Authors:Mehmet Isik, Nizami Gasanly Abstract: Modern Physics Letters B, Ahead of Print. Optical properties of Ga2SeS crystals grown by Bridgman method were investigated by transmission, reflection and ellipsometry measurements. Analysis of the transmission and reflection measurements performed in the wavelength range of 400–1100 nm at room temperature indicated the presence of indirect and direct transitions with 2.28 eV and 2.38 eV band gap energies. Ellipsometry measurements were carried out in the 1.2–6.0 eV spectral region to get information about optical constants, real and imaginary parts of the pseudodielectric function. Moreover, the critical point (CP) analysis of the second derivative spectra of the pseudodielectric constant in the above band gap region was accomplished. The analysis revealed the presence of five CPs with energies of 3.87, 4.16, 4.41, 4.67 and 5.34 eV. Citation: Modern Physics Letters B PubDate: Wed, 03 Jun 2015 03:21:26 GMT DOI: 10.1142/S0217984915500888

Authors:Furkan Dincer, Muharrem Karaaslan, Emin Unal, Oguzhan Akgol, Cumali Sabah Abstract: Modern Physics Letters B, Ahead of Print. We demonstrate numerically and experimentally chiral metamaterials (MTMs) based on gammadion-bilayer cross-wires that uniaxially create giant optical activity and tunable circular dichroism as a result of the dynamic design. In addition, the suggested structure gives high negative refractive index due to the large chirality in order to obtain an efficient polarization converter. We also present a numerical analysis in order to show the additional features of the proposed chiral MTM in detail. Therefore, a MTM sensor application of the proposed chiral MTM is introduced and discussed. The presented chiral designs offer a much simpler geometry and more efficient outlines. The experimental results are in a good agreement with the numerical simulation. It can be seen from the results that, the suggested chiral MTM can be used as a polarization converter, sensor, etc. for several frequency regimes. Citation: Modern Physics Letters B PubDate: Wed, 03 Jun 2015 03:21:25 GMT DOI: 10.1142/S0217984915500876

Authors:Ruguang Zhou Abstract: Modern Physics Letters B, Ahead of Print. A hierarchy of super AKNS equations associated with a [math] matrix-valued spectral problem is derived. It is shown that each equation in the hierarchy is bi-super Hamiltonian. Moreover, a new finite dimensional super Hamiltonian system (FDSHS), together with its Lax representation, r-matrix and conversed integrals of motion, is obtained from the spectral problem by binary nonlinearization. Citation: Modern Physics Letters B PubDate: 2015-07-22T02:22:26Z DOI: 10.1142/S0217984915501262

Authors:Liqiang Feng, Hang Liu, Tianshu Chu Abstract: Modern Physics Letters B, Ahead of Print. A promising method to generate the attosecond XUV sources from the high-order harmonic has been theoretically presented by controlling the polarized gating two-color chirped pulse. The results show that with the introduction of the chirps, the harmonic has been remarkably extended. Moreover, the harmonic interferences are very sensitive to the polarization angle between the two lasers. Particularly, when the polarization angle is equal to [math], the supercontinuum with a single quantum path contribution is achieved, and a series of isolated attosecond pulses with the duration of 33 as are directly obtained. Further, by testing the influences of other laser parameters on the supercontinuum, we found that this polarized two-color chirped scheme can also be achieved in the multi-cycle pulse region, which is much better for experimental realization. Citation: Modern Physics Letters B PubDate: 2015-07-22T02:22:25Z DOI: 10.1142/S0217984915501110

Authors:Muhammad Zaka Ansar, Shahid Atiq, Saira Riaz, Shahzad Naseem, Shahid M. Ramay, Asif Mahmood Abstract: Modern Physics Letters B, Ahead of Print. In recent years, use of magnetic nanoparticles in biomedical applications has increased tremendously. In particular, magnetite (Fe3O4) nanoparticles being highly biocompatible are rated very high due to their potential applications in biomedicines, for instance in anticancer drug delivery. In this work, the Fe3O4 nanoparticles have been synthesized using a novel sol–gel based autocombustion technique. The crystal structure of the Fe3O4 phase was confirmed by the data obtained from X-ray diffraction. Scherrer’s formula was employed to estimate the crystallite size of the Fe3O4 nanoparticles. The structural morphology, investigated by using a scanning electron microscopy (SEM), revealed well-dispersed and uniform sized grains in the sample prepared using enhanced fuel concentration. A vibrating sample magnetometer (VSM) was employed to investigate the magnetic characteristics of the samples which confirmed the superparamagnetic nature of the Fe3O4 samples, essentially required for cancer treatment. These nanoparticles could further be modified and functionalized by suitable polymers to achieve better biocompatibility before being injected into the diseased cells. Citation: Modern Physics Letters B PubDate: 2015-07-22T02:22:21Z DOI: 10.1142/S0217984915501225

Authors:Yuzhen Chai, Chunyan Wu, Dongxi Li Abstract: Modern Physics Letters B, Ahead of Print. We investigate coherence resonance (CR) in the FitzHugh–Nagumo (FHN) neurons models driven by bounded noise. By considering the coefficient of coherence resonance as a ratio, it is numerically demonstrated that bounded noise can cause CR by adjusting either the intensity of bounded noise or its frequency. When the intensity and frequency of bounded noise take certain limited values respectively, the strongest CR phenomenon is produced. Citation: Modern Physics Letters B PubDate: 2015-07-22T02:22:18Z DOI: 10.1142/S0217984915501213

Authors:Sanjun Wang, Xueqing Wang, Jinming Li, Yu Jia, Fei Wang Abstract: Modern Physics Letters B, Ahead of Print. Using density functional theory combined GGA[math]+[math]U method, the structural, electronic and optical properties of rare earth Er substituted Al atom (Er[math]) and its complex with neighboring N vacancy (Er[math]-V[math]) in wurtzite AlN were investigated, respectively. Calculated results show that both defects induced quite localized Er-[math] related defect donor levels in the band gap but had few effects on host electronic structures. Moreover, the calculated complex dielectric functions and other optical constants show that these two defects show clear bulk optical properties, only a small peak near the redshift edge appears for the complex defect. These results show that Er dopant AlN should be a good optical material candidate for optoelectronics application. Citation: Modern Physics Letters B PubDate: 2015-07-22T02:22:18Z DOI: 10.1142/S0217984915501146

Authors:Zheng-Zhe Lin Abstract: Modern Physics Letters B, Ahead of Print. By a tight-binding model, the interaction between linear atomic C chains (LACCs) and short laser pulses was investigated. LACCs were proposed to be used as a medium of laser whose wavelength can be continuously tuned in a range of 321–785[math]nm. This data should be more accurate than the previous result [Europhys. Lett. 97 (2012) 27006] because pure density functional theory calculation always underestimates the band gap. According to the tight-binding model, the lifetime of conduction band (CB) bottom is about 1.9–2.3[math]ns. The electrons pumped into the CB will quickly fall to the band bottom in a time of ps due to electron–phonon interactions. The above results indicate that LACCs are suitable for laser medium. By [math] dichromatic laser pulses, photocurrents can be generated in LACCs, which can be applied as light-controlled signals. Citation: Modern Physics Letters B PubDate: 2015-07-22T02:22:17Z DOI: 10.1142/S0217984915501080

Authors:P. K. Das, Prasanta Haldar Abstract: Modern Physics Letters B, Ahead of Print. An experimentally realizable scheme is considered for manipulating quantum states using a general superposition (SUP) of products of interacting annihilation and creation operators. Application of such an operation on states with classical features introduces strong nonclassicality. This provides the possibility of engineering quantum states with nonclassical features. Citation: Modern Physics Letters B PubDate: 2015-07-22T02:22:16Z DOI: 10.1142/S0217984915501250

