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“Enhanced transmission versus localization of a light pulse by a subwavelength metal slit”. Kukhlevsky SV, Mechler M, Csapo L, Janssens K, Samek O, Physical review : B : condensed matter and materials physics 70, 195428 (2004). http://doi.org/10.1103/PHYSREVB.70.195428
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 3.836
Times cited: 17
DOI: 10.1103/PHYSREVB.70.195428
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“Resonant backward scattering of light by a subwavelength metallic slit with two open sides”. Kukhlevsky SV, Mechler M, Csapó, L, Janssens K, Samek O, Physical review : B : condensed matter and materials physics 72, 165421 (2005). http://doi.org/10.1103/PHYSREVB.72.165421
Abstract: The backward scattering of TM-polarized light by a two-side-open subwavelength slit in a metal film is analyzed. We show that the reflection coefficient versus wavelength possesses a Fabry-Perot-like dependence that is similar to the anomalous behavior of transmission reported in the study [Y. Takakura, Phys. Rev. Lett. 86, 5601 (2001)]. The open slit totally reflects the light at the near-to-resonance wavelengths. In addition, we show that the interference of incident and resonantly backward-scattered light produces in the near-field diffraction zone a spatially localized wave whose intensity is 10103 times greater than the incident wave, but one order of magnitude smaller than the intracavity intensity. The amplitude and phase of the resonant wave at the slit entrance and exit are different from that of a Fabry-Perot cavity.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 3.836
Times cited: 7
DOI: 10.1103/PHYSREVB.72.165421
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“Angular melting scenarios in binary dusty-plasma Coulomb balls : magic versus normal clusters”. Apolinario SWS, Aguiar JA, Peeters FM, Physical review : E : statistical, nonlinear, and soft matter physics 90, 063113 (2014). http://doi.org/10.1103/PhysRevE.90.063113
Abstract: Molecular-dynamic simulations were performed in order to investigate the melting processes of isotropically confined binary systems. We considered two species of particles, which differ by their amount of electric charge. A Lindemann type of criterion was used to determine the angular melting temperature. We demonstrate that the magic-to-normal cluster transition can evolve in two distinct ways, that is, through a structural phase transition of the first order or via a smooth transition where an increase of the shells' width leads to a continuous decreasing mechanical stability of the system. Moreover, for large systems, we demonstrate that the internal cluster exerts a minor effect on the mechanical stability of the external shell. Furthermore, we show that highly symmetric configurations, such as those found for multiple ring structures, have large mechanical stability, i.e., high angular melting temperature.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 1
DOI: 10.1103/PhysRevE.90.063113
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“Bilayer crystals of charged magnetic dipoles : structure and phonon spectrum”. Ramos IRO, Ferreira WP, Munarin FF, Farias GA, Peeters FM, Physical review : E : statistical, nonlinear, and soft matter physics 85, 051404 (2012). http://doi.org/10.1103/PhysRevE.85.051404
Abstract: We study the structure and phonon spectrum of a two-dimensional bilayer system of classical charged dipoles oriented perpendicular to the plane of the layers for equal density in each layer. This system can be tuned through six different crystalline phases by changing the interlayer separation or the charge and/or dipole moment of the particle. The presence of the charge on the dipole particles is responsible for the nucleation of five staggered phases and a disordered phase which are not found in the magnetic dipole bilayer system. These extra phases are a consequence of the competition between the repulsive Coulomb and the attractive dipole interlayer interaction. We present the phase diagram and determine the order of the phase transitions. The phonon spectrum of the system was calculated within the harmonic approximation, and a nonmonotonic behavior of the phonon spectrum is found as a function of the effective strength of the interparticle interaction. The stability of the different phases is determined.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 8
DOI: 10.1103/PhysRevE.85.051404
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“Diffusion in a quasi-one-dimensional system on a periodic substrate”. Carvalho JCN, Nelissen K, Ferreira WP, Farias GA, Peeters FM, Physical review : E : statistical, nonlinear, and soft matter physics 85, 021136 (2012). http://doi.org/10.1103/PhysRevE.85.021136
Abstract: The diffusion of charged particles interacting through a repulsive Yukawa potential, exp(-r/lambda)/r, confined by a parabolic potential in the y direction and subjected to a periodic substrate potential in the x direction is investigated. Langevin dynamic simulations are used to investigate the effect of the particle density, the amplitude of the periodic substrate, and the range of the interparticle interaction potential on the diffusive behavior of the particles. We found that in general the diffusion is suppressed with increasing the amplitude of the periodic potential, but for specific values of the strength of the substrate potential a remarkable increase of the diffusion is found with increasing the periodic potential amplitude. In addition, we found a strong dependence of the diffusion on the specific arrangement of the particles, e. g., single-chain versus multichain configuration. For certain particle configurations, a reentrant behavior of the diffusion is found as a function of the substrate strength due to structural transitions in the ordering of the particles.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 9
DOI: 10.1103/PhysRevE.85.021136
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“Diffusion of interacting particles in discrete geometries: Equilibrium and dynamical properties”. Becker T, Nelissen K, Cleuren B, Partoens B, Van den Broeck C, Physical review : E : statistical, nonlinear, and soft matter physics 90, 052139 (2014). http://doi.org/10.1103/PhysRevE.90.052139
Abstract: We expand on a recent study of a lattice model of interacting particles [Phys. Rev. Lett. 111, 110601 (2013)]. The adsorption isotherm and equilibrium fluctuations in particle number are discussed as a function of the interaction. Their behavior is similar to that of interacting particles in porous materials. Different expressions for the particle jump rates are derived from transition-state theory. Which expression should be used depends on the strength of the interparticle interactions. Analytical expressions for the self-and transport diffusion are derived when correlations, caused by memory effects in the environment, are neglected. The diffusive behavior is studied numerically with kinetic Monte Carlo (kMC) simulations, which reproduces the diffusion including correlations. The effect of correlations is studied by comparing the analytical expressions with the kMC simulations. It is found that the Maxwell-Stefan diffusion can exceed the self-diffusion. To our knowledge, this is the first time this is observed. The diffusive behavior in one-dimensional and higher-dimensional systems is qualitatively the same, with the effect of correlations decreasing for increasing dimension. The length dependence of both the self-and transport diffusion is studied for one-dimensional systems. For long lengths the self-diffusion shows a 1/L dependence. Finally, we discuss when agreement with experiments and simulations can be expected. The assumption that particles in different cavities do not interact is expected to hold quantitatively at low and medium particle concentrations if the particles are not strongly interacting.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 8
DOI: 10.1103/PhysRevE.90.052139
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“Dynamical properties and melting of binary two-dimensional colloidal alloys”. Ramos IRO, Ferreira WP, Munarin FF, Peeters FM, Physical review : E : statistical, nonlinear, and soft matter physics 90, 062311 (2014). http://doi.org/10.1103/PhysRevE.90.062311
Abstract: A two-dimensional (2D) binary colloidal system consisting of interacting dipoles is investigated using an analytical approach. Within the harmonic approximation we obtain the phonon spectrum of the system as a function of the composition, dipole-moment ratio, and mass ratio between the small and big particles. Through a systematic analysis of the phonon spectra we are able to determine the stability region of the different lattice structures of the colloidal alloys. The gaps in the phonon frequency spectrum, the optical frequencies in the long-wavelength limit, and the sound velocity are discussed as well. Using the modified Lindemann criterion and within the harmonic approximation we estimate the melting temperature of the sublattice generated by the big particles.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 4
DOI: 10.1103/PhysRevE.90.062311
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“Dynamics of self-organized driven particles with competing range interaction”. Zhao HJ, Misko VR, Peeters FM, Physical review : E : statistical, nonlinear, and soft matter physics 88, 022914 (2013). http://doi.org/10.1103/PhysRevE.88.022914
Abstract: Nonequilibrium self-organized patterns formed by particles interacting through competing range interaction are driven over a substrate by an external force. We show that, with increasing driving force, the preexisted static patterns evolve into dynamic patterns either via disordered phase or depinned patterns or via the formation of nonequilibrium stripes. Strikingly, the stripes are formed either in the direction of the driving force or in the transverse direction, depending on the pinning strength. The revealed dynamical patterns are summarized in a dynamical phase diagram.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 23
DOI: 10.1103/PhysRevE.88.022914
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“Effect of small amounts of hydrogen added to argon glow discharges: hybrid Monte-Carlo-fluid model”. Bogaerts A, Gijbels R, Physical review : E : statistical, nonlinear, and soft matter physics 65, 056402 (2002). http://doi.org/10.1103/PhysRevE.65.056402
Abstract: A hybrid Monte Carlofluid modeling network is developed for an argon-hydrogen mixture, to predict the effect of small amounts of hydrogen added to a dc argon glow discharge. The species considered in the model include the Ar gas atoms, electrons, Ar+ ions and fast Ar atoms, ArH+, H+, H+2 and H+3 ions, and H atoms and H2 molecules, as well as Ar metastable atoms, sputtered Cu atoms, and the corresponding Cu+ ions. Sixty-five reactions between these species are incorporated in the model. The effect of hydrogen on various calculation results is investigated, such as the species densities, the relative role of different production and loss processes for the various species, the cathode sputtering rate and contributions by different bombarding species, and the dissociation degree of H2 and the ionization degree of Ar and Cu. The calculation results are presented and discussed for 1% H2 addition, and comparison is also made with a pure argon discharge and with only 0.1% H2 addition.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.366
Times cited: 33
DOI: 10.1103/PhysRevE.65.056402
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“Electron anisotropic scattering in gases: a formula for Monte Carlo simulations”. Okhrimovskyy A, Bogaerts A, Gijbels R, Physical review : E : statistical, nonlinear, and soft matter physics 65, 037402 (2002). http://doi.org/10.1103/PhysRevE.65.037402
Abstract: The purpose of this Brief Report is to point out the mistake in a formula for anisotropic electron scattering, previously published in Phys. Rev. A 41, 1112 (1990), which is widely used in Monte Carlo models of gas discharges. Anisotropic electron scattering is investigated based on the screened Coulomb potential between electrons and neutral atoms. The approach is also applied for electron scattering by nonpolar neutral molecules. Differential cross sections for electron scattering by Ar, N2, and CH4 are constructed on the basis of momentum and integrated cross sections. The formula derived in this paper is useful for Monte Carlo simulations of gas discharges.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.366
Times cited: 57
DOI: 10.1103/PhysRevE.65.037402
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“Electron Boltzmann kinetic equation averaged over fast electron bouncing and pitch-angle scattering for fast modeling of electron cyclotron resonance discharge”. Kaganovich I, Misina M, Berezhnoi S, Gijbels R, Physical review : E : statistical, nonlinear, and soft matter physics 61, 1875 (2000). http://doi.org/10.1103/PhysRevE.61.1875
Abstract: The electron distribution function (EDF) in an electron cyclotron resonance (ECR) discharge is far from Maxwellian. The self-consistent simulation of ECR discharges requires a calculation of the EDF on every magnetic line for various ion density profiles. The straightforward self-consistent simulation of ECR discharges using the Monte Carlo technique for the EDF calculation is very computer time expensive, since the electron and ion time scales are very different. An electron Boltzmann kinetic equation averaged over the fast electron bouncing and pitch-angle scattering was derived in order to develop an effective and operative tool for the fast modeling (FM) of low-pressure ECR discharges. An analytical solution for the EDF in a loss cone was derived. To check the validity of the FM, one-dimensional (in coordinate) and two-dimensional (in velocity) Monte Carlo simulation codes were developed. The validity of the fast modeling method is proved by comparison with the Monte Carlo simulations. The complete system of equations for FM is presented and ready for use in a comprehensive study of ECR discharges. The variations of plasma density and of wall and sheath potentials are analyzed by solving a self-consistent set of equations for the EDF.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.366
Times cited: 31
DOI: 10.1103/PhysRevE.61.1875
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“Ground state and normal-mode spectra of a two-dimensional system of dipole particles confined in a parabolic trap”. Munarin FF, Ferreira WP, Farias GA, Peeters FM, Physical review : E : statistical, nonlinear, and soft matter physics 78, 031405 (2008). http://doi.org/10.1103/PhysRevE.78.031405
Abstract: The ordered configurations of a monolayer of interacting magnetic dipoles confined in a circular parabolic potential are investigated as a function of the dipole moment of the particles. Despite the circular confinement, we find very asymmetric ordered structures like chains and Y-shaped configurations when a magnetic field is applied parallel to the plane of the particles. The normal-mode spectrum of the particles and its dependence on the magnetic field and the strength of the dipole moment of the particles are studied. The vibrational and rotational modes of the spectrum, which are associated with the stability of the system, are investigated in detail. The number of particles is varied and we found different ordering of the particles for different values of the dipole moment and the magnetic field. A ring structure with a large number of particles is observed for high values of the dipole moment of the particles.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 5
DOI: 10.1103/PhysRevE.78.031405
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“Interplay of model ingredients affecting aggregate shape plasticity in diffusion-limited aggregation”. Duarte-Neto P, Stosic T, Stosic B, Lessa R, Milošević, MV, Physical review : E : statistical, nonlinear, and soft matter physics 90, 012312 (2014). http://doi.org/10.1103/PhysRevE.90.012312
Abstract: We analyze the combined effect of three ingredients of an aggregation model-surface tension, particle flow and particle source-representing typical characteristics of many aggregation growth processes in nature. Through extensive numerical experiments and for different underlying lattice structures we demonstrate that the location of incoming particles and their preferential direction of flow can significantly affect the resulting general shape of the aggregate, while the surface tension controls the surface roughness. Combining all three ingredients increases the aggregate shape plasticity, yielding a wider spectrum of shapes as compared to earlier works that analyzed these ingredients separately. Our results indicate that the considered combination of effects is fundamental for modeling the polymorphic growth of a wide variety of structures in confined geometries and/or in the presence of external fields, such as rocks, crystals, corals, and biominerals.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 3
DOI: 10.1103/PhysRevE.90.012312
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“Local and fast relaxation phenomