Using density functional calculations, we elucidate the interaction between magnons and phonons on Fe(001) and O/Fe(001) surfaces. The effective Heisenberg exchange parameters between neighbor sites (Ji) were derived by fitting the ab initio spin spiral dispersion relation to a classical Heisenberg model. In bulk Fe, J5b has a larger amplitude than J2b-J4b. Surface magnons were softer on the Fe(001)

We successfully fabricate high-entropy alloys and amorphous alloy composites by adopting the proposed ultrasonic vibration method. The low-stress, low-temperature method enables us to create composites that combine both amorphous and crystalline properties. Microscopic observations and computed tomography measurements indicate good bonding quality without pores or cracks in the composites. Due to the

In this work, HengYan Wang and Jian Pan contributed equally to this work. The annotation for the contribution was omitted in the original publication of this paper [1]. It can be conformed in the submitted PDF version of the manuscript. Hence, the sentence “HengYan Wang and Jian Pan contributed equally to this work.” should be added.

We theoretically investigate the optical second-order sideband generation (OSSG) in an optical parity-time (PT) symmetric system, which consists of a passive cavity trapping the atomic ensemble and an active cavity. Compared with the double-passive system, it is found that near the exceptional point (EP), the efficiency of the OSSG increases sharply not only for the blue probepump detuning resonant

Investigations into the phonon behavior provide important information on interactions between different excitations in quantum materials. We perform a detailed study of the phonon behavior in the topological insulator Sn-doped Bi1.1Sb0.9Te2S using infrared spectroscopy. We observe two IR-active phonon modes at about 64 and 165 cm−1, which are labeled with α and β, respectively. While the evolution

We report a comparative investigation of the topographic features and nanomechanical responses of surface nanobubbles, polymeric nanodrops, and solid microparticles submerged in water and probed by atomic force microscopy in different operating modes. We show that these microscopic objects exhibit similar topographies, either hemispherical or hemiellipsoidal, in the standard tapping mode, and thus

In this work, (-2 0 1) β-Ga2O3 films are grown on GaN substrate by metal organic chemical vapor deposition (MOCVD). It is revealed that the β-Ga2O3 film grown on GaN possesses superior crystal quality, material homogeneity and surface morphology than the results of common heteroepitaxial β-Ga2O3 film based on sapphire substrate. Further, the relevance between the crystal quality of epitaxial β-Ga2O3

The Hubble constant H0 represents the expansion rate of the Universe at present and is closely related to the age of the Universe. The accurate measurement of Hubble constant is crucial for modern cosmology. However, different cosmological observations give diverse values of Hubble constant in literature. Up to now, there are two methods to measure the Hubble constant. One is to directly measure the

Recent studies on the electrical switching of tetragonal antiferromagnet (AFM) via Néel spin-orbit torque have paved the way for the economic use of antiferromagnetic materials. The most difficult obstacle that presently limits the application of antiferromagnetic materials in spintronics, especially in memory storage applications, could be the small and fragile magnetoresistance (MR) in the AFM-based

Nonradiative carrier recombinations at deep centers in semiconductors are of great importance for both fundamental physics and device engineering. In this article, we provide a revised analysis of Huang’s original nonradiative multi-phonon (NMP) theory with ab initio calculations. First, we confirmed at the first-principles level that Huang’s concise formula gives the same results as the matrix-based

Antiferromagnets (AFMs) with chiral noncollinear spin structure have attracted great attention in recent years. However, the existing research has mainly focused on hexagonal chiral AFMs, such as Mn3Sn, Mn3Ga, Mn3Ge with low crystalline symmetry. Here, we present our systematical study for the face-centered cubic noncollinear antiferromagnetic Mn3Pt. By varying the alloy composition (x), we have successfully

The manufacturing of additives with projection micro litho stereo exposure (PµLSE) has provided an opportunity for the fabrication of metastructures with complex microstructures at micro-nano resolutions. However, the performance evaluation of as-fabricated metastructures is challenging. The benefit of synchrotron radiation-based 3D imaging techniques and advanced image processing methods makes it