Authors:Vincenzo Molinari, Barry D. Ganapol, Domiziano Mostacci Abstract: Modern Physics Letters B, Ahead of Print. The Sutherland approximation to the van der Waals forces is applied to the derivation of a self-consistent Vlasov-type field in a liquid filling a half space, bordering vacuum. The ensuing Vlasov equation is then derived, and solved to predict the behavior of the density at and in the vicinity of the liquid-vacuum interface. A numerical solution to the Vlasov equation is also produced and the density profile shown and discussed. Citation: Modern Physics Letters B PubDate: 2015-07-22T02:22:15Z DOI: 10.1142/S0217984915501122

Authors:Zhi-Xin Li, Cheng-Hong Yin, Xiu-Yun Zhu Abstract: Modern Physics Letters B, Ahead of Print. On the basis of Lee–Low–Pines unitary transformation, the influence of Rashba spin-orbit (RSO) interaction and Zeeman splitting on the ground state energy of polaron in an asymmetric quantum dot (AQD) is studied by using the variational method of Pekar type. The variations of the absolute ratios of the Zeeman splitting energy and the RSO coupling energy to the ground state energy of polaron with the transverse confinement length (TCL) and the longitudinal confinement length (LCL) of AQD and the magnetic field adjusting length (MFAL) are derived when the RSO interaction and the Zeeman splitting are taken into account. We find the influences of the Zeeman splitting energy and the RSO coupling energy on the ground state energy of a polaron are more dominant when the values of the TCL and the LCL are small. The absolute ratio of the Zeeman splitting energy to the ground state energy rapidly decreases with increasing the MFAL and the absolute ratio of the RSO coupling energy to the ground state energy slowly decreases with increase in MFAL when [math], whereas the absolute ratio of the RSO coupling energy to the ground state energy rapidly increases with increase in MFAL when [math]. The above results can be attributed to the interesting quantum size confining and spin effects. Citation: Modern Physics Letters B PubDate: 2015-07-22T02:22:12Z DOI: 10.1142/S0217984915501249

Authors:Shin-Hyung Song, Woo Chun Choi Abstract: Modern Physics Letters B, Ahead of Print. Mechanical micromachining is a powerful and effective way for manufacturing small sized machine parts. Even though the micromachining process is similar to the traditional machining, the material behavior during the process is much different. In particular, many researchers report that the basic mechanics of the work material is affected by microstructures and their crystallographic orientations. For example, crystallographic orientations of the work material have significant influence on force response, chip formation and surface finish. In order to thoroughly understand the effect of crystallographic orientations on the micromachining process, finite-element model (FEM) simulating orthogonal cutting process of single crystallographic material was presented. For modeling the work material, rate sensitive single crystal plasticity of face-centered cubic (FCC) crystal was implemented. For the chip formation during the simulation, element deletion technique was used. The simulation model is developed using ABAQUS/explicit with user material subroutine via user material subroutine (VUMAT). Simulations showed that variation of the specific cutting energy at different crystallographic orientations of work material shows significant anisotropy. The developed FEM model can be a useful prediction tool of micromachining of crystalline materials. Citation: Modern Physics Letters B PubDate: 2015-07-22T02:22:12Z DOI: 10.1142/S0217984915501195

Authors:Jin Wen, Haiwei Fu Abstract: Modern Physics Letters B, Ahead of Print. A scheme to enhance the efficiency and number of the cascaded four-wave mixing (FWM) products in As2S3 chalcogenide planar waveguide is proposed and investigated numerically. Through introducing the optical feedback cavity and Mach–Zehnder interferometer, the modulated broadband cascaded FWM products can be obtained based on the high nonlinear As2S3 chalcogenide planar waveguide. The numerical results show that the bandwidth of the modulated cascaded FWM is increased and the number of cascaded FWM products is improved compared with the single pass way of generating cascaded FWM products. Moreover, the feedback ratio plays an important role in the modulated cascaded FWM. This research can find important potential applications in nonlinear optics and integrated optics. Citation: Modern Physics Letters B PubDate: 2015-07-22T02:22:12Z DOI: 10.1142/S0217984915501158

Authors:Ting Ouyang, Mianyu Xie, Yunfeng Shi, Bing Chen, Yu Lan, Song Yue Abstract: Modern Physics Letters B, Ahead of Print. In this study, single phase cobalt disulfide (CoS2) was synthesized by temperature-controlled solid state hybrid microwave heating. The structure, composition and morphology of the obtained samples were studied using X-ray diffraction (XRD), scanning electron spectroscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and high resolution transmission electron microscopy (HRTEM), respectively. The loose CoS2 polycrystalline precursor was then hot pressed to dense bulk sample. The subsequent transport and magnetic properties measurements reveal the ferromagnetic Curie temperature at the magnetic transition near 128[math]K. These results suggest that the magnetic transition in CoS2 is susceptible to the preparation conditions and the microstructure of the samples. Citation: Modern Physics Letters B PubDate: 2015-07-22T02:22:11Z DOI: 10.1142/S0217984915501201

Authors:Huan Liu, Xianguo Geng Abstract: Modern Physics Letters B, Ahead of Print. A hierarchy of new nonlinear evolution equations associated with [math] matrix spectral problems are proposed, which is a naturally integrable extension of the TD hierarchy. It is shown that all nonlinear evolution equations in the hierarchy have generalized bi-Hamiltonian structures with the help of the trace identity. Moreover, the infinite sequence of conserved quantities of the first nontrivial equation in the hierarchy is constructed by means of spectral parameter expansion. Citation: Modern Physics Letters B PubDate: 2015-07-22T02:22:10Z DOI: 10.1142/S021798491550116X

Authors:Elham N. Afshar, Georgi Xosrovashvili, Rasoul Rouhi, Nima E. Gorji Abstract: Modern Physics Letters B, Ahead of Print. In recent years, nanostructure materials have opened a promising route to future of the renewable sources, especially in the solar cells. This paper considers the advantages of nanostructure materials in improving the performance and stability of the solar cell structures. These structures have been employed for various performance/energy conversion enhancement strategies. Here, we have investigated four types of nanostructures applied in solar cells, where all of them are named as quantum solar cells. We have also discussed recent development of quantum dot nanoparticles and carbon nanotubes enabling quantum solar cells to be competitive with the conventional solar cells. Furthermore, the advantages, disadvantages and industrializing challenges of nanostructured solar cells have been investigated. Citation: Modern Physics Letters B PubDate: 2015-07-14T11:11:48Z DOI: 10.1142/S0217984915501183

Authors:Hai-Xia Dong, Bai-Hua Gong, Dang-Qi Fang, Yang Zhang, Er-Hu Zhang, Sheng-Li Zhang Abstract: Modern Physics Letters B, Ahead of Print. The atomic structure and edge state of zigzag carbon nanoscrolls (ZCNSs) are investigated using first-principles calculations based on density functional theory. The results show a non-monotonic dependence of the total energy of ZCNS on the surface curvature due to a competition between the elasticity and the van der Waals interactions in a scroll. The edge states can be tuned by using different forms of edge hydrogenation and inner radius. It is found that the edge state range of monohydrogenated ZCNSs is smaller than that of monohydrogenated zigzag-edged graphene nanoribbons (ZGNRs), which is also verified using the tight-binding approximation. With the different edge hydrogenations, ZCNSs prefer the [math] hybridization more than the [math] one. Our present study could suggest the possibility of adjusting the electronic properties of ZCNSs and may provide potential applications in the electronic devices. Citation: Modern Physics Letters B PubDate: 2015-07-14T11:11:47Z DOI: 10.1142/S0217984915501109

Authors:Xiaojiao Zhang, Keqiu Chen, Mengqiu Long, Jun He, Yongli Gao Abstract: Modern Physics Letters B, Ahead of Print. The electronic transport properties of molecular devices constructed by conjugated molecular wire tetrathiafulvalene (TTF) have been studied by applying nonequilibrium Green’s functions in combination with the density-functional theory. Two molecular junctions with different wire lengths have been considered. The results show that the current–voltage curves of TTF devices can be modulated by the length of the molecular wire and negative differential resistance behaviors are observed in these systems. The mechanisms have been proposed for the length effect and negative differential resistance behavior. Citation: Modern Physics Letters B PubDate: 2015-07-14T11:11:45Z DOI: 10.1142/S0217984915501067

