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2019-11-18
ONETEP + TOSCAM: uniting dynamical mean field theory and linear-scaling density functional theory
We introduce the unification of dynamical mean field theory (DMFT) and linear-scaling density functional theory (DFT), as recently implemented in ONETEP, a linear-scaling DFT package, and TOSCAM, a DMFT toolbox. This code can account for strongly correlated electronic behavior while simultaneously including the effects...
1911.07752v2
2019-11-21
First discovery of trans-iron elements in a DAO-type white dwarf (BD$-22{^\circ}3467$)
We have identified 484 lines of the trans-iron elements (TIEs) Zn, Ga, Ge, Se, Br, Kr, Sr, Zr, Mo, In, Te, I, Xe, and Ba, for the first time in the ultraviolet spectrum of a DAO-type WD, namely BD$-22{^\circ}3467$, surrounded by the ionized nebula Abell 35. Our TIE abundance determination shows extremely high overabund...
1911.09573v1
2019-11-25
Local metallicity distribution function derived from Galactic large-scale radial iron pattern modelling
We develop an approach for fitting the results of modeling of wriggling radial large scale iron pattern along the Galactic disk, derived over young (high massive) Cepheids, with the metallicity distribution, obtained using low mass long living dwarf stars in the close solar vicinity. For this, at the step of computing ...
1911.10842v1
2019-12-09
Pulsation in faint blue stars
Following the discovery of blue large-amplitude pulsators (BLAPs) by the OGLE survey, additional hot, high-amplitude pulsating stars have been discovered by the Zwicky Transient Facility. It has been proposed that all of these objects are low-mass pre-white dwarfs and that their pulsations are driven by the opacity of ...
1912.04129v1
2019-12-18
Giant enhancement of critical current density at high field in superconducting (Li,Fe)OHFeSe films by Mn doping
Critical current density (Jc) is one of the major limiting factors for high field applications of iron-based superconductors. Here, we report that Mn-ions are successfully incorporated into nontoxic superconducting (Li,Fe)OHFeSe films. Remarkably, the Jc is significantly enhanced from 0.03 to 0.32 MA/cm^2 under 33 T, a...
1912.08414v1
2019-12-19
The influence of hydrogen on plasticity in pure iron-theory and experiment
Tensile stress relaxation is combined with transmission electron microscopy to reveal dramatic changes in dislocation structure and sub structure in pure alpha iron as a result of the effects of dissolved hydrogen. We find that hydrogen charged specimens after plastic deformation display a very characteristic pattern o...
1912.09313v1
2019-12-22
Effects of momentum-dependent quasiparticle renormalization on the gap structure of iron-based superconductors
We discuss the influence of momentum-dependent correlations on the superconducting gap structure in iron-based superconductors. Within the weak coupling approach including self-energy effects at the one-loop spin-fluctuation level, we construct a dimensionless pairing strength functional which includes the effects of q...
1912.10453v3
2019-12-23
Measuring transferability issues in machine-learning force fields: The example of Gold-Iron interactions with linearized potentials
Machine-learning force fields have been increasingly employed in order to extend the possibility of current first-principles calculations. However, the transferability of the obtained potential can not always be guaranteed in situations that are outside the original database. To study such limitation, we examined the v...
1912.10761v3
2020-01-08
Nucleosynthesis in early rotating massive stars and chemical composition of CEMP stars
The first massive stars triggered the onset of chemical evolution by releasing the first metals (elements heavier than helium) in the Universe. The nature of these stars and how the early chemical enrichment took place is still largely unknown. Rotational-induced mixing in the stellar interior can impact the nucleosynt...
2001.02341v1
2020-01-17
Dissociated dislocation-mediated carbon transport and diffusion in austenitic iron
Dislocation-solute interaction plays fundamental roles in mechanical properties of alloys. Here, we disclose the essential features of dislocation-carbon interaction in austenitic Fe at the atomistic scale. We show that passage of a Shockley partial dislocation in face-centered cubic iron is able to move carbon atoms o...
2001.06196v1
2020-01-23
Testing general relativity with the stellar-mass black hole in LMC X-1 using the continuum-fitting method
The iron line and the continuum-fitting methods are currently the two leading techniques for measuring black hole spins with electromagnetic radiation. They can be naturally extended for probing the spacetime geometry around black holes and testing general relativity in the strong field regime. In the past couple of ye...
2001.08391v2
2020-01-24
Passivation mechanisms and pre-oxidation effects on model surfaces of FeCrNi austenitic stainless steel
Passivation mechanisms were investigated on (100)-oriented Fe-18Cr-13Ni surfaces with direct transfer between surface preparation and analysis by X-ray photoelectron spectroscopy and scanning tunneling microscopy and electrochemical characterization. Starting from oxide-free surfaces, pre-oxidation at saturation under ...
2001.09025v1
2020-02-04
Magnetically controlled vector based on E coli Nissle 1917
In this paper, it is first discovered that EcN has natural magnetically controlled properties, that is, E coli Nissle 1917 cells move in a gradient magnetic field of permanent magnets without artificial magnetic labeling. It is also shown in the paper that the cultivation of EcN in a medium enriched with iron chelates ...
2002.01958v1
2020-02-10
Structural and magneto-transport studies of iron intercalated Bi2Se3 single crystals
A detailed investigation on the structural and magneto-transport properties of iron intercalated Bi2Se3 single crystals have been presented. The x-ray diffraction and Raman studies confirm the intercalation of Fe in the van der Waals gaps between the layers. The electrical resistivity of the compounds decreases upon in...
2002.03609v2
2020-02-24
Local Structure of Mott Insulating Iron Oxychalcogenides La$_{2}$O$_{2}$Fe$_{2}$O$M$$_{2}$ ($M$ = S, Se)
We describe the local structural properties of the iron oxychalcogenides, La$_2$O$_2$Fe$_2$O$M_2$ ($M$ = S, Se), by using pair distribution function (PDF) analysis applied to total scattering data. Our results of neutron powder diffraction show that $M$ = S and Se possess similar nuclear structure at low and room tempe...
2002.10305v2
2020-03-06
Adsorption property of fatty acid on iron surface with $Σ$3(111) grain boundary
Reducing the coefficient of boundary friction on steel surfaces is one of key technologies to improve the efficiency of machines such as automotive engines. It has been shown that the boundary friction on nanostructured steel surfaces in the sliding test using hydrocarbon lubricant molecules is smaller than the frictio...
2003.03061v1
2020-03-12
Band Engineering of Dirac cones in Iron Chalcogenides
By band engineering the iron chalcogenide Fe(Se,Te) via ab-initio calculations, we search for topological surface states and realizations of Majorana bound states. Proposed topological states are expected to occur for non-stoichiometric compositions on a surface Dirac cone where issues like disorder scattering and char...
2003.05732v2
2020-03-24
Momentum dependent $d_{xz/yz}$ band splitting in LaFeAsO
We performed angle-resolved photoemission spectroscopy (ARPES) studies of the electronic structure of the nematic phase in LaFeAsO. Degeneracy breaking between the dxz and dyz hole bands near the {\Gamma} and M point is observed in the nematic phase. Different temperature dependent band splitting behaviors are observed...
2003.10618v1
2020-03-26
Quasiclassical theory of $C_4$-symmetric magnetic order in disordered multiband metals
Recent experimental studies performed in the normal state of iron-based superconductors have discovered the existence of the $C_4$-symmetric (tetragonal) itinerant magnetic state. This state can be described as a spin density wave with two distinct magnetic vectors ${\vec Q}_1$ and ${\vec Q}_2$. Given an itinerant natu...
2003.12124v1
2020-03-30
Electronic correlation effects and local magnetic moments in L1$_0$ phase of FeNi
We study the electronic and magnetic properties of L1$_0$ phase of FeNi, a perspective rare-earth-free permanent magnet, by using a combination of density functional and dynamical mean-field theory. Although L1$_0$ FeNi has a slightly tetragonally distorted fcc lattice, we find that magnetic properties of its constitue...
2003.13347v2
2020-03-03
Novel Meta-Heuristic Model for Discrimination between Iron Deficiency Anemia and B-Thalassemia with CBC Indices Based on Dynamic Harmony Search
In recent decades, attention has been directed at anemia classification for various medical purposes, such as thalassemia screening and predicting iron deficiency anemia (IDA). In this study, a new method has been successfully tested for discrimination between IDA and \b{eta}-thalassemia trait (\b{eta}-TT). The method ...
2004.00480v1
2020-04-03
Spin-Excitations Anisotropy in the Bilayer Iron-Based Superconductor CaKFe$_4$As$_4$
We use polarized inelastic neutron scattering to study the spin-excitations anisotropy in the bilayer iron-based superconductor CaKFe$_4$As$_4$ ($T_c$ = 35 K). In the superconducting state, both odd and even $L-$modulations of spin resonance have been observed in our previous unpolarized neutron scattering experiments ...
2004.01405v1
2020-04-13
Topological magnetic line defects in Fe(Te,Se) high-temperature superconductors
Magnetic impurity chains on top of conventional superconductors are promising platforms to realize Majorana modes. Iron-based high-temperature superconductors are known in the vicinity of magnetic states due to the strong Hund's coupling in iron atoms. Here we propose that the line defects with missing Te/Se anions in ...
2004.05848v1
2020-04-27
Permanent Magnet Penning Trap
The Penning trap has been investigated as the basis of a small nuclear fusion reactor using a superconducting solenoid magnet. To extend this investigation, we designed, constructed, and evaluated a permanent magnet Penning trap. The device consists of a solenoid formed from an annular array of neodymium bar magnets be...
2004.13103v1
2020-05-13
Importance of Fermi surface and magnetic interactions for the superconducting dome in electron doped FeSe intercalates
The van-der-Waals gap of iron chalcogenide superconductors can be intercalated with a variety of inorganic and organic compounds that modify the electron doping level of the iron layers. In Lix(C3N2H10)0.37FeSe, a dome in the superconducting transition temperature Tc has been reported to occur in the doping range of x=...
