The graphitic carbon nitride (g-C 3 N 4 ) is a promising layered two-dimension material with an opened bandgap. It is of interest to explore the tunability of the bandgap together with the magnetism by doping transition metal atoms. In this work, we investigated the transition metals (Mn, Fe, Co, Ni) and their hydroxides doped g-C 3 N 4 monolayers. The electron correlations between the 3 d electrons

A simple variational argument is presented which indicates that the spin–orbit coupling in itinerant systems can be enhanced by strong electronic correlations. The importance of the enhancement in the formation of the giant magnetic anisotropy found in the metallic paramagnetic and magnetically ordered states of compounds containing transition metal and light actinide elements (such as tetragonal Sr

We consider an elastic helical medium formed by uniformly rotating a triclinic crystal around a given axis to constitute a helical medium giving rise to a material whose tensor stiffness rotates uniformly and varies along the helix axis. A detailed analysis of its elastic properties has been done previously. Here, we are concerned in analyzing the role of thermal coupling with heat flow through the

Experimental studies indicate that 3D crystalline metal nanoclusters (NCs) intercalated under the surface of graphite have flat-topped equilibrated shapes. We characterize the shapes of these facetted NCs sandwiched between a blanketing graphene layer and the underlying graphite substrate. Specifically, we focus on the cases of fcc Cu and hcp Fe NCs. The analysis involves numerical minimization of

The Ising triangular lattice remains the classic test-case for frustrated magnetism. Here we report neutron scattering measurements of short range magnetic order in CuMnO 2 , which consists of a distorted lattice of Mn 3+ spins with single-ion anisotropy. Physical property measurements on CuMnO 2 are consistent with 1D correlations caused by anisotropic orbital occupation. However the diffuse magnetic

We investigated the possibility of superconductivity in monolayer hexagonal boron nitride (h-BN) doped using group-1 (Li, Na, K) and group-2 (Be, Mg, Ca, Sr, Ba) atoms via ab initio calculations. Consequently, we reveal that Sr- and Ba-doped monolayer h-BN and Ca-doped monolayer h-BN with 3.5% tensile strain are energetically stable and become superconductors with superconducting transition temperature

Transient current in transistor-like nanostructures has been studied by a model of a few electrons confined in a one-dimensional effective potential consisting of three quantum wells, ‘source’, ‘gate’, and ‘drain’. The time-dependent Schrödinger equation for the electrons has been integrated relying on the symplectic integrator method and the transient current has been calculated as the flux of the

La based Co–Fe combined double perovskite (La 1.8 Pr 0.2 CoFeO 6 ) was synthesized and the dielectric (zero-field and in-field), magnetic, x-ray absorption and Raman spectroscopy measurements have been investigated for La 1.8 Pr 0.2 CoFeO 6 double perovskite. The existence of re-entrant cluster glass state is observed. The magneto–dielectric (MD) is found in two temperature regions (25–80 K and 125–275

Lattice dynamic properties of the tetragonal modification of ZnP 2 and CdP 2 crystals (space group P4 1 2 1 2, no 92) are calculated within the density functional theory. Theoretical results are shown to compare favorably with available Raman scattering and infrared reflection/transmission experimental data, which allows assignment of Raman-and infrared-active modes to the specific lattice eigenmodes

Quasiparticle poisoning has remained one of the main challenges in the implementation of Majorana-based quantum computing. It inevitably occurs when the system hosting Majorana qubits is not completely isolated from its surrounding, thus considerably limiting its computational time. We propose the use of periodic driving to generate multiple Majorana fermions at each end of a single quantum wire, which

In this work, we studied the dynamics of the kinematic vortices (kV) in a mesoscopic superconductor under the influence of external applied magnetic fields ( H ) and transport currents ( J tr ). A J tr ( H ) phase diagram is determined. We show that the vortex dynamics are profoundly affected by the presence of constrictions and by H . We find that between the Meissner and normal states, the resistive

We study the spin-dependent transport and thermoelectric properties of ferromagnetic zigzag-edge phosphorene nanoribbon with N chains ( N -ZPNR) modulated by a perpendicular electric field (PEF). By adopting the Hubbard model Hamiltonian combined with the self-consistent calculation, and using the nonequilibrium Green’s function method, we obtain the band structure, spin-dependent transmission coefficients