Authors:Hossein Jafarzadeh, Elnaz Ahmadi Sangachin, Seyyed Hossein Asadpour Abstract: Modern Physics Letters B, Ahead of Print. In this paper, we propose a novel scheme for controlling the group velocity of transmitted and reflected pulse from defect medium doped with four-level [math] quantum dot nanostructure. Quantum dot nanostructure is designed numerically by Schrödinger and Poisson equations which solve self consistently. By size control of quantum dot and external voltage, one can design a four-level quantum dot with appropriate energy levels which can be suitable for controlling the group velocity of pulse transmission and reflection from defect slab with terahertz signal field. It is found that in the presence and absence of terahertz signal field the behaviors of transmission and reflection pulses are completely different. Moreover, it is shown that for strong terahertz signal field, by changing the thickness of the slab, simultaneous peak and dip for transmission and reflection pulse are obtained. Citation: Modern Physics Letters B PubDate: 2015-07-14T11:11:27Z DOI: 10.1142/S0217984915501043

Authors:Desmond A. Johnston, Marco Mueller, Wolfhard Janke Abstract: Modern Physics Letters B, Ahead of Print. The purely plaquette 3D Ising Hamiltonian with the spins living at the vertices of a cubic lattice displays several interesting features. The symmetries of the model lead to a macroscopic degeneracy of the low-temperature phase and prevent the definition of a standard magnetic order parameter. Consideration of the strongly anisotropic limit of the model suggests that a layered, “fuki-nuke” order still exists and we confirm this with multi-canonical simulations. The macroscopic degeneracy of the low-temperature phase also changes the finite-size scaling corrections at the first-order transition in the model and we see this must be taken into account when analyzing our measurements. Citation: Modern Physics Letters B PubDate: 2015-07-14T11:11:20Z DOI: 10.1142/S0217984915501092

Authors:Yu-Xing Xi, Yan-Xia Huang Abstract: Modern Physics Letters B, Ahead of Print. The quantum teleportation via thermally entangled states of three-qubit Heisenberg spin chains with Dzyaloshinsky–Moriya (DM) interactions under a homogeneous magnetic field has been investigated. It is found that average fidelity and critical temperature depend on not only temperature, magnetic field, but also coupling coefficients, and DM interactions. What is more, we also find that average fidelity has little to do with entanglement. Citation: Modern Physics Letters B PubDate: 2015-07-14T11:11:14Z DOI: 10.1142/S0217984915501079

Authors:Haojiang Zhao, Rongqiang Liu, Chuang Shi, Hongwei Guo, Zongquan Deng Abstract: Modern Physics Letters B, Ahead of Print. Longitudinal vibration of thin phononic crystal plates with a hybrid square-like array of square inserts is investigated. The plane wave expansion method is used to calculate the vibration band structure of the plate. Numerical results show that rotated square inserts can open several vibration gaps, and the band structures are twisted because of the rotation of inserts. Filling fraction and material of the insert affect the change law of the gap width versus the rotation angles of square inserts. Citation: Modern Physics Letters B PubDate: 2015-07-14T11:11:10Z DOI: 10.1142/S0217984915501055

Authors:Jinhui Zhai, Jinguang Zhai, Ajun Wan Abstract: Modern Physics Letters B, Ahead of Print. The electronic and optical properties of zinc-blende [math] have been investigated using first principles calculations based on the density functional theory (DFT). The obtained band gap of [math]– [math] is 2.30 eV by means of Heyd–Scuseria–Ernzerhof (HSE) functional. We have discussed the energy-dependent optical functions including dielectric constants, refractive index, absorption, reflectivity, and energy-loss spectrum in detail. The results reveal that [math]– [math] has a higher static dielectric constant compared with that of [math]– [math]. The optical functions are mainly associated with the interband transitions from the occupied valence bands (VBs) [math] and [math] states to [math], [math] and [math] states of the unoccupied conduction bands (CBs). Citation: Modern Physics Letters B PubDate: 2015-07-14T11:11:09Z DOI: 10.1142/S0217984915501031

Authors:Jian-Min Tu, Shou-Fu Tian, Mei-Juan Xu, Pan-Li Ma Abstract: Modern Physics Letters B, Ahead of Print. In this paper, a [math]-dimensional generalized variable-coefficient Sawada–Kotera (gvcSK) equation is investigated, which describes many nonlinear phenomena in fluid dynamics and plasma physics. Based on the properties of binary Bell polynomials, we present a Hirota’s bilinear equation to the gvcSK equation. By virtue of the Hirota’s bilinear equation, we obtain the N-soliton solutions and the quasi-periodic wave solutions of the gvcSK equation, which can be reduced to the ones of several integrable equations such as Sawada–Kotera, modified Caudrey–Dodd–Gibbon–Sawada–Kotera, isospectral BKP equations and etc. Furthermore, we obtain the relationship between the soliton solutions and periodic solutions by considering the asymptotic properties of the periodic solutions. Citation: Modern Physics Letters B PubDate: 2015-07-10T08:47:05Z DOI: 10.1142/S0217984915501018

Authors:Mikhail B. Belonenko, Natalia N. Konobeeva, Elena N. Galkina Abstract: Modern Physics Letters B, Ahead of Print. Dynamics of few cycle optical pulses in non-Fermi liquid was considered. Energy spectrum of non-Fermi liquid was taken from the AdS/CFT correspondence. Conditions of quasiparticle excitation existence were defined. Non-Fermi liquid parameters impact on the shape of few cycle pulses were estimated. Citation: Modern Physics Letters B PubDate: 2015-07-09T12:11:45Z DOI: 10.1142/S0217984915500967

Authors:Hai-Bin Wang, Zhong-Xiang Xie, Xia Yu, Yong Zhang, Dan Wang Abstract: Modern Physics Letters B, Ahead of Print. First-principles calculations are performed to study the effect of isotropic stress on the electronic and magnetic properties of cubic bixbyite Indium oxide [math] doped with substitution [math] impurities. In comparison with undoped [math] materials, the defects can induce a spin moment with 2 [math]B when two [math] atoms substitutes for two [math] atoms in the system. In addition, the spin moment remains the same under the condition of strain less than 2%. When the strain is more than 2%, there is a sharp transition to a high-spin magnetic moment with 4 [math]B and it stays in this position with the increase of strain. This high magnetoelastic effect could be utilized to design pressure-tunable spin devices based on [math]-doped [math]. Citation: Modern Physics Letters B PubDate: 2015-07-09T12:11:41Z DOI: 10.1142/S0217984915500992

Authors:Sui-Shuan Zhang, Zong-Yan Zhao, Pei-Zhi Yang Abstract: Modern Physics Letters B, Ahead of Print. The crystal structure, electronic structure and optical properties of [math]-doped [math] with different [math] impurity concentrations were calculated by density function theory within GGA [math]+ [math]U method. The crystal distortion, impurity formation energy, band gap, band width and optical parameter of [math]-doped [math] are closely related with [math] impurity concentration. Based on the calculated results, there are three new impurity energy levels emerging in the band gap of [math]-doped [math], which determine the electronic structure and optical properties. The variations of optical properties induced by [math] doping are predominately determined by the unsaturated impurity states, which are more obvious at higher [math] impurity concentration. In addition, all the doping effects of [math] in both [math]-quartz [math] and [math]-quartz [math] are very similar. According to these findings, one could understand the relationship between nitrogen concentration and optical parameter of [math] materials, and design new optoelectrionic [math]– [math]– [math] compounds. Citation: Modern Physics Letters B PubDate: 2015-07-09T12:11:41Z DOI: 10.1142/S0217984915501006

Authors:Geng Zhang, Di-Hua Sun, Wei-Ning Liu, Hui Liu Abstract: Modern Physics Letters B, Ahead of Print. In this paper, a new car-following model is proposed by considering driver’s desired velocity according to Transportation Cyber Physical Systems. The effect of driver’s desired velocity on traffic flow has been investigated through linear stability theory and nonlinear reductive perturbation method. The linear stability condition shows that driver’s desired velocity effect can enlarge the stable region of traffic flow. From nonlinear analysis, the Burgers equation and mKdV equation are derived to describe the evolution properties of traffic density waves in the stable and unstable regions respectively. Numerical simulation is carried out to verify the analytical results, which reveals that traffic congestion can be suppressed efficiently by taking driver’s desired velocity effect into account. Citation: Modern Physics Letters B PubDate: 2015-07-09T12:11:40Z DOI: 10.1142/S0217984915500979

Authors:Jing-Lin Xiao Abstract: Modern Physics Letters B, Ahead of Print. Under the condition of strong electron–LO–phonon coupling in a [math] quantum pseudodot (QPD) with an applied magnetic field (MF), the eigenenergies and the eigenfunctions of the ground and the first excited states (GFES) are obtained by using a variational method of the Pekar type (VMPT). A single qubit can be realized in this two-level quantum system. The electron’s probability density oscillates in the [math] QPD with a certain period of [math] fs when the electron is in the superposition state of the GFES. The results indicate that due to the presence of the asymmetrical structure in the z direction of the [math] QPD, the electron’s probability density shows double-peak configuration, whereas there is only peak if the confinement is a symmetric structure in the x and y directions of the [math] QPD. The oscillating period is an increasing function of the cyclotron frequency and the polaron radius, whereas it is a decreasing one of the chemical potential of the two-dimensional electron gas and the zero point of the pseudoharmonic potential (PP). Citation: Modern Physics Letters B PubDate: 2015-07-09T12:11:38Z DOI: 10.1142/S0217984915500980

Authors:Zineb Aarizou, Soumia Bahlouli, Mokhtar Elchikh Abstract: Modern Physics Letters B, Ahead of Print. Structural and magnetic properties as well as the electronic structures of [math] Heusler alloys were investigated in the framework of first principle calculation. Using the full-potential linearized augmented plane wave (FP-LAPW) in connection with the generalized gradient approximation (GGA) treatment of exchange-correlation energy, we have performed the structural optimization in the non-magnetic (NM) and three different magnetic configurations: FM, AFM-I and AFM-II. We have found that our two compounds are stable for the AFM-II state, which agree with the available experimental and theoretical results. The exchange constants [math] and [math] as well as the temperature of transition to the paramagnetic state [math] were estimated here by the use of the energy difference method and the mean field approximation. The electronic structure of our compounds in their magnetic state was also studied. The GGA [math]+ [math]U method has also been used to take into account the strong correlations among the d orbitals of [math] and [math] atoms. This has considerably improved both the electronic and magnetic results which became close to the corresponding experimental data. We have finally studied the thermodynamic properties using the quasi-harmonic Debye model as implemented in the Gibbs Program. Citation: Modern Physics Letters B PubDate: 2015-06-25T09:27:03Z DOI: 10.1142/S0217984915500931

Authors:A. Lavagno, D. Pigato, G. Gervino Abstract: Modern Physics Letters B, Ahead of Print. One of the very interesting aspects of high energy heavy-ion collisions experiments is a detailed study of the thermodynamical properties of strongly interacting nuclear matter away from the nuclear ground state. In this direction, many efforts were focused on searching for possible phase transitions in such collisions. We investigate thermodynamic instabilities in a hot and dense nuclear medium where a phase transition from nucleonic matter to resonance-dominated [math]-matter can take place. Such a phase transition can be characterized by both mechanical instability (fluctuations on the baryon density) and by chemical-diffusive instability (fluctuations on the strangeness concentration) in asymmetric nuclear matter. In analogy with the liquid–gas nuclear phase transition, hadronic phases with different values of antibaryon–baryon ratios and strangeness content may coexist. Such a physical regime could be, in principle, investigated in the future high-energy compressed nuclear matter experiments which will make it possible to create compressed baryonic matter with a high net baryon density. Citation: Modern Physics Letters B PubDate: 2015-06-25T09:27:01Z DOI: 10.1142/S021798491550092X

