
burning leading to H-burning luminosities of $\log(L_\mathrm{H}/\mathrm{\Lsun})
\sim 13$ in a $45 \Msun$ Pop III massive stellar model. In order to track the
nucleosynthesis which may occur in such an event, we run a series of
single-zone nucleos... | 1710.01763v4 |
2017-10-07 | Simulations of Electron Capture and Low-Mass Iron Core Supernovae | The evolutionary pathways of core-collapse supernova progenitors at the
low-mass end of the spectrum are beset with major uncertainties. In recent
years, a variety of evolutionary channels has been discovered in addition to
the classical electron capture supernova channel of super-AGB stars. The few
available progenito... | 1710.02641v1 |
2017-10-24 | Recent advances in iron-based superconductors toward applications | Iron with a large magnetic moment was widely believed to be harmful to the
emergence of superconductivity because of the competition between the static
ordering of electron spins and the dynamic formation of electron pairs (Cooper
pairs). Thus, the discovery of a high critical temperature (Tc) iron-based
superconductor... | 1710.08574v1 |
2017-10-24 | Mössbauer study of Eu0.57Ca0.43Fe2As2 and Eu0.73Ca0.27(Fe0.87Co0.13)2As2: A comparison to 122 iron-based superconductors parent compounds EuFe2As2 and CaFe2As2 | 57Fe and 151Eu Moessbauer spectra were obtained versus temperature for
Eu0.57Ca0.43Fe2As2 compound with 3d and 4f magnetic order and
Eu0.73Ca0.27(Fe0.87Co0.13)2As2 re-entrant superconductor, where the finite
resistivity reappears while approaching the ground state. They were compared
with previously obtained spectra fo... | 1710.08887v3 |
2017-11-01 | Spectroscopic properties of a two-dimensional time-dependent Cepheid model II. Determination of stellar parameters and abundances | Standard spectroscopic analyses of variable stars are based on hydrostatic
one-dimensional model atmospheres. This quasi-static approach has theoretically
not been validated. We aim at investigating the validity of the quasi-static
approximation for Cepheid variables. We focus on the spectroscopic
determination of the ... | 1711.00236v2 |
2017-11-08 | Chemical Study of the Metal-rich Globular Cluster NGC 5927 | Globular Clusters (GCs) are natural laboratories where stellar and chemical
evolution can be studied in detail. In addition, their chemical patterns and
kinematics can tell us wich Galactic structure (Disk, Bulge, Halo or
extragalactic) the cluster belongs to. NGC 5927 is one of most metal-rich GCs
in the Galaxy and it... | 1711.03176v1 |
2017-12-25 | Discovery of 6.4 keV line and soft X-ray emissions from G323.7$-$1.0 with Suzaku | In this paper, the Suzaku X-ray data of the Galactic Supernova Remnant (SNR)
candidate G323.7$-$1.0 are analyzed to search for X-ray emission.
Spatially-extended enhancements in the 6.4 keV line and in soft X-rays are
found inside or on the radio shell. The soft X-ray enhancement would be the
hottest part of the shell-... | 1712.09024v1 |
2018-02-06 | Odd and even modes of neutron spin resonance in the bilayer iron-based superconductor CaKFe$_4$As$_4$ | We report an inelastic neutron scattering study on the spin resonance in the
bilayer iron-based superconductor CaKFe$_4$As$_4$. In contrast to its
quasi-two-dimensional electron structure, three strongly $L$-dependent modes of
spin resonance are found below $T_c=35$ K. The mode energies are below and
linearly scale wit... | 1802.01901v2 |
2018-03-02 | Neutron spin resonance in the 112-type iron-based superconductor | We use inelastic neutron scattering to study the low-energy spin excitations
of 112-type iron pnictide Ca$_{0.82}$La$_{0.18}$Fe$_{0.96}$Ni$_{0.04}$As$_{2}$
with bulk superconductivity below $T_c=22$ K. A two-dimensional spin resonance
mode is found around $E=$ 11 meV, where the resonance energy is almost
temperature in... | 1803.00779v2 |
2018-04-12 | Lateral manipulation with combined atomic force and scanning tunneling microscopy using CO-terminated tips | CO-terminated tips currently provide the best spatial resolution obtainable
in atomic force microscopy. Due to their chemical inertness, they allow to
probe interactions dominated by Pauli repulsion. The small size and inertness
of the oxygen front atom yields unprecedented resolution of organic molecules,
metal cluste... | 1804.04382v3 |
2018-05-03 | Uncertainties in s-process nucleosynthesis in low mass stars determined from Monte Carlo variations | The main s-process taking place in low mass stars produces about half of the
elements heavier than iron. It is therefore very important to determine the
importance and impact of nuclear physics uncertainties on this process. We have
performed extensive nuclear reaction network calculations using individual and
temperat... | 1805.01250v1 |
2018-05-20 | High-pressure effects on isotropic superconductivity in the iron-free layered pnictide superconductor BaPd2As2 | While the layered 122 iron arsenide superconductors are highly anisotropic,
unconventional, and exhibit several forms of electronic orders that coexist or
compete with superconductivity in different regions of their phase diagrams, we
find in the absence of iron in the structure that the superconducting
characteristics... | 1805.07838v1 |
2018-05-24 | Antiferromagnetically assisted electron-phonon coupling and spin-lattice interaction in Fe-based superconductors | We present a theoretical ab-initio approach that allows us to explicitly
calculate the superconducting transition temperatures (Tc) of the iron-based
superconductors of LaFeAsO1-xFx, SmFeAsO1-xFx, NdFeAsO1-xFx, Ba1-xKxFe2As2,
FeSe and LiFeAs that fit perfectly with the experiments. We consider recent
evidence that elec... | 1805.09754v5 |
2018-05-25 | Room Temperature Magnetic Order in Air-Stable Ultra-Thin Iron Oxide | Certain two-dimensional (2D) materials exhibit intriguing properties such as
valley polarization, ferroelectricity, superconductivity and charge-density
waves. Many of these materials can be manually assembled into atomic-scale
multilayer devices under ambient conditions, owing to their exceptional
chemical stability. ... | 1805.10372v1 |
2018-06-21 | A numerical study on the softening process of iron ore particles in the cohesive zone of an experimental blast furnace using a coupled CFD-DEM method | Reduced iron-bearing materials start softening in the cohesive zone of a
blast furnace due to the high temperature and the weight of the burden above.
Softening process causes a reduction of void space between particles. As a
result, the pressure drop and gas flow change remarkably in this particular
zone. As a consequ... | 1806.08114v1 |
2018-07-02 | Time-Variability of equivalent width of 6.4 keV line from the Arches Complex: reflected X-rays or charged particles? | Molecular gas in Arches cloud located near the Arches cluster is one of the
emitters of K-$\alpha$ line of neutral iron and X-ray continuum in the Galactic
center (GC). Similarly to the cloud Sgr B2, another well-known emitter of the
iron line in the GC, the Arches cloud demonstrates temporal decline of the
X-ray emiss... | 1807.00526v1 |
2018-07-24 | Orbital selectivity versus Pomeranchuk instability in the iron-chalcogenide superconductors: A two-loop renormalization group study | We perform a two-loop renormalization group (RG) analysis of a 2D effective
multiband model, which is relevant for describing the low-energy properties of
some iron-chalcogenide superconducting materials. Crucial ingredients in this
analysis are the calculation of higher-order contributions in the RG scheme
that go bey... | 1807.09007v2 |
2018-08-09 | Blocking of iron magnetic moments and Spin density wave in FeTi2S4 and Fe2TiS4 | Iron-titanium sulfides FeTi2S4 and Fe2TiS4 have been structurally and
magnetically characterized using powder X Ray Diffraction with Rietveld
refinement method and 57Fe M\"ossbauer spectroscopy at variable temperature.
Both sulfides have the same crystallographic phase, based on the monoclinic
Cr3S4 type structure and ... | 1808.03362v1 |
2018-08-22 | Coexistence of ferromagnetic and stripe-type antiferromagnetic spin fluctuations in YFe$_2$Ge$_2$ | We report neutron scattering measurements of single-crystalline YFe$_2$Ge$_2$
in the normal state, which has the same crystal structure to the 122 family of
iron pnictide superconductors. YFe$_2$Ge$_2$ does not exhibit long range
magnetic order, but exhibits strong spin fluctuations. Like the iron pnictides,
YFe$_2$Ge$... | 1808.07262v1 |
2018-08-26 | Phase transition in CaFeAsH: bridging 1111 and 122 iron-based superconductors | Iron-based superconductors can be categorized as two types of parent
compounds by considering the nature of their temperature-induced phase
transitions; namely, first order transitions for 122- and 11-type compounds and
second-order transitions for 1111-type compounds. This work examines the
structural and magnetic tra... | 1808.08564v1 |
2018-09-23 | Electronic structure and spin dynamics of ACo2As2 (A=Ba, Sr, Ca) | The electronic structures, charge and spin dynamics of the cobalt pnictide
compounds ACo2As2 (A=Ba, Sr, Ca) in the paramagnetic state are investigated by
using density functional theory combined with dynamical mean-field theory. In
contrast to their iron counterparts, these cobalt pnictide compounds have
three-dimensio... | 1809.08550v1 |
2018-10-15 | The Limited Contribution of Low- and High-Luminosity Gamma-Ray Bursts to Ultra-High Energy Cosmic Rays | The acceleration site for ultra-high energy cosmic rays (UHECR) is still an
open question despite extended research. In this paper, we reconsider the
prompt phase of gamma-ray bursts (GRBs) as a possible candidate for this
acceleration and constrain the maximum proton energy in optically thin
synchrotron and photospher... | 1810.06579v2 |
2018-10-24 | Simulation of the electromagnetic wall response during Vertical Displacement Events (VDE) in ITER tokamak | The key basis for tokamak plasma disruption modeling is to understand how
currents flow to the plasma facing surfaces during plasma disruption events. In
ITER tokamak, the occurrence of a limited number of major disruptions will
definitively damage the chamber with no possibility to restore the device. In
the current e... | 1810.10277v1 |
2018-11-07 | Stabilizing spin systems via symmetrically tailored RKKY interactions | The spin of a single atom adsorbed on a substrate is a promising building
block for future spintronics and quantum computation schemes. To process spin
information and also for increased magnetic stability, these building blocks
have to be coupled. For a single atom, a high symmetry of the environment is
known to lead ... | 1811.02807v1 |
2018-11-20 | Topological Fermi-arc surface resonances in bcc iron | The topological classification of matter has been extended to include
semimetallic phases characterized by the presence of topologically protected
band degeneracies. In Weyl semimetals, the foundational gapless topological
phase, chiral degeneracies are isolated near the Fermi level and give rise to
the Fermi-arc surfa... | 1811.08178v1 |
2018-12-07 | Optimal Dynamic Auctions are Virtual Welfare Maximizers | We are interested in the setting where a seller sells sequentially arriving
items, one per period, via a dynamic auction. At the beginning of each period,
each buyer draws a private valuation for the item to be sold in that period and
this valuation is independent across buyers and periods. The auction can be
dynamic i... | 1812.02993v1 |
2018-12-14 | Multitude of iron lines including a Compton scattered component in OAO 1657--415 detected with Chandra | We present a high resolution X-ray spectrum of the accreting X-ray pulsar,
OAO 1657--415 with HETG+ACIS-S onboard \emph{Chandra},revealing the presence of
a broad line component around $\sim$ 6.3 keV associated with the neutral iron
K$_\alpha$ line at 6.4 \rm{keV}. This is interpreted as Compton shoulder
arising from t... | 1812.06108v1 |
2018-12-20 | Storing magnetic fields in pre-collapse cores of massive stars | We argue that the radiative zone above the iron core in pre-collapse cores of
massive stars can store strong magnetic fields. To reach this conclusion we use
the stellar evolutionary code MESA to simulate the evolution of two stellar
models with initial masses of 15Mo and 25Mo, and reveal the entropy profile
above the ... | 1812.08518v2 |
2019-01-31 | Intertwined magnetic and nematic orders in semiconducting KFe$_{0.8}$Ag$_{1.2}$Te$_2$ | Superconductivity in the iron pnictides emerges from metallic parent
compounds exhibiting intertwined stripe-type magnetic order and nematic order,
with itinerant electrons suggested to be essential for both. Here we use X-ray
and neutron scattering to show that a similar intertwined state is realized in
semiconducting... | 1901.11206v1 |
2019-02-18 | The antiferromagnetic and phonon-mediated model of the NaFeAs, LiFeAs and FeSe superconductors | Recently it has been suggested that the role of electron-phonon coupling in
the mechanism of iron-based superconductors may have been underestimated and
that the antiferromagnetism and the induced xy potential may even have a
dramatic amplification effect on electron-phonon coupling. To substantiate the
recently announ... | 1902.06463v4 |
2019-02-18 | On the iron ionization balance of cool stars | High-resolution spectroscopic studies of solar-type stars have revealed
higher iron abundances derived from singly ionized species compared to neutral,
violating the ionization equilibrium under the assumption of local
thermodynamic equilibrium. In this work, we investigate the overabundances of
FeII lines reported in ... | 1902.06769v1 |
2019-02-27 | Intertwined spin-orbital coupled orders in the iron-based superconductors | The underdoped phase diagram of the iron-based superconductors exemplifies
the complexity common to many correlated materials. Indeed, multiple ordered
states that break different symmetries but display comparable transition
temperatures are present. Here, we argue that such a complexity can be
understood within a simp... | 1902.10831v2 |
2019-03-08 | Local Superconductivity in Vanadium Iron Arsenide | We investigate the chemical substitution of group 5 into BaFe2As2 (122) iron
arsenide, in the effort to understand why Fe-site hole doping of this compound
(e.g., using group 5 or 6) does not yield bulk superconductivity. We find an
increase in c-lattice parameter of the BaFe2As2 with the substitution of V, Nb,
or Ta; ... | 1903.03660v3 |
2019-03-12 | Zero Field Assembly of Long Magnetic Dipolar Chains in 2D Polymer Nanocomposite Films | The existence of magnetic dipolar nanoparticle chains at zero field has been
predicted theoretically for decades, but these structures are rarely observed
experimentally. A prerequisite is a permanent magnetic moment on the particles
forming the chain. Here we report on the observation of magnetic dipolar chains
of sph... | 1903.04877v1 |
2019-04-09 | Back to the Lithium Plateau with J0023+0307 with [Fe/H]<-6 | We present an analysis of the UVES high-resolution spectroscopic observations
at the 8.2m VLT of J0023+0307, a main-sequence extremely iron-poor dwarf star.
We are unable to detect iron lines in the spectrum but derive [Fe/H]<-6.1 from
the Ca II resonance lines assuming [Ca/Fe]>0.40. The chemical abundance pattern
of J... | 1904.04892v1 |
2019-05-28 | Strain-derivative of thermoelectric properties: a sensitive probe for nematicity | The nematic instability of iron-based superconductors is an undebatable
ingredient of the physics of iron-based superconductors. Yet, its origin
remains enigmatic as it involves a fermiology with an intricate interplay of
lattice-, orbital- and spin- degrees of freedom. It is well known that
thermoelectric transport is... | 1905.11660v2 |
2019-06-07 | Identification of nutrient deficiency in bean plants by prompt chlorophyll fluorescence measurements and Artificial Neural Networks | The deficiency of macro (N, P, S, Ca, Mg and K) and micro (Zn, Cu, B, Mo, Cl,
Mn and Fe) minerals has a major effect on plant development. The lack of some
nutrient minerals especially of nitrogen, potassium, calcium, phosphorus and
iron is a huge problem for agriculture and early warning and prevention of the
problem ... | 1906.03312v1 |
2019-07-29 | Imaging Nematic Transitions in Iron-Pnictide Superconductors with a Quantum Gas | The SQCRAMscope is a recently realized Scanning Quantum CRyogenic Atom
Microscope that utilizes an atomic Bose-Einstein condensate to measure magnetic
fields emanating from solid-state samples. The quantum sensor does so with
unprecedented DC sensitivity at micron resolution from room-to-cryogenic
temperatures. An addi... | 1907.12601v2 |
2019-08-17 | Homogeneous Analysis of Hot Earths: Masses, Sizes, and Compositions | Terrestrial planets have been found orbiting Sun-like stars with extremely
short periods --- some as short as 4 hours. These "ultra-short-period planets"
or "hot Earths" are so strongly irradiated that any initial H/He atmosphere has
probably been lost to photoevaporation. As such, the sample of hot Earths may
give us ... | 1908.06299v2 |
2019-09-03 | Effects of spin-orbit coupling on spin-fluctuation induced pairing in iron-based superconductors | We perform a theoretical study of the leading pairing instabilities and the
associated superconducting gap functions within the spin-fluctuation mediated
pairing scenario in the presence of spin-orbit coupling (SOC). Focussing on
iron-based superconductors (FeSCs), our model Hamiltonian consists of a
realistic density ... | 1909.01313v1 |
2019-10-08 | Silicon and iron dust in gamma-ray burst host galaxy absorbers | Depletion studies provide a way to understand the chemical composition of
interstellar dust grains. We here examine 23 gamma-ray bursts (GRB) optical
afterglow spectra (spanning 0.6<z<5.0) and compare their silicon and iron
dust-phase column densities with different extinction curve parameters to study
the composition ... | 1910.03207v1 |
2019-10-18 | Trapping and electrical characterization of single core/shell iron-based nanoparticles in self-aligned nanogaps | We report on the fabrication and measurements of platinum-self-aligned
nanogap devices containing cubed iron (core)/iron oxide (shell) nanoparticles
(NPs) with two average different sizes (13 and 17 nm). The nanoparticles are
deposited by means of a cluster gun technique. Their trapping across the
nanogap is demonstrat... | 1910.08326v2 |
2020-02-17 | The Chandra High Resolution X-ray Spectrum of Quiescent Emission from Sgr A* | In quiescence, Sgr A* is surprisingly dim, shining 100,000 times less than
expected for its environment. This problem has motivated a host of theoretical
models to explain radiatively inefficient accretion flows (RIAFs). The Chandra
Galactic Center (GC) X-ray Visionary Program obtained approximately 3 Ms (one
month) of... | 2002.07198v1 |
2020-03-03 | Non-local correlations in Iron Pnictides and Chalcogenides | Deviations of low-energy electronic structure of iron-based superconductors
from density functional theory predictions have been parametrized in terms of
band- and orbital-dependent mass renormalizations and energy shifts. The former
have typically been described in terms of a local self-energy within the
framework of ... | 2003.01638v2 |
2020-03-27 | Distant sequence similarity between hepcidin and the novel coronavirus spike glycoprotein: a potential hint at the possibility of local iron dysregulation in COVID-19 | The spike glycoprotein of the SARS-CoV-2 virus, which causes COVID-19, has
attracted attention for its vaccine potential and binding capacity to host cell
surface receptors. Much of this research focus has centered on the ectodomain
of the spike protein. The ectodomain is anchored to a transmembrane region,
followed by... | 2003.12191v3 |
2020-03-27 | Boundary-obstructed topological high-T$_c$ superconductivity in iron pnictides | Non-trivial topology and unconventional pairing are two central guiding
principles in the contemporary search for and analysis of superconducting
materials and heterostructure compounds. Previously, a topological
superconductor has been predominantly conceived to result from a topologically
non-trivial band subject to ... | 2003.12204v2 |
2020-05-11 | Accurate Treatment of Comptonization in X-ray Illuminated Accretion Disks | A large fraction of accreting black hole and neutron stars systems present
clear evidence of the reprocessing of X-rays in the atmosphere of an
optically-thick accretion disk. The main hallmarks of X-ray reflection include
fluorescent K-shell emission lines from iron ($\sim 6.4-6.9$ keV), the
absorption iron K-edge ($\... | 2005.04852v1 |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.