2005.06215v1
2020-06-07
Kinetics of segregation formation in elastic field of edge dislocation in bcc iron
We study the kinetics of the redistribution of impurity atoms in the elastic fields of dislocations by computer simulation methods. A work consists of several stages. The first is the simulation of a dislocation core structure with a Burgers vector along [100] direction by using the modified molecular static method. Th...
2006.04036v1
2020-06-10
Quantum-Critical Spin-Density Waves in Iron-Selenide High-Tc Superconductors
Hidden spin-density waves (hSDW) with Neel ordering vector (pi,pi) have been proposed recently as parent groundstates to electron-doped iron-selenide superconductors. Doping such groundstates can result in visible electron-type Fermi surface pockets and faint hole-type Fermi surface pockets at the corner of the folded ...
2006.05680v1
2020-06-11
Low thermal conductivity of iron-silicon alloys at Earth core conditions with implications for the geodynamo
Earth core is composed of iron (Fe) alloyed with light elements, e.g., silicon (Si). Its thermal conductivity critically affects Earth thermal structure, evolution, and dynamics, as it controls the magnitude of thermal and compositional sources required to sustain a geodynamo over Earth history. Here we directly measur...
2006.06271v2
2020-06-11
Double single-channel Kondo coupling in graphene with Fe molecules
We study the interaction between graphene and a single-molecule-magnet, [Fe4(L)2(dpm)6]. Focusing on the closest Iron ion in a hollow position with respect to the graphene sheet, we derive a channel selective tunneling Hamiltonian, that couples different d orbitals of the Iron atom to precise independent combinations o...
2006.06723v1
2020-06-24
Iron line reverberation mapping in Ghasemi-Nodehi-Bambi background
The reverberation associated with the iron line is the time lag between direct photons from the corona and the photons reflected from the disk. The resulting line spectrum is called the 2D transfer function. The shape of the 2D transfer function is determined by the geometry of spacetime and the properties of BH. In a ...
2006.13640v1
2020-07-13
Effect of interactions and non-uniform magnetic states on the magnetization reversal of iron nanowire arrays
Ordered ferromagnetic nanowire arrays are widely studied due to the diversity of possible applications. However, there is still no complete understanding of the relation between the array's parameters and its magnetic behavior. The effect of vortex states on the magnetization reversal of large-diameter nanowires is of ...
2007.06499v1
2020-07-19
Isostructural spin-density-wave and superconducting gap anisotropies in iron-arsenide superconductors
When passing through a phase transition, electronic system saves energy by opening energy gaps at the Fermi level. Delineating the energy gap anisotropy provides insights into the origin of the interactions that drive the phase transition. Here, we report the angle-resolved photoemission spectroscopy (ARPES) study on t...
2007.09572v1
2020-07-15
Structure and Properties of Thermoresponsive Diblock Copolymers Embedded with Metal Oxide Nanoparticles
Nanostructured polymer-metal oxide composites are a current research area of great importance due to its highlight applications in sensors, optics, catalysts and drug delivery. Particularly the use of thermoresponsive polymers gives more flexibilities and possibilities in the design and construction of polymer template...
2007.10111v1
2020-08-09
The Iron Line Profile from Warped Black Hole Accretion Disks
The profile of the fluorescent iron line from black hole accretion disks is a powerful diagnostic of black hole properties, such as spin and inclination. The state-of-the-art, however, considers an accretion disk whose angular momentum is aligned with that of the black hole; this is a very constraining assumption which...
2008.03829v2
2020-08-13
Detection of a possible multiphase ultra-fast outflow in IRAS 13349+2438 with NuSTAR and XMM-Newton
We present joint NuSTAR and XMM-Newton observations of the bright, variable quasar IRAS 13349+2438. This combined dataset shows two clear iron absorption lines at 8 and 9 keV, which are most likely associated with two layers of mildly relativistic blueshifted absorption, with velocities of 0.14c and 0.27c. We also find...
2008.05965v1
2020-08-18
Thickness-dependent electron momentum relaxation times in iron films
Terahertz time-domain conductivity measurements in 2 to 100 nm thick iron films resolve the femtosecond time delay between applied electric fields and resulting currents. This current response time decreases from 29 fs for thickest films to 7 fs for the thinnest films. The macroscopic response time is not strictly prop...
2008.07852v1
2020-09-14
BaCuS2: a superconductor with moderate electron-electron correlation
We show that the layered-structure BaCuS$_2$ is a moderately correlated electron system in which the electronic structure of the CuS layer bears a resemblance to those in both cuprates and iron-based superconductors. Theoretical calculations reveal that the in-plane $d$-$p$ $\sigma^*$-bonding bands are isolated near th...
2009.06230v1
2020-09-29
On the possibility of through passage of asteroid bodies across the Earth's atmosphere
We have studied the conditions of through passage of asteroids with diameters 200, 100 and 50 m, consisting of three types of materials -- iron, stone and water ice across the Earth's atmosphere with the minimum trajectory altitude 10--15 km. The conditions of this passage with subsequent exit into outer space with the...
2009.14234v1
2020-10-02
Effect of the surface shape of a large space body on its fragmentation in a planetary atmosphere
Employing the finite element and computational fluid dynamics methods, we have determined the conditions for the fragmentation of space bodies or preservation of their integrity when they penetrate into the Earth's atmosphere. The origin of forces contributing to the fragmentation of space iron bodies during the passag...
2010.01095v1
2020-10-09
Pressure-induced magnetism in iron-based superconductors $A$Fe$_2$As$_2$ ($A=$ K, Cs, Rb)
The magnetic properties of iron-based superconductors $A$Fe$_2$As$_2$ ($A=$K, Cs, and Rb), which are characterized by the V-shaped dependence of the critical temperature ($T_{\rm c}$) on pressure ($P$) were studied by means of the muon spin rotation/relaxation technique. In all three systems studied the magnetism was f...
2010.04448v1
2020-11-24
Short-range nematic fluctuations in Sr1-xNaxFe2As2 superconductors
Interactions between nematic fluctuations, magnetic order and superconductivity are central to the physics of iron-based superconductors. Here we report on in-plane transverse acoustic phonons in hole-doped Sr$_{1-x}$Na$_x$Fe$_2$As$_2$ measured via inelastic X-ray scattering, and extract both the nematic susceptibility...
2011.12444v1
2020-12-07
Magnetic anisotropy from linear defect structures in correlated electron systems
Correlated electron systems, particularly iron-based superconductors, are extremely sensitive to strain, which inevitably occurs in the crystal growth process. Built-in strain of this type has been proposed as a possible explanation for experiments where nematic order has been observed at high temperatures correspondin...
2012.03824v2
2020-12-08
Mean field theory and Monte Carlo simulation of Phase transitions and Magnetic Properties of a tridimensional Fe7S8 Compound
The structural, electronic and magnetic properties of Fe7S8 material have been studied within the framework of the ab-initio calculations, the mean field approximation (MFA) and Monte Carlo simulation (MCS). Our study shows that two forms of the iron atoms, Fe2+ with spin S=2, and Fe3+ with spin {\sigma}=5/2 are the mo...
2012.04306v1
2020-12-13
Under an Iron Sky: On the Entropy at the Start of the Universe
Curiously, our Universe was born in a low entropy state, with abundant free energy to power stars and life. The form that this free energy takes is usually thought to be gravitational: the Universe is almost perfectly smooth, and so can produce sources of energy as matter collapses under gravity. It has recently been a...
2012.06975v2
2020-12-24
Intrinsic Time-reversal-invariant Topological Superconductivity in Thin Films of Iron-based Superconductors
We establish quasi-two-dimensional thin films of iron-based superconductors (FeSCs) as a new high-temperature platform for hosting intrinsic time-reversal-invariant helical topological superconductivity (TSC). Based on the combination of Dirac surface state and bulk extended $s$-wave pairing, our theory should be direc...
2012.13411v2
2021-01-14
Thermal response of the iron-based Ba122 superconductor to in situ and ex situ processes
The thermal properties are one of the key parameters to control phase purity and microstructure of polycrystalline materials. The melting point of the iron-based BaFe2As2 superconductor (Ba122), which foresees high-field applications, remains controversial. In this work, thermogravimetry-differential scanning calorimet...
2101.05502v1
2021-01-19
Role of interface morphology on the martensitic transformation in pure Fe
Using classical molecular dynamics simulations, we study austenite to ferrite phase transformation in iron, focusing on the role of interface morphology. We compare two different morphologies; a \textit{flat} interface in which the two phases are joined according to Nishiyama-Wasserman orientation relationship vs. a \t...
2101.07468v1
2021-02-19
Superconducting FeSe monolayer with milli-electron volt Fermi energy
Iron selenide (FeSe) is an iron-based superconductor which shows unique properties, including strongly anisotropic superconducting gap, paramagnetism in undoped compound and extremely small Fermi pocket size. In this work, we demonstrate that the sizes of electron and hole pockets in FeSe monolayer become much smaller ...
2102.09792v1
2021-02-19
Revealing the intrinsic superconducting gap anisotropy in surface-neutralized BaFe$_2$(As$_{0.7}$P$_{0.3}$)$_2$
Alkaline-earth iron arsenide (122) is one of the most studied families of iron-based superconductors, especially for angle-resolved photoemission spectroscopy. While extensive photoemission results have been obtained, the surface complexity of 122 caused by its charge-non-neutral surface is rarely considered. Here, we ...
2102.09919v1
2021-02-22
Influence of the Fermi surface geometry on a Josephson effect between an iron-pnictide and conventional superconductors
We study Josephson junctions between a multi-band iron-pnictide Ba1-xNaxFe2As2 and conventional s-wave superconductors Nb and Cu/Nb bilayer. We observe that junctions with a Cu interlayer exhibit much larger IcRn, despite a weaker proximity-induced superconductivity. This counterintuitive result is attributed to the di...
2102.10972v1
2021-02-24
Intermediate mass and heavy Galactic cosmic-ray nuclei: the case of new AMS-02 measurements
The recent measurement of the spectra of intermediate mass nuclei and iron nuclei carried out with the AMS-02 experiment provided us with the most complete set of data on cosmic ray fluxes to date, and allowed us to test the standard model for the transport of these particles through the Galaxy to the finest details. W...
2102.12576v2
2021-03-06
Autonomous detection of molecular configurations in microscopic images based on deep convolutional neural network
In an effort to explore high-throughput processing of microscopic image data, a method based on deep convolutional neural network is proposed. The state-of-the-art computer vision algorithm, Faster R-CNN, was trained for the detection of iron (II) phthalocyanines on Se-terminated Au(111) platform resolved by scanning p...
2103.04213v1
2021-03-11
Stimuli-responsive assembly of iron oxide nanoparticles into magnetic flexible filaments
The combination of multiple functionalities in a single material is an appealing strategy for the de-velopment of smart materials with unique features. In this work, we present the preparation of thermoresponsive magnetic nanoparticles and their one-dimensional assembly into transient micro-filaments. The material is b...
2103.06837v1
2021-03-24
Proximity Effect of Epitaxial Iron Phthalocyanine Molecules on High-Quality Graphene Devices
Depositing magnetic insulators on graphene has been a promising route to introduce magnetism via exchange proximity interaction in graphene for future spintronics applications. Molecule-based magnets may offer unique opportunities because of their synthesis versatility. Here, we investigated the magnetic proximity effe...
2103.12974v1
2021-03-29
Fluorescence intensity correlation imaging with high resolution and elemental contrast using intense x-ray pulses
We theoretically investigate the fluorescence intensity correlation (FIC) of Ar clusters and Mo-doped iron oxide nanoparticles subjected to intense, femtosecond and sub-femtosecond XFEL pulses for high-resolution and elemental contrast imaging. We present the FIC of {\Ka} and {\Kah} emission in Ar clusters and discuss ...
2103.15872v1
2021-03-31
Slip band interactions and GND latent hardening in a galling resistant stainless steel
Slip activation, slip band interactions, and GND densities in iron-base, galling resistant alloy Nitronic 60 have been characterised at the grain length scale using small-scale mechanical testing with high resolution digital image correlation and high-angular resolution electron backscatter diffraction. By correlating ...
2103.16864v1
2021-01-21
Time-Dependent Density Functional Theory Applied to Average Atom Opacity
We focus on studying the opacity of iron, chromium, and nickel plasmas at conditions relevant to experiments carried out at Sandia National Laboratories [J. E. Bailey et al., Nature 517, 56 (2015)]. We calculate the photo-absorption cross-sections and subsequent opacity for plasmas using linear response time-dependent ...
2104.00551v1
2021-04-15
Unconventional iron-magnesium compounds at terapascal pressures
Being a lithophile element at ambient pressure, magnesium is long believed to be immiscible with iron. A recent study by Gao et al. [1] showed that pressure turns magnesium into a siderophile element and can produce unconventional Fe-Mg compounds. Here, we extend the investigation to exoplanetary pressure conditions us...
2104.07700v1
2021-04-19
Infrared phonon spectroscopy on the Cairo pentagonal antiferromagnet Bi2Fe4O9: a study through the pressure induced structural transition
Magnetic and crystallographic transitions in the Cairo pentagonal magnet Bi2Fe4O9 are investigated by means of infrared synchrotron-based spectroscopy as a function of temperature (20 - 300 K) and pressure (0 - 15.5 GPa). One of the phonon modes is shown to exhibit an anomalous softening as a function of temperature in...
2104.09384v1
2021-04-21
The effect of core formation on surface composition and planetary habitability
The melt productivity of a differentiated planet's mantle is primarily controlled by its iron content, which is itself approximated by the planet's core mass fraction (CMF). Here we show that estimates of an exo-planet's CMF allows robust predictions of the thickness, composition and mineralogy of the derivative crust....
2104.10612v1
2021-04-22
Hund's metal crossover and superconductivity in the 111 family of iron-based superconductors
We study LiFeP, LiFeAs and NaFeAs in their paramagnetic metallic phase including dynamical electronic correlations within a density functional theory + slave-spin mean-field framework. The three compounds are found to lie next to the crossover between a normal and a Hund's metal, where a region of enhanced electronic c...
2104.11018v1
2021-05-03
A Bayesian Method for Estimating Uncertainty in Excavated Material
This paper proposes a method to probabilistically quantify the moments (mean and variance) of excavated material during excavation by aggregating the prior moments of the grade blocks around the given bucket dig location. By modelling the moments as random probability density functions (pdf) at sampled locations, a for...
2105.00600v1
2021-05-19
Thermal conductivity of iron and nickel during melting: Implication to Planetary liquid outer core
We report the measurements of the thermal conductivity ($\kappa$) of iron (Fe) and nickel (Ni) at high pressures and high temperatures. $\kappa$ values are estimated from the temperature measurements across the sample surface in a laser heated diamond anvil cell (LHDAC) and using the COMSOL software. Near-isothermal $\...
2105.08962v1
2021-05-19
Origin of insulating ferromagnetism in iron oxychalcogenide Ce$_2$O$_2$FeSe$_2$
An insulating ferromagnetic (FM) phase exists in the quasi-one-dimensional iron chalcogenide Ce$_2$O$_2$FeSe$_2$ but its origin is unknown. To understand the FM mechanism, here a systematic investigation of this material is provided, analyzing the competition between ferromagnetic and antiferromagnetic tendencies and t...
2105.09239v2
2021-05-24
Unveiling non-Abelian statistics of vortex Majorana bound states in iron-based superconductors using fermionic modes
Motivated by the recent experiments that reported the discovery of vortex Majorana bound states (vMBSs) in iron-based superconductors, we establish a portable scheme to unveil the non-Abelian statistics of vMBSs using normal fermionic modes. The unique non-Abelian statistics of vMBSs is characterized by the charge flip...
2105.11199v1
2021-05-24
Redox hysteresis of super-Earth exoplanets from magma ocean circulation
Internal redox reactions may irreversibly alter the mantle composition and volatile inventory of terrestrial and super-Earth exoplanets and affect the prospects for atmospheric observations. The global efficacy of these mechanisms, however, hinges on the transfer of reduced iron from the molten silicate mantle to the m...
2105.11208v1
2021-05-27
Iron phthalocyanine on Au(111) is a "non-Landau" Fermi liquid
The paradigm of Landau's Fermi liquid theory has been challenged with the finding of a strongly interacting Fermi liquid that cannot be adiabatically connected to a non-interacting system. A spin-1 two-channel Kondo impurity with anisotropy D has a quantum phase transition between two topologically different Fermi liqu...
2105.13248v2
2021-06-04
Finite element stress analysis of a combined stacker-reclaimer machine: A design audit report
Design audit or design verification is an important step in engineering of heavy mobile materials handling equipment. Usually, the costumers employ third parties for audition of contractors engineering. Here a part of design audit of a combined stacker-reclaimer machine is reported. This equipment is designed and const...
2106.02291v1
2021-06-16
Random iron-nickel alloys: From first principles to dynamic spin fluctuation theory
We provide a systematic analysis of finite-temperature magnetic properties of random alloys Fe$_x$Ni$_{1-x}$ with the face-centered-cubic structure over a broad concentration range $x$. By means of the spin-polarized relativistic Korringa-Kohn-Rostoker method we calculate the electronic structure of disordered iron-nic...
2106.08765v2
2021-06-22
Quantum-confined charge transfer that enhances magnetic anisotropy in lanthanum M-type hexaferrites
Iron-based hexaferrites are critical-element-free permanent magnet components of magnetic devices. Of particular interest is electron-doped M-type hexaferrite i.e., LaFe$_{12}$O$_{19}$ (LaM) in which extra electrons introduced by lanthanum substitution of barium/strontium play a key role in uplifting the magnetocrystal...
2106.11947v1
2021-07-02
Breakdown of the Hund's Rule in CuFeAs
The ground-state properties of CuFeAs were investigated by applying density functional theory calculations within generalized gradient approximation (GGA) and GGA+U. We find that the bicollinear antiferromagnetic state with antiparallel orbital magnetic moments on each iron which violates the Hund's rule is favored by ...
2107.01014v1
2021-07-06
The role of orbital nesting in the superconductivity of Iron-based Superconductors
We analyze the magnetic excitations and the spin-mediated superconductivity in iron-based superconductors within a low-energy model that operates in the band basis but fully incorporates the orbital character of the spin excitations. We show how the orbital selectivity, encoded in our low-energy description, simplifies...
2107.02825v2
2021-07-14
Phase-manipulation-induced Majorana Mode and Braiding Realization in Iron-based Superconductor Fe(Te,Se)
Recent experiment reported the evidence of dispersing one-dimensional Majorana mode trapped by the crystalline domain walls in FeSe$_{0.45}$Te$_{0.55}$. Here, we perform the first-principles calculations to show that iron atoms in the domain wall spontaneously form the ferromagnetic order in line with orientation of th...
2107.06558v3
2021-07-15
Multipolar nematic state of nonmagnetic FeSe based on the DFT+$U$
Clarifying the origin of nematic state in FeSe is one of urgent problems in the field of iron-based superconductivity. Motivated by the discovery of a nematic solution in the density-functional theory implemented by on-site Coulomb interaction (DFT+$U$) [npj Quantum Mater. \textbf{5}, 50 (2020)], we reexamine the $U$ d...
2107.07244v3
2021-07-16
Discovery and implications of hidden atomic-scale structure in a metallic meteorite
Iron and its alloys have made modern civilisation possible, with metallic meteorites providing one of the human's earliest sources of usable iron as well as providing a window into our solar system's billion-year history. Here highest-resolution tools reveal the existence of a previously hidden FeNi nanophase within th...
2107.07909v1
2021-07-24
Controllable Majorana vortex states in iron-based superconducting nanowires
There has been experimental evidence for the Majorana zero modes (MZMs) in solid state systems, which are building blocks for potential topological quantum computing. It is important to design devices, in which MZMs are easy to manipulate and possess a broad topological non-trivial parameter space for fusion and braidi...
2107.11562v1
2021-08-07
Strong Momentum-Dependent Electron-Magnon Renormalization of a Surface Resonance on Iron
The coupling of fermionic quasiparticles to magnons is essential for a wide range of processes, from ultrafast magnetization dynamics in ferromagnets to Cooper pairing in superconductors. Although magnon energies are generally much larger than phonon energies, up to now their electronic band renormalization effect in f...
2108.03421v1
2021-08-13
Discovery of mesoscopic nematicity wave in iron-based superconductors
Nematicity is ubiquitous in electronic phases of high transition temperature superconductors, particularly in iron-based superconductors (IBSCs). Order parameter that characterizes the nematic phase has been investigated in momentum space, but its real-space arrangement remains largely unclear. We use linear dichroism ...
2108.06122v3
2021-08-17
Importance of the many-body effects for structural properties of the novel iron oxide: Fe$_2$O
The importance of many-body effects on electronic and magnetic properties and stability of different structural phases was studied in novel iron oxide - Fe$_2$O. It was found that while Hubbard repulsion hardly affects the electronic spectrum of this material ($m^*/m \sim 1.2$), but it strongly changes its phase diagra...
2108.07645v1
2021-08-26
Magnetic design study of coil-dominated superconducting quadrupole magnets based on racetrack coils
Several coil structures have been used in accelerator superconducting quadrupole magnets, and cos2{\theta} quadrupole magnets are the most mature in theoretical research and engineering applications. However, the cos2{\theta} quadrupole magnet has a complicated coil structure, especially at the end of the coil, which m...
2108.11643v1
2021-09-13
Pseudospin-Triplet Pairing in Iron-Chalcogenide Superconductors
We study superconductivity of electron systems with both spin and pseudospin-1/2 degrees of freedom. By solving linearized gap equations, we derive a weak coupling criterion for the even-parity spin-singlet pseudospin-triplet pairing. It can generally mix with the on-site s-wave pairing since both of them belong to the...
2109.06039v4
2021-09-15
Exploring DFT$+U$ parameter space with a Bayesian calibration assisted by Markov chain Monte Carlo sampling
Density-functional theory is widely used to predict the physical properties of materials. However, it usually fails for strongly correlated materials. A popular solution is to use the Hubbard corrections to treat strongly correlated electronic states. Unfortunately, the exact values of the Hubbard $U$ and $J$ parameter...
2109.07617v1
2021-09-16
Zero-energy Andreev bound states in iron-based superconductor Fe(Te,Se)
Majorana bound states have been predicted to exist in vortices of topological superconductors (SC). A realization of the Fu-Kane model, based on a three-dimensional topological insulator brought into proximity to an $s$-wave SC, in iron-based SC Fe(Te,Se) has attracted strong interest after pronounced zero-energy bias ...
2109.08200v1
2021-09-29
High-performance Ba1-xKxFe2As2 superconducting joints for persistent current operation
Superconducting joints are one of the key technologies to make Ba1-xKxFe2As2 (Ba-122) superconducting wires or tapes for high-field applications. Herein, superconducting joints were fabricated by a simple cold-pressing method, and the joint resistance of the iron-based superconducting joint was estimated for the first ...
2109.14300v1
2021-10-06
A New Weakly Supervised Learning Approach for Real-time Iron Ore Feed Load Estimation
Iron ore feed load control is one of the most critical settings in a mineral grinding process, directly impacting the quality of final products. The setting of the feed load is mainly determined by the characteristics of the ore pellets. However, the characterisation of ore is challenging to acquire in many production ...
2110.04063v1
2021-10-13
Oxygen adsorption induced superconductivity in ultrathin FeTe film on SrTiO3(001)
The phenomenon of oxygen incorporation induced superconductivity in iron telluride (Fe1+yTe, with antiferromagnetic (AFM) orders) is intriguing and quite different from the case of FeSe. Until now, the microscopic origin of the induced superconductivity and the role of oxygen are far from clear. Here, by combining in-s...
2110.06417v1
2021-10-20
High-entropy ejecta plumes in Cassiopeia A from neutrino-driven convection
Recent multi-dimensional simulations suggest that high-entropy buoyant plumes help massive stars to explode. Outwardly protruding iron-rich fingers in the galactic supernova remnant Cassiopeia A are uniquely suggestive of this picture. Detecting signatures of specific elements synthesized in the high-entropy nuclear bu...
2110.10384v1
2021-10-26
Tunable discontinuous shear thickening in capillary flow of MR suspensions
Very concentrated suspensions of iron particles in water or ethylene glycol can be obtained thanks to the use of superplasticizer molecules used in cement industry. At high volume fractions, these suspensions show a discontinuous shear thickening which was thoroughly characterized in rotational geometries. We will show...
2110.13759v1
2021-12-04
Quantitative relationship between structural orthorhombicity, shear modulus and heat capacity anomaly of the nematic transition in iron-based superconductors
Electronic nematicity in iron pnictide materials has been extensively studied by various experimental techniques, yet its heat capacity anomaly at the phase transition has not been examined quantitatively. In this work we review the thermodynamic description of nematicity in $Ba(Fe_{1-x}Co_{x})_{2}As_{2}$ using the Lan...
2112.02239v2
2021-12-23
The Three-Dimensional Collapse of a Rapidly Rotating 16 $M_{\odot}$ Star
We report on the three-dimensional (3D) hydrodynamic evolution to iron core-collapse of a rapidly rotating 16 $M_{\odot}$ star. For the first time, we follow the 3D evolution of the angular momentum (AM) distribution in the iron core and convective shell burning regions for the final 10 minutes up to and including grav...
2112.12800v1
2021-12-28
Cluster structure of superconducting phase and the nature of peaks in the doping dependences of the London penetration depth in iron pnictides
The mechanism of formation of dome-like phase diagrams and the features of magnetic field penetration in iron pnictides with hetero- and isovalent doping are considered within the framework of the previously proposed model, which assumes the local character of doping and the cluster structure of resulted superconductin...
2112.14167v2
2022-01-18
The Wrought Iron Beauty of Poncelet Loci
We've built a web-based tool for the real-time interaction with loci of Poncelet triangle families. Our initial goals were to facilitate exploratory detection of geometric properties of such families. During frequent walks in my neighborhood, it appeared to me Poncelet loci shared a palette of motifs with those found i...
2201.06960v1
2022-01-18
In-situ alignment of anisotropic hard magnets of 3D printed magnets
Within this work, we demonstrate in-situ easy-axis alignment of single-crystal magnetic particles inside a polymer matrix using fused filament fabrication. Two different magnetic materials are investigated: (i) Strontium hexaferrite inside a PA6 matrix, fill grade: 49 vol% and (ii) Samarium iron nitride inside a PA12 m...
2201.07111v1
2022-01-19
Nodal multigap superconductivity in the anisotropic iron-based compound RbCa2Fe4As4F2
The 12442 compounds are a recently discovered family of iron-based superconductors, that share several features with the cuprates due to their strongly anisotropic structure, but are so far poorly understood. Here, we report on the gap structure and anisotropy of RbCa2(Fe1-xNix)4As4F2 single crystals, investigated by a...
2201.07593v1
2022-01-24
Hund's coupling and electronic anisotropy in the spin-density wave state of iron pnictides
In the multiband systems, Hund's coupling ($J$) plays a significant role in the spin and charge excitations. We study the dependence of electronic anisotropy on $J$ in terms of Drude-weight along different directions as well as the orbital order in the four-fold symmetry broken spin-density wave state of iron pnictides...
2201.09808v1
2022-01-24
Low-energy physics for an iron phthalocyanine molecule on Au(111)
The system of an iron phthalocyanine molecule on the Au(111) surface, has been studied recently due to its peculiar properties. In particular, several surprising results of scanning tunneling spectroscopy changing the position of the molecule and applying magnetic field can be explained by the {\it non-Landau} Fermi li...
2201.10010v2
2022-01-25
Multiscale machine-learning interatomic potentials for ferromagnetic and liquid iron
We develop and compare four interatomic potentials for iron: a simple machine-learned embedded atom method (EAM) potential, a potential with machine-learned two- and three-body-dependent terms, a potential with machine-learned EAM and three-body terms, and a Gaussian approximation potential with the SOAP descriptor. Al...
2201.10237v1
2022-01-31
Mathematical analysis of a thermodynamically consistent reduced model for iron corrosion
We are interested in a reduced model for corrosion of iron, in which ferric cations and electrons evolve in a fixed oxide layer subject to a self-consistent electrostatic potential. Reactions at the boundaries are modeled thanks to Butler-Volmer formulas, whereas the boundary conditions on the electrostatic potential m...
2201.13193v1
2022-05-10
A Machine-Learned Spin-Lattice Potential for Dynamic Simulations of Defective Magnetic Iron
A machine-learned spin-lattice interatomic potential (MSLP) for magnetic iron is developed and applied to mesoscopic scale defects. It is achieved by augmenting a spin-lattice Hamiltonian with a neural network term trained to descriptors representing a mix of local atomic configuration and magnetic environments. It rep...
2205.04732v1
2022-05-26
Elastoresistivity of heavily hole doped 122 iron pnictides superconductors
Nematicity in the heavily hole-doped iron pnictide superconductors remains controversial. Sizeable nematic fluctuations and even nematic orders far from a magnetic instability were declared in RbFe$_2$As$_2$ and its sister compounds. Here we report a systematic elastoresistance study of series of isovalent- and electro...
2205.13663v1