We report inelastic neutron scattering (INS) investigations on the bilayer Fe-based superconductor CsCa 2 Fe 4 As 4 F 2 above and below its superconducting transition temperature T c ≈ 28.9 K to investigate the presence of a neutron spin resonance. This compound crystallises in a body-centred tetragonal lattice containing asymmetric double layers of Fe 2 As 2 separated by insulating CaF 2 layers and

We have grown thin films of CaAgAs by molecular beam epitaxy, which was theoretically proposed to be a topological insulator. The temperature dependence of resistivity and the carrier concentration at 4 K were similar to the reported results of bulk samples. However, the magnetoresistance exhibited a steep increase at low magnetic fields, a behavior not observed for bulk samples. This steep increase

Nonmagnetic graphene-based van der Waals heterotrilayers exhibit peculiar electronic features such as energetically and/or spatially resolved Dirac rings/cones. Here, using first-principles calculations we study the effect of magnetic proximity effect and mirror symmetry of antiferromagnetic CrAs 2 monolayer sandwiched between graphene on the Dirac cones. We clearly identify the common vertical shift

The analysis of the impact of spin–orbit coupling (SOC) on the Kondo state has generated considerable controversy, mainly regarding the dependence of the Kondo temperature T K on SOC strength. Here, we study the one-dimensional (1D) single impurity Anderson model (SIAM) subjected to Rashba ( α ) and Dresselhaus ( β ) SOC. It is shown that, due to time-reversal symmetry, the hybridization function between

Energy structure and electron coupling with local lattice vibrations have been investigated for deep centres in AlN using hybrid functional density functional theory. Local phonon energies and Huang–Rhys parameters have been calculated for defects and defect complexes containing most common unintentional impurities of carbon, oxygen and silicon, and for intrinsic vacancies, nitrogen split-interstitial

Quantum-confined electronic states such as quantum-well states (QWS) inside thin Pb(111) films and modified image-potential states (IPS) above the Pb(111) films grown on Si(111) 7 × 7 substrate were studied by means of low-temperature scanning tunnelling microscopy (STM) and spectroscopy (STS) in the regime of constant current I . By plotting the position of the n th emission resonances U n versus

Pb(Hf 1− x Sn x )O 3 single crystals with x = 0.23 were characterized using single-crystal x-ray diffraction in the wide temperature range. The information on the structure of two intermediate phases, situated between low temperature antiferroelectric and high temperature paraelectric phases, has been obtained. The lower-temperature intermediate AFE2 phase is characterized by incommensurate displacive

We review results of density functional theory calculations of the adsorption of single gold atoms and formation of sub-nanometer Au n structures ( n = 2 to 5) on most stable iron oxide surfaces: hematite (0001), and magnetite (111) and (001). Structural, energetic, and electronic properties of Au n structures on both Fe- and O-rich oxide terminations are discussed. Different chemical character of

The paper presents a semi-empirical wide-range equation of state (EOS) for platinum with account for melting, evaporation, and ionization. The equation is based on a wide spectrum of experimental and calculation data. Parameters for the EOS were adjusted using a genetic algorithm which proved to perform well for optimizations in big data processing. In the regions where no experimental data were available

We present an exact solution of the continuum Bogolyubov-de-Gennes Hamiltonian for Majorana bound states (MBSs) generated in a superconductor–semiconductor hybrid topological nanowire. The full energy spectra that include the band states and in-gap states could be obtained. We show that for relatively short wire length, the zero energy mode could be induced even in the topological trivial regime, which

We have theoretically analysed DC resistivity ( ρ ) in the Kondo-lattice materials using the powerful memory function formalism. The complete temperature evolution of ρ is investigated using the Wölfle–Götze expansion of the memory function. The resistivity in this model originates from spin–flip magnetic scattering of conduction s -electron off the quasi-localized d or f electron spins. We find the

Half-Heusler compounds usually exhibit relatively higher lattice thermal conductivity that is undesirable for thermoelectric applications. Here we demonstrate by first-principles calculations and Boltzmann transport theory that the BiBaK system is an exception, which has rather low thermal conductivity as evidenced by very small phonon group velocity and relaxation time. Detailed analysis indicates

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We report transport properties of Sb 2− x Sn x Te 3 ( x ⩽ 0.05) single crystals, where the tuning of the charge carrier densities via Sn doping significantly improves the magnetoresistance (MR) and the thermoelectric (TE) properties. The MR increases significantly at 2 K for x = 0.01, which reduces considerably with further Sn doping at x = 0.05. The MR results below 90 K for x = 0.01 satisfy the semi-classical

Metal adsorption upon the 3-fold and 5-fold symmetric surfaces of the i-Ag–In–Yb quasicrystal has led to the observation of unique growth modes. Here, we present a study of the growth of Pb upon the 2-fold i-Ag–In–Yb surface, where the growth mechanism is found to be different from those observed on the other, higher symmetry surfaces of the same system. Initial Pb atoms occupy non-chemically-specific

We study the infrared optical absorption of magnetopolaron resonance states in graphene in the strong magnetic field based on the Huybrechts’s model, in which polaron states are formed due to the strong coupling between electrons and surface optical (SO) phonons induced by the polar substrate. We propose the special magnetopolaron states ##IMG## [http://ej.iop.org/images/0953-8984/32/42/425005/cmaba293ieqn1

A study of a dd excitation in La 4 Ni 3 O 8 (La-438) using x-ray absorption scattering and resonant inelastic x-ray scattering (RIXS) at the Ni K-edge is presented. The incident energy dependence of this dd excitation shows a maximum at the 1 s → 4 p π transition. Its intensity at the main edge is proportional to the amount of incident x-ray polarization parallel to the c -axis. These observations

We successfully grew single crystals of Si- and Ge-square-net compounds of NbSiSb and NbGeSb whose excellent crystalline quality are verified using single-crystal x-ray diffraction θ –2 θ scans, rocking curves, scanning and transmission electron microscopies. Since these two compounds share major crystallographic similarity with the topological nodal-line semimetals of ZrSiS family, we employ density

We reexamine how quantum density fluctuations in condensates of ultra-cold Fermi gases lead to fluctuations in phonon times-of-flight, an effect that increases as density is reduced. We suggest that these effects should be measurable in pancake-like (two-dimensional) condensates on their release from their confining optical traps, providing their initial (width/thickness) aspect ratio is suitably large

It is predicted theoretically that various oxides (Al 2 O 3 , MgO, SiO 2 and TiO 2 ) under ultrafast excitation of the electronic system exhibit nonthermal phase transitions. In the bulk, Al 2 O 3 transiently forms a superionic phase via nonthermal phase transition, MgO and SiO 2 disorder, TiO 2 experiences solid–solid phase transition while thermal effects lead to melting. In the finite-size samples

Electroresistance (ER) has been intensively studied in low- and intermediate-bandwidth manganites, which possess phase separation characteristics. As for the Sr- and Ba-doped large-bandwidth manganites, however, few results about ER have been reported so far. Here we report ER effect in oxygen-deficient La 0.8 Ba 0.2 MnO 3− δ thin films, which were obtained by applying a large electric current (33

In this work we describe a proposal for a graphene-based nanostructure that modulates electric current even in the absence of a gap in the band structure. The device consists of a graphene p–n junction that acts as a Veselago lens that focuses ballistic electrons on the output lead. Applying external (electric and magnetic) fields changes the position of the output focus, reducing the transmission

Novel materials, which often exhibit surprising or even revolutionary physical properties, are necessary for critical advances in technologies. Simultaneous control of structural and physical properties via a small electrical current is of great significance both fundamentally and technologically. Recent studies demonstrate that a combination of strong spin–orbit interactions and a distorted crystal

In these last years large research efforts have been devoted to the synthesis and investigation of reducible metal oxide surfaces modified with metal atoms and nanoparticles for improving their performance in a number of advanced applications. Among reducible metal oxides, iron oxides have the advantage to be made up from two of the most common elements on Earth. In this paper we analyze the structural

We present a thorough density functional theory based computational study of crystalline properties of cubane caged potential energetic material octanitrocubane (ONC). As expected for a layered molecular solid, van der Waals corrections are inevitable and the same has been incorporated to capture the ground state properties more accurately. Study of Born effective charge and zone centered phonon frequencies

The calculation of the heat of formation of Sm(Co 1− x − y Fe x Ni y ) 5 compound using homemade software in the framework of Miedema’s model was carried out. In addition we investigated the influence of the probability of occupation the transition metals sites by 3d-ions, in particular, equiprobable distribution of 3d-ions among 2c and 3g sites and selective distribution Co/Ni-(2c), Fe-(3g). The maximal

In strongly correlated electron system, the impact of elementary substitution or intercalation plays a crucial role in determining electronic ground state among various macroscopic quantum phases such as charge order and superconductivity. Here, we report that simultaneous Cu intercalation and Ta substitution at Ti site in 1T-Cu x Ti 0.8 Ta 0.2 Se 2 induce an intrinsic electronic phase diagram, characterized

Facilitating interfacial thermal transport is highly desirable for various engineering applications, such as improving heat dissipation in microelectronics and efficiency of electrothermal heating element. Here, the interface thermal conductances (ITCs) of Cr 0.22 Ni 0.78 /MgO and Cr 0.22 Ni 0.78 /Al 2 O 3 interfaces are studied through the non-equilibrium molecular dynamics simulation. It is found

We report on the structure, spin–lattice and magneto-electric coupling in (1− x )Pb(Fe 2/3 W 1/3 )O 3 –( x )BiFeO 3 (where x = 0.1 and 0.4) (PBFW) solid solution synthesized through two-step solid-state reaction method. The room temperature (RT) crystallographic studies were carried out using x-ray diffraction and neutron diffraction measurements which show a single-phase Pseudocubic crystal system

There is an ongoing dispute in the community about the absence of a magnetic quantum critical point (QCP) in the noncentrosymmetric heavy fermion compound CeRhSi 3 . In order to explore this question we prepared single crystals of CeRh(Si 1− x Ge x ) 3 with x = 0.05 and 0.15 and determined the temperature–pressure ( T – p ) phase diagram by means of measurements of the electrical resistivity. The substitution

We study experimentally and numerically the dynamics of the spin ice material Dy 2 Ti 2 O 7 in the low temperature ( T ) and moderate magnetic field ( B ) regime ( T ∈ [0.1, 1.7] K, B ∈ [0, 0.3] T). Our objective is to understand the main physics shaping the out-of-equilibrium magnetisation vs temperature curves in two different regimes. Very far from equilibrium, turning on the magnetic field after

We theoretically investigate the Landau levels (LLs) and magneto-capacitance (MC) of monolayer black phosphorus under a perpendicular magnetic field, on which a parabolic potential is applied along with the armchair and zigzag directions, respectively. By both analytically perturbative calculation and numerical diagonalization based on an effective k ⋅ p Hamiltonian, we find that the LLs parabolically

Twinning is a known accommodation mechanism of graphene that results in low-energy microstructures or twins. In view of their mechanical stability, twins suggest themselves as a possible means of introducing extended defects in graphene leading to the opening of transmission band gaps. We investigate charge-carrier transmission across the twin structures in graphene using the Landauer–Büttiker (LB)

The nature of the amorphous state has been notably difficult to ascertain at the microscopic level. In addition to the fundamental importance of understanding the amorphous state, potential changes to amorphous structures as a result of radiation damage have direct implications for the pressing problem of nuclear waste encapsulation. Here, we develop new methods to identify and quantify the damage

We propose a thermodynamic model to the study the antiferroelectric (AFE) phase transitions in antiferroelectric–ferroelectric (AFE–FE) superlattices in which the coupling at the interface between two layers is mediated by local polarizations. Phase diagram of the AFE layer in term of the degree of interfacial effect λ and temperature T involving ferrielectric (FI) and ferroelectric (FE) phases is

The topological properties of non-Hermitian Hamiltonian is a hot topic, and the theoretical studies along this research line are usually based on the two-level non-Hermitian Hamiltonian (or, equivalently, a spin-1/2 non-Hermitian Hamiltonian). We are motivated to study the geometrical phases of a three-level Lieb lattice model (or, equivalently, a spin-1 non-Hermitian Hamiltonian) with the flat band

In this paper, we investigate non-single exponential photoluminescence decays in various disordered condensed-matter systems. For such materials, two formulas for the average lifetime of system’s excited state are commonly used in the analysis of experimental data. In many cases, the choice of formula is arbitrary and lacks a clear physical justification. For this reason, our main goal is to show that

Simulations on Bloch surface waves and Bloch surface wave–exciton–polaritons based on the transfer matrix method were performed using only the layer thicknesses and refractive indices of the materials. We demonstrate that the incorporation of the influence of active layer is necessary to accurately determine the Bloch surface wave dispersion. Furthermore, the mode splitting that gives rise to the lower

The chiral spin textures of a two-dimensional (2D) triangular system, where both antiferromagnetic (AF) Heisenberg exchange and chiral Dzyaloshinsky–Moriya interactions co-exist, are investigated numerically with an optimized quantum Monte Carlo method based on mean-field theory. We find that: helical, skyrmionic and vortical AF crystals can be formed when an external magnetic field is applied perpendicular

Resting on multi-scale modelling simulations, we explore dynamical aspects characterizing magnetic skyrmions driven by spin-transfer-torque towards repulsive and pinning 3 d and 4 d single atomic defects embedded in a Pd layer deposited on the Fe/Ir(111) surface. The latter is known to host sub-10 nm skyrmions which are of great interest in information technology. The Landau–Lifshitz–Gilbert equation

We report a metal–insulator like transition in single-crystalline 3D topological insulator Bi 2 Te 3 at a temperature of 230 K in the presence of an external magnetic field applied normal to the surface. This transition becomes more prominent at larger magnetic field strength with the residual resistance value increasing linearly with the magnetic field. At low temperature, the magnetic field dependence

The electronic structure and thermoelectric properties of ZrRuTe-based half-Heusler compounds are studied using density functional theory and Boltzmann transport formalism. Based on rigorous computations of electron relaxation time τ considering electron–phonon interactions and lattice thermal conductivity κ l considering phonon–phonon interactions, we find ZrRuTe to be an intrinsically good thermoelectric

Density functional theory calculations within the generalized gradient approximation are employed to study the ground state of Co 2 FeAl. Various magnetic configurations are considered to find out its most stable phase. The ferromagnetic ground state of the Co 2 FeAl is energetically observed with an optimized lattice constant of 5.70 Å. After that, the system was subjected under uniform and non-uniform

A step-like conductance as a function of the Fermi energy is theoretically predicted for a junction made of silicene, in which the energy gap in the junction can be controlled by a perpendicular electric field. When the electric field is applied at the central area of the junction, the transmission probability of an electron becomes partially suppressed and the calculated conductance behaves a step-like

Based on a model of coupled processes with differently time-dependent decay kinetics we present a critical review on photoluminescence (PL) and transient absorption (TA) experiments in undoped and Mg or Fe-doped LiNbO 3 , together with a comprehensive interpretation of visible radiative and parallel non-radiative decay processes on timescales ranging from 50 ns up to minutes. Analogies and peculiarities

We study the dynamics of a nonmagnetic impurity interacting with the surface states of a 3D and 2D topological insulator (TI). Employing the linked cluster technique we develop a formalism for obtaining the Green’s function of the mobile impurity interacting with the low-energy Dirac fermions. We show that for the non-recoil case in 2D, the Green’s function in the long-time limit has a power-law decay

An extensive analytical and numerical investigation has been carried out to examine the role played by many-body effects on various α - ##IMG## [http://ej.iop.org/images/0953-8984/32/41/415303/cmab9bcbieqn2.gif] {${\mathcal{T}}_{3}$} materials under an off-resonance optical dressing field. Additionally, we explore its dependence on the hopping parameter α as well as the electron–light coupling strength

The electron scattering from periodic line defects on the surface of topological insulators with hexagonal warping effect is investigated theoretically by means of a transfer matrix method. The influence of surface line defects, acting as structural ripples on propagation of electrons are studied in two perpendicular directions due to the asymmetry of warped energy contour under momentum exchange.