Self-locked energy-absorbing systems have been proposed in previous studies to overcome the limitations associated with the round-tube systems because they can prevent the lateral splash of tubes from impact loadings without any constraints. In case of self-locked systems, the ellipse-shaped self-locked tube is considered to be an optimal design when compared with the ordinary circle-shaped self-locked

Controlling coal dust produced in the process of underground coal mining is imperative because it can cause serious health problems, such as pneumoconiosis. In the present work, we have conducted a comprehensive investigation of the adhesion and peeling process of a coal molecule on graphene using molecular dynamics (MD) simulation. First, we simulate the adhesion of a coal molecule on a graphene substrate

With the application of strain engineering in microelectronics, complex stress states are introduced into advanced semiconductor devices. However, there is still a lack of effective metrology for the decoupling analysis of the complex stress states in semiconductor materials. This paper presents an investigation on the 2-axis stress component decoupling of {100} monocrystalline silicon (c-Si) by using

As an alternative electrode material, transition metal oxides are promising candidates due to multivalent nature and oxygen vacancies present in the structure with facilitate redox reactions. The aim of this study is to explore the intrinsic mechanism of oxygen evolution reaction (OER) using two-dimensional thin film La1−xSrxCoO3 electrode as a model. Herein, we report a planar two-dimensional model

The myelination of axons was the last major evolution in the vertebrate nervous system. Myelin promotes the speed of action potential by two orders, and modulates the conduction of neurons, important for learning new skills. However, the intrinsic mechanism for high-speed information propagation in myelin in the nervous systems is still unclear. We propose that myelinated nerve fibres serve as dielectric

Topological crystalline insulator (TCI) is one of the symmetry-protected topological states. Any TCI can be deformed into a simple product state of several decoupled two-dimensional (2D) topologically nontrivial layers in its lattice respecting its crystalline symmetries called the layer construction (LC) limit. In this work, based on first-principles calculations we have revealed that both tetragonal

In this work, we study the effects of disorder on topological metals that support a pair of helical edge modes deeply embedded inside the gapless bulk states. Strikingly, we predict that a quantum spin Hall (QSH) phase can be obtained from such topological metals without opening a global band gap. To be specific, disorder can lead to a pair of robust helical edge states which is protected by an emergent

Voltage control of magnetism promises great energy efficiency in writing magnetic memory. Here, using Cr/Mo/CoFeB/MgO multilayers stable under high annealing temperatures up to 590°C, we significantly enhance the interfacial crystallinity, thereby the interface-originated perpendicular magnetic anisotropy (PMA), voltage-controlled magnetic anisotropy (VCMA), and interface magnetoelectric (ME) effect

We explore the possibility of using a gigaparsec-scale local void to reconcile the Hubble tension. Such a gigaparsec-scale void can be produced by multi-stream inflation where different parts of the observable universe follow different inflationary trajectories. These trajectories become different parts of the observable universe after inflation, when these scales return to the horizon. If these trajectories

A magnetic impurity embedded in a Fermi sea is collectively screened by a cloud of conduction electrons to form a Kondo singlet below a characteristic energy scale TK, the Kondo temperature, through the mechanism of the Kondo effect. We have reinvestigated the Kondo singlet by means of the newly developed natural orbitals renormalization group (NORG) method. We find that, in the framework of natural

The inconsistent Hubble constant values derived from cosmic microwave background (CMB) observations and from local distance-ladder measurements may suggest new physics beyond the standard ACDM paradigm. It has been found in earlier studies that, at least phenomenologically, non-standard recombination histories can reduce the ≳ 4δ Hubble tension to ∼ 2δ. Following this path, we vary physical and phenomenological

We perform an extensive review of the numerous studies and methods used to determine the total mass of the Milky Way. We group the various studies into seven broad classes according to their modeling approaches. The classes include: i) estimating Galactic escape velocity using high velocity objects; ii) measuring the rotation curve through terminal and circular velocities; iii) modeling halo stars

We theoretically studied the thermoelectric transport properties of a strongly correlated quantum dot system in the presence of the Kondo effect based on accurate numerical evaluations using the hierarchical equations of motion approach. The thermocurrent versus gate voltage shows a distinct sawtooth line-shape at high temperatures. In particular, the current changes from positive (hole charge) to

Ferromagnetic-structural transformation has been studied widely in MnCoGe-based materials. However, the magnetostructural transition (MST) from antiferromagnetic (AFM) orthorhombic phase to ferromagnetic (FM) hexagonal phase, which may lead to a large inverse magnetocaloric effect (MCE), has rarely been reported. Here, the introduction of Mn vacancy lowers the structural transition temperature while

The pulse profiles of the Crab pulsar (as well as some other pulsars) vary with time. They can lead to a major source of intrinsic timing noise, which lacks a detailed physical model. The phase separation Δ between the first left peak (P1) and the second right peak (P2) is a key parameter that shows the variations of pulse profiles for the Crab pulsar. It was found that the evolution of A has a tendency

Nucleosynthesis is a complex process in astro-nuclear evolution. In this work, we constructed a directed, multi-layer, nuclear reaction network, using the substrate-product method from a thermonuclear reaction database, JINA REACLIB. The network contained four layers, namely n-, p-, h- and r-, which correspond to the types of reactions involved in neutrons, protons, 4He and the remaining atomic particles

In this study, we investigated the micromagnetic dynamics of kπ-state skyrmions in a magnetic nanodot under a circular spin-polarized current and found an excited spin wave that can propagate persistently along the direction of the radius toward the center. This dynamic process is associated with two energetically favorable states in an oscillating period of spin waves. In this case, the spin-polarized

The relaxation kinetics and phase transformations of the confined D-mannitol (DM) in nanoporous alumina are studied in-situ using a high-precision nano-calorimeter. We find that the crystallization behavior can be suppressed when it is confined in nanopores smaller than 50 nm. The confined DM glass has a much smaller fragility (~76) than free DM glass (~125), confirming the enhanced glass-forming ability

β-Ga2O3 MOSFETs are demonstrated on heterogeneous Ga2O3-Al2O3-Si (GaOISi) substrate fabricated by ion-cutting process. Enhancement (E)- and depletion (D)-mode β-Ga2O3 transistors are realized on by varying the channel thickness (Tch). E-mode GaOISi transistor with a Tch of 15 nm achieves a high threshold voltage VTH of ∼8 V. With the same T increase, GaOISi transistors demonstrate more stable ON-current

We investigate what role the SKA neutral hydrogen (HI) intensity mapping (IM) and galaxy sky surveys will play in weighing neutrinos in cosmology. We use the simulated data of the baryon acoustic oscillation (BAO) measurements from the HI surveys based on SKA1 (IM) and SKA2 (galaxy) to do the analysis. For the current observations, we use the Planck 2015 cosmic microwave background (CMB) anisotropies

Non-Hermitian systems can exhibit exotic topological and localization properties. Here we elucidate the non-Hermitian effects on disordered topological systems using a nonreciprocal disordered Su-Schrieffer-Heeger model. We show that the non-Hermiticity can enhance the topological phase against disorders by increasing bulk gaps. Moreover, we uncover a topological phase which emerges under both moderate

To test the standard model (SM) precisely and to look for the clues deviating from SM, a proposal for determining the effective electro-weak mixing angles sin2 θfeff (particularly f = lept, c, b) is proposed. It is via observing the asymmetries (the forward-backward one AFB, the left-right one ALR and the combined left-right forward-backward one AFBLR) of the doubly heavy-flavored hadrons in the production

Compared with the moving concentrated load model, it is more realistic and proper to use the moving distributed mass and load model to simulate the dynamics of a train moving along a railway track. In the problem of a moving concentrated load, there is only one critical velocity, which divides the load moving velocity into two categories: subcritical and supercritical. The locus of a concentrated load