Authors:Zi-Wen Huang, Ji-Xuan Hou, Chun Xie, Hao Zhang Abstract: Modern Physics Letters B, Ahead of Print. We investigated a highly coarse-grained polymer model — hard-sphere (HS) model. This model is characterized by its time-saving computation and strictly guaranteed uncrossability of polymer chains. Regarding the statistical and dynamic properties of HS model, our simulating results perfectly coincide with pre-existing scaling theory. Additionally, we point out that the power exponent of scaling relationship between its relaxation time and chain length is 2.2. Citation: Modern Physics Letters B PubDate: 2015-06-25T09:27:00Z DOI: 10.1142/S0217984915500918

Authors:Fan Yang, Guowu Yang, Yujie Hao, Qingbin Luo, Yuqi Wang Abstract: Modern Physics Letters B, Ahead of Print. This paper presents an analysis method for quantum information protocols based on model checking, with special focus on the quantum privacy comparison (QPC). The security properties of these protocols can be proved but in ways with much difficulty. Here we will discuss a probabilistic model checking tool — PRISM to verify specific properties of QPC protocol with multi-body and PRISM to verify specific properties of quantum private comparison (QPC) protocol with multi-party and d-dimensional entangled states. Citation: Modern Physics Letters B PubDate: 2015-06-25T09:26:58Z DOI: 10.1142/S021798491550089X

Authors:E. Elkoraychy, A. Kotri, M. Mazroui, K. Sbiaai, K. Saadouni Abstract: Modern Physics Letters B, Ahead of Print. In this paper, the dynamic properties of a single adatom subject to a two-dimensional periodic potential of square symmetry are investigated. This problem is addressed through the strong-collision model, where the dynamical interaction of the adatom with the substrate is modeled by well-separated collisions that thermalize the velocity. By means of molecular dynamics simulations, we calculate the jump-length probability distribution and the diffusion coefficient as a function of x–y coupling term and of the collision frequency [math]. Our numerical results show that the x–y coupling always suppresses a large proportion of long jumps, inducing thus a decrease of the diffusion coefficient for all values of [math]. Implications of these findings are briefly discussed. Citation: Modern Physics Letters B PubDate: 2015-06-25T09:26:56Z DOI: 10.1142/S0217984915500906

Authors:G. Subhashree, S. Sankar, R. Krithiga Abstract: Modern Physics Letters B, Ahead of Print. Self-consistent first principles calculations on type II weakly coupled superconducting [math] compounds of A15 phase are performed to understand their fundamental characteristics of the electronic, thermal and superconducting properties. The bulk modulus [math], Debye temperature [math], density of states (DOS) [math], electron–phonon coupling constant [math], superconducting transition temperature [math], and electronic specific heat coefficient [math] have been computed in terms of the electronic structure results, obtained by using the tight-binding linear muffin-tin orbital method. It is observed that all the three materials have their electronic properties dominated by d-orbital at Fermi energy. Thermal and superconducting properties calculated here are found to corroborate well with the experimental results of literature. Citation: Modern Physics Letters B PubDate: 2015-06-25T09:26:52Z DOI: 10.1142/S0217984915500943

Authors:Le Deng, Li Bin Wang, Jie Ming Qin, Tao Zheng, Jing Ni, Xiao Peng Jia, Hong An Ma Abstract: Modern Physics Letters B, Ahead of Print. A novel chemical alloying method of high-pressure and high-temperature (HPHT) has been used for the synthesis of bulk-skutterudite [math]. Through HPHT method, the synthesis time has been shortened from a few days to 30 min. The samples of [math] skutterudites were synthesized at 1.8–3.3 GPa. We have studied the phase, the microstructure, and the temperature-dependent thermoelectric properties. The Seebeck coefficient, electrical conductivity and thermal conductivity were measured in the temperature range of 295–673 K. As we expected, the thermal conductivity of sample [math] decreased with the increase of the synthetic pressure. A maximal ZT of 0.64 was achieved for the [math] synthesized at 1.8 GPa at 673 K. These results revealed that HPHT method may be helpful for optimizing electrical conductivity and thermal conductivity in a comparatively independent way. Citation: Modern Physics Letters B PubDate: 2015-06-25T09:26:50Z DOI: 10.1142/S0217984915500955