In this work, we theoretically demonstrate that the second order response can survive in a two-dimensional (2D) tilted type-I Dirac metal due to the time reversal symmetry (TRS) breaking. We find that, in the terahertz regime, the second harmonic generation (SHG) is appreciably strong and is widely depending on the tilting parameter, temperature, excitation frequency and the applied electric field

In this paper a quad-band, polarization-insensitive metamaterial perfect absorber (MPA) based on bi-layer graphene in the terahertz regime is presented. Initially, four models of the desired structure by using a single-layer graphene metasurface were examined. The results of the proposed four models show that two absorption peaks were finally achieved at frequencies of 3.19 THz and 4.66 THz with the

Twin graphene is a novel two-dimensional semiconducting carbon allotrope with an intrinsic direct bandgap. To explore the excellent properties and potential applications of twin graphene, we performed first-principle density functional theory calculations on the structural, electronic, and magnetic properties of twin graphene with dual-doping of Al and Y (YB, N, O) atoms at different sites (ortho,

This paper reports on a few layer boron doped graphene with high homogeneity, stability and size. To achieve this, we employed diborane to synthesize a boron doped graphene film in a CVD system. During synthesis, we investigated the effect of diborane flow and growth time on copper foil to optimize doped graphene growth conditions. Raman spectroscopy, XPS, EDXS and ellipsometer were employed for the

The conduction properties of a graphene-graphene junction originated by a linear defect are analyzed. We provide a generalization of the Dirac Hamiltonian model taking into account the Fermi velocity gradient at the interface. General boundary conditions for the scattering problem are derived within the framework of the matching matrix method. We show that the scattering properties of the interface

Antimony phosphorus in the alpha phase (α-SbP) is a novel two-dimensional binary material with suitable band gap and environmental stability, it has attracted attention for its promising applications in the field of optoelectronics. In this work, the electronic and optical properties of α-SbP monolayer under biaxial strain have been studied by first principles calculation method based on density functional

The exact solution of ferromagnetic two-dimensional (2D) Ising model with a transverse field, which can be used to describe the critical phenomena in low-dimensional quantum spin systems, is derived by equivalence between the ferromagnetic 2D Ising model with a transverse field and the ferromagnetic three-dimensional (3D) Ising model. The results obtained in this work can be extended to be suitable

We have theoretically studied the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction in zigzag gapped graphene nanotube in the presence of Holstein phonons. We investigate the effect of quantities such as the gap parameter, intensity of the electron-phonon interaction, nanotube diameter, next nearest neighbor hopping parameter, chemical potential, etc. on the spatial behavior of the RKKY interaction

The effect of F and H dopants on the structural, elasticothermal and piezoelectric properties of Janus GeC hybrids is studied using ab-initio calcultaions. The large elastic regions observed reveal a high flexibility of Janus structures. A high rigidity with a hyperelastic softening behavior are observed for this class of materials making them very potential for automotive industry. Configurations

The anomalous magnetoresistance caused by the weak antilocalization (WAL) effects in 200-nm HgTe films is experimentally studied. This system is a high quality 3D topological insulator that has much stronger spatial separation of surface states compare to previously studied thinner HgTe structures. However, in contrast to that films, the system under study is characterized by a reduced strain resulting

In this paper, we investigate the absorption characteristic of the graphene-stack-based metamaterial absorber at the lower terahertz frequency range for the ultrathin and ultrabroadband. The absorption spectrum can be dynamically controlled by changing the gate voltage on the graphene-stack cavity. The thickness of a designed structure is only λ0/25.5 with respect to the center frequency. The absorption

The multicaloric properties of multiferroic A2Cu2Mo3O12 (A = Rb and Cs) compounds are theoretically investigated through a frustrated one-dimensional spin ribbon chain of CuO2. The system submitted to external magnetic and electric field constraints grants the particular interest of metamagnetoelectric effect arising at relatively low temperatures. The isentropes of Rb2Cu2Mo3O12 and Cs2Cu2Mo3O12 exhibit

We used first-principles density functional theory to study the physical properties of TaAs sheet. The effect of the strain on the energy band structure and transport properties was investigated. The results show that the Weyl point of TaAs can be destroyed by the strain, and new Weyl points are generated as the strain increases. The electron transmission and the strain resistance were used to describe

Combined effect of magnetic and the intense laser fields on the donor-bound magnetic polaron of semi-magnetic core shell nanostructures is investigated theoretically to explore them for opto-electronic, spintronic devices. Based on the band alignments of donor, the two probable semi-magnetic Core Shell Nanostructures (CSNs) namely type I CdTe/Cd0.7Mn0.3Te and reverse type I Cd0.7Mn0.3Te/CdTe are considered

In this work, we artificially create new metastable allotropes (called 1OT) of the two-dimensional (2D) Pd transition metal dichalcogenides (TMD) PdS2, PdSe2 and PdSSe belonging to the 2D monoclinic (oblique) structure but characterized by the same side view environment as the 1T phase. All three structures demonstrate a semimetallic behavior with a non zero density of states (DOS) at the Fermi level

Nanorods of pure and Mn doped ZnO were synthesized by precipitation method. Thick films of synthesized materials were prepared by screen printing method. Structural and morphological characterizations were carried out by XRD, FESEM and EDAX. The gas sensing characteristics of prepared thick films were checked for different gases i.e. H2S, CO2 and LPG. XRD analysis showed hexagonal wurtzite structure

Two dimensional (2D) superconductors are important both for the basic understanding of paring mechanism and potential applications in nanosuperconducting quantum interference devices. In this work, we explore the phonon-mediated superconductivity of hole doped and Lithium-deposited monolayer BC2N by first-principles calculations. Our results reveal that the hole doped planar BC2N can not superconduct

A doubly modulated metamaterial absorber is proposed and numerically verified. An absorption peak (P1, 95%) is achieved at resonance wavelength 1.6μm at room temperature, which is derived from two strong local surface plasmas (LSP) modes excited on central metal particle. S-parameter extracted results show that near ideally impedance matching condition is achieved at resonance wavelength 1.6μm between

To gain valuable insights into the applicability of Pd-decorated carbon nitride (C3N) monolayer as chemical gas sensor for the detection of CH4 and CO2 molecules, we have explored the adsorption properties of Pd-C3N nanosheets for detection of methane (CH4) and carbon dioxide (CO2) molecules. Firstly, the stability of Pd binding to the C3N monolayer was probed based on the adsorption energy analysis

Magnetic anisotropy (MA) in magnetic multilayer structures plays a critical role in the design of future spintronic and magnetic devices. This property is more important for structures with a thickness of few angstroms, such as few-layer two-dimensional materials. Here, we determined the variation in the interface MA in mono- and bi-layer Co/phosphorene heterostructures via first-principles density

In this paper, we analyze the robustness of the quantum correlations of the nearest neighbor and the next-to-neighbor qubits in the intrinsic noise model, that describes the dynamics of the decoherence for a system formed by 3-qubit Heisenberg XY chain. The effects of the uniformity and the inhomogeneity of the applied magnetic field are considered. The generated mixedness entropy, the robustness of

l-Cyteine is a form of amino acid found in human body. Retaining the exact quantity of l-Cyteine is important for better functioning of the body. A novel hybrid TiO2 nanostructure (H-TNTs) was prepared on both sides of Ti sheet using the first-step anodization in used (residual) ethylene glycol (EG) based electrolyte. The H-TNTs was explored as an enzyme-free electrochemical biosensor for the detection

The polarizability of electrons in CdTe/CdxHg1−xTe/CdTe quantum wells is studied. It is shown that polarizability in the quantum well without cadmium is negative, i.e., the displacement of an electron and hole in the main subbands of spatial quantization in an electric field applied perpendicularly to the quantum well plane is opposite to the force acting on it. It is predicted that the negative polarizability

Single Tin Dioxide nanowire (SnO2NW) field-effect-transistors (FET) devices have been a great candidate to build electronic circuits, as chemical and physical sensors and study low dimensional properties and related effects. Ambipolarity is one of those effects that may direct its use for specific purposes, where a controllable separated unipolar mode can be achieved in one single device. SnO2NWs grown

This paper presents the results of a systematic study of the interaction between the carbon monoxide (CO) molecule and pure or Fe-doped Stone-Wales defected graphene (SW-G) using first-principles density functional theory calculations. The calculations revealed that the Fe atom could be stably doped into the SW-G to build the Fe-SW-G. Further study showed that the CO molecule could only be adsorbed

We describe the nonlocal heat transport across a thin film in contact with two thermal baths using discrete variable model. The effective thermal conductivities, the boundary temperature jumps, the steady-state heat flux, and the internal temperature gradient are calculated analytically as functions of the film size and the boundary resistances. As the system size decreases, all the parameters demonstrate

In this paper, the optimization, elaboration and characterization of an efficient spectral beam splitter based on a simple RF sputtered ITO/Ag/ITO (IAI) ultra-thin multilayer structure are presented. An experimental investigation assisted by Genetic Algorithm (GA) metaheuristic optimization was carried out to achieve high-performance spectral splitter for tandem solar cell applications. The RF magnetron

Overcoming the performance limits encountered with the conventional nanoscale transistors while simplifying the fabrication process is an objective that can give a new impulses to the modern nanoelectronics. A novel band-to-band tunneling junctionless carbon nanotube field-effect transistor, endowed with a lightly doped pocket underneath the coaxial gate, is computationally proposed herein. The quantum

Defect-induced magnetism in two-dimensional materials continues to attract attention due to potential applications in spintronics. Using density-functional theory (DFT) approach, we report on the magnetization in graphene containing carbon vacancy defects, i.e., nanoporous graphene. We consider single nanopores consisting of up to ten vacancies and interacting nanopores consisting in vacancy pairs

Herein, the hydrothermal route has been explored to design a novel network of molybdenum sulfide (MoS2) nanorods/reduced graphene oxide (rGO) by varying wt% of MoS2 (10–30 wt%) for the highly stable and efficient electrochemical energy conversion applications involving dye sensitized solar cells (DSSCs); and direct methanol fuel cells (DMFCs). The MoS2/rGO nanohybrids network has been systematically

A comprehensive study of excitonic complexes in high-quality GaAs quantum wells has been performed. The polarization-resolved photoluminescence results show exciton, biexciton, and trion emissions tuned by temper- ature, excitation power, and by an external magnetic field. Excitons and biexcitons show important differences in their dependence on the external field. While the Zeeman splitting of biexcitons

A semiconductor heterostructure made with two asymmetric coupled self-assembled quantum dots (ACSAQDs) has been studied. Such a structure can serve as a spin based quantum dot qubit which is an important manufacture for quantum communication and quantum information processing. The shape of the confinement potential, the used semiconductor materials and the size of the investigated quantum dots have

In this work, we propose a tunable hyperbolic graphene-polar dielectric metamaterial in the far-infrared range. Here, we employ LiF as a strongly dispersive photonic material which can support surface plasmon polariton within its polaritonic gap. The proposed metamaterial has been analyzed using effective medium approximation (EMA) and transfer matrix method (TMM). It is found that the characterization

A theoretical model is proposed for observing Fano resonances in a two-well structure in an electric field directed along the growth axis of the structure. Theoretical considerations make it possible to estimate the probability of photoionization of the structure depending on the values of the varied structural parameters. Comparison of the curves of the dependences of resonant photoionization on energy

Due to the edge states of zigzag graphene nanoribbon (ZGNR), heterojunctions of p- and n-type doped ZGNRs with either high rectification ratios or high spin-filter efficiencies are constructed. Four ZGNR-based heterojunctions are designed theoretically by replacing the edge carbon atoms of two ZGNR electrodes with boron atoms and nitrogen atoms, respectively. The electron-transport properties and the

Hydrogen storage on the Ca-decorated defective boron nitride nanosheets (BNNSs) is investigated by first-principle calculation based on density functional theory. Four types of experimentally available defects, B vacancy (VB), N vacancy (VN), Stone-Wales defect (SW) and B–N divacancy (VNB), are considered. It is found that the binding energy of Ca atom on BNNSs with VN and SW defects is smaller than

The influence of the spin Nernst effect on the quantum entanglement is investigated on the two-dimensional antiferromagnetic model in the checkerboard lattice, in the presence of a Dzyaloshinskii-Moriya interaction, using linear spins waves. We present results of the effect of the Dzyaloshinskii-Moriya interaction, next-nearest neighboring interactions and inter-layer coupling as well as variation

A continuum model of kp-type for the approximate calculation of the characteristics of electromagnetic waves propagating in an almost circular (azimuthally symmetric), closely packed bundle of parallel, identical, and metal carbon nanotubes (CNTs) yields results in reasonably good agreement with the equivalent-multishell approach and with a many-body technique, for infinitely long bundles when the

In this work, we predict two novel ternary graphene-like structures, B4P4C4 and B2P2C8 monolayer. Their structural, mechanical and electronic properties are systematically investigated based on first-principles methods. The results show that the intrinsic and the strained materials possess excellent dynamic, thermal and mechanical stability, which provide the possibility for experimental preparation

Non-equilibrium green's function fromalism combined with density functional theory is used to investigate the photogalvanic effect of chromium (Cr)-doped monolayer molybdenum disulfide (MoS2) from first principles. Since the Cr-doped monolayer MoS2 belongs to the C2v point group which is non-inversion symmetric, the photocurrent can be generated at zero bias when irradiated by linearly or circularly

Silicon carbide nanotubes (SiCNTs) have attracted extensive scientific and commercial interest due to their excellent properties. Based on the first principles, the lattice and energy band structure of group III element-doped SiCNTs are studied, it is found that when the electronegativity of the doped atoms is less than that of the surrounding atoms, except for an acceptor energy level near the top

The investigations of lattice thermal conductivity of few layer black phosphorus show the onset of anisotropic thermal conductivity cross-over between zigzag and armchair direction in the low temperature regime (~25K−40K). For the first time, we address anisotropic-isotropic-low anisotropic transition regimes of thermal conductivity in black phosphorus and discuss the influence of phonon-boundary,

Within the framework of Maxwell's equation we have studied light propagation through a finite heterostructure composed of a pair of bilayers with metamaterial/nonlinear Kerr slabs, with the inclusion of an air defect layer between them. The defect layer gives rise to modes, within the plasmon polariton gap, which are the subject of the present investigation. In this way, the number of modes, their

The Majorana-induced Andreev reflection is theoretically investigated, by considering the case of ferromagnetic lead to couple to it via one quantum dot. We find that for the ferromagnetic lead, the Majorana zero mode (MZM) still causes the resonant Andreev reflection at the low-bias limit, even when finite Zeeman splitting appears in the quantum dot. However, the magnetoresistance exhibits interesting

Superlattices comprising of 10 layers of La0.7Ca0.3MnO3 (LCMO, thickness ≈ 8.8 nm) and Pr0.58Ca0.42MnO3 (PCMO, thickness ≈ 4.4 nm) with layer periodicity of ≈ 13.2 nm have been grown by RF magnetron sputtering on (001) oriented LaAlO3 substrates. These superlattices show strong magnetic anisotropy with the easy magnetic axis lying in the plane and hard axis along the normal to the layers. The in-situ

This paper emphasizes on III-V material based inverted metamorphic triple junction (3J IMM) solar cell as an alter-native to 3J lattice-matched InGaP/GaAs/Ge design (3J LM). 1-sun AM0 efficiency is obtained to be 7% higher for the proposed 3J IMM InGaP/GaAs/In0.30Ga0.70As design compared to the experimental 3J LM solar cell. The mi- nority carrier lifetime as a function of threading dislocation density

We investigate here the magneto-transport properties of a 10 nm-wide p-type PbTe single quantum well doped with BaF2 as a function of temperature in the presence and absence of infrared light. Magnetoresistance measurements indicated the presence of Shubnikov-de Haas oscillations that are slightly altered at illuminated conditions. The fast Fourier transform analysis showed that, in dark conditions

The spin fields of the ground state of the two-dimensional quantum rings with Rashba and Dresselhaus spin-orbit couplings are studied and compared with our analysis of the one-dimensional model. The topological charge of the spin field varies periodically due to the step-like change of the angular momentum with an increase of the magnetic field which is perpendicular to the ring. We also demonstrate