Particular types of plankton in aquatic ecosystems can coordinate their motion depending on the local flow environment to reach regions conducive to their growth or reproduction. Investigating their swimming strategies with regard to the local environment is important to obtain in-depth understanding of their behavior in the aquatic environment. In the present research, to examine an impact of the

We consider possible high temperature superconductivity (high-Tc) in transition metal compounds with a cubic zinc-blende lattice structure. When the electron filling configuration in the d-shell is close to d7, all three t2g orbitals are near half filling with strong nearest neighbor antiferromagnetic (AFM) superexchange interactions. We argue that upon doping, this electronic environment can be one

There is growing interest in revealing exotic properties of collective spin excitations in kagome-lattice ferromagnets such as magnon Hall effects, topological magnon insulators, and flat magnon bands. Using the well-established nearest-neighbor Heisenberg ferromagnet model with Dzyaloshinskii-Moriya interaction (DMI), in this study we uncover intriguing new aspects in the selectivity and topology

Heat-bath algorithmic cooling (HBAC) has been proven to be a powerful and effective method for obtaining high polarization of the target system. Its cooling upper bound has been recently found using a specific algorithm, the partner pairing algorithm (PPA-HBAC). It has been shown that by including cross-relaxation, it is possible to surpass the cooling bounds. Herein, by combining cross-relaxation

Energetic materials are solids that release a large amount of energy in combustion. The evaluation depends on both combustion heat and ignition temperature. Conventional non-metallic materials have low ignition temperature but small combustion heat, whereas metals have large combustion heat but high ignition temperatures. We show that many metallic glasses, combining the merits of both metals and non-metals

The Stokes-Einstein (SE) relation has been considered as one of the hallmarks of dynamics in liquids. It describes that the diffusion constant D is proportional to (τ/T)−1, where τ is the structural relaxation time and T is the temperature. In many glass-forming liquids, the breakdown of SE relation often occurred when the dynamics of the liquids becomes glassy, and its origin is still debated among

An intelligent solution method is proposed to achieve real-time optimal control for continuous-time nonlinear systems using a novel identifier-actor-optimizer (IAO) policy learning architecture. In this IAO-based policy learning approach, a dynamical identifier is developed to approximate the unknown part of system dynamics using deep neural networks (DNNs). Then, an indirect-method-based optimizer

Excellent thermoelectric performance in molecular junctions requires a high power factor, a low thermal conductance, and a maximum figure of merit (ZT) near the Fermi level. In the present work, we used density functional theory in combination with a nonequilibrium Green’s function to investigate the thermoelectric performance of carbon chain-graphene junctions with both strong-coupling and weak-coupling

There have been overwhelming observations of piezo-/ferroelectric phenomena in many biological tissues and macromolecules, boosting the development of bio-based smart devices and the applications using electromechanical coupling phenomena in biological systems. The electromechanical coupling is believed to be responsible for various biophysical behaviors and remarkable biomaterial properties. Despite

Chaos has been well understood in dynamic system, however, how the chaotic behavior occur in jerky flow in material, is still not clear, and is lack of specific chaotic attractor. Here the jerky evolution of lateral force and the stair-like fluctuation of lateral displacement are observed for Ni62Nb38(at.%) metallic glass film during nanoscratch process. This jerky flow is investigated by using the

Abstract The Medium Energy X-ray telescope (ME) is one of the three main telescopes on board the Insight hard X-ray modulation telescope (Insight-HXMT) astronomy satellite. ME contains 1728 pixels of Si-PIN detectors sensitive in 5–30 keV with a total geometrical area of 952 cm2. The application specific integrated circuit (ASIC) chip, VA32TA6, is used to achieve low power consumption and low readout

Abstract As China’s first X-ray astronomical satellite, the Hard X-ray Modulation Telescope (HXMT), which was dubbed as Insight-HXMT after the launch on June 15, 2017, is a wide-band (1-250 keV) slat-collimator-based X-ray astronomy satellite with the capability of all-sky monitoring in 0.2-3 MeV. It was designed to perform pointing, scanning and gamma-ray burst (GRB) observations and, based on the

Abstract Form factors are quantities that involve both asymptotic on-shell states and gauge invariant operators. They provide a natural bridge between on-shell amplitudes and off-shell correlation functions of operators, thus allowing us to use modern on-shell amplitude techniques to probe into the off-shell side of quantum field theory. In particular, form factors have been successfully used in computing

Abstract In this paper, we investigate the phase sensitivities in two-path optical interferometry with asymmetric beam splitters. Here, we present the optimal conditions for the transmission ratio and the phase of the beam splitter to gain the highest sensitivities for a general class of non-classical states with parity symmetry. Additionally, we address the controversial question of whether the scheme

Abstract The holographic duality allows to construct and study models of strongly coupled quantum matter via dual gravitational theories. In general such models are characterized by the absence of quasiparticles, hydrodynamic behavior and Planckian dissipation times. One particular interesting class of quantum materials are ungapped topological semimetals which have many interesting properties from

Abstract The Low Energy X-ray telescope (LE) is one of the three main instruments of the Insight-Hard X-ray Modulation Telescope (Insight-HXMT). It is equipped with Swept Charge Device (SCD) sensor arrays with a total geometrical area of 384 cm and an energy band from 0.7 to 13 keV. In order to evaluate the particle induced X-ray background and the cosmic X-ray background simultaneously, LE adopts

Abstract On December 27, 2018, the basic system of the third-generation BeiDou navigation satellite system (BDS-3) completed the deployment of its constellation of 18 MEO networking satellites as well as the construction of the operation control system (OCS) and began to provide basic navigation services to users worldwide. Compared with BDS-2, BDS-3 aims to offer users better navigation signals and

Abstract We theoretically investigate the intra-band transitions in Mobius molecules. Due to the weak magnetic response, the relative permittivity is significantly modified by the presence of the medium while the relative permeability is not. We show that there is hyperbolic dispersion relation induced by the intra-band transitions because one of the eigen-values of permittivity possesses a different

Abstract The Insight-Hard X-ray Modulation Telescope (Insight-HXMT) is a broadband X-ray and γ-ray (1-3000 keV) astronomy satellite. One of its three main telescopes is the High Energy X-ray telescope (HE). The main detector plane of HE comprises 18 NaI(Tl)/CsI(Na) phoswich detectors, where NaI(Tl) is used as the primary detector to measure ~ 20–250 keV photons incident from the field of view (FOV)

Abstract In this paper, 106 active regions (ARs) in the visible solar hemisphere in solar cycle 24 whose maximum sunspot groups’ areas were larger than 400 µh were selected. The association of their flare index (Iflare), largest flare magnitude (Mflare), and fastest coronal mass ejection (CME) velocity (VCME) with the vector magnetic field parameters were examined, and attempts were made to predict

Abstract Surface states that have a dz2 symmetry around the center of the surface Brillouin zone (BZ) have been regarded common in closely-packed surfaces of rare-earth metals. In this work, we report the electronic structure of dhcp La (0001) thin films by ultrahigh energy resolution angle-resolved photoemission spectroscopy (ARPES) and first principle calculations. Our first principle analysis is

Abstract Diluted magnetic semiconductors (DMSs) have traditionally been employed to implement spin-based quantum computing and quantum information processing. However, their low Curie temperature is a major hurdle in their use in this field, which creates the necessity for wide bandgap DMSs operating at room temperature. In view of this, a single-electron transistor (SET) with a global back-gate was

Abstract The indentation technique is widely used in measuring the mechanical properties of soft matter at the microscale or nanoscale, but still faces challenges by these unique properties as well as the consequent strong surface adhesion, including the strong nonlinear effect, unclear judgment of the contact point, difficulties in estimating the contact area, and the risk of the indenter piercing

Abstract In this paper, the separation-induced transition in an LPT (low-pressure turbine) cascade is investigated at low Reynolds number with DNS (direct numerical simulation). The transition process is accurately predicted giving good agreements between the DNS and experimental results. To illustrate the secondary instability of separation-induced transition in a low-disturbance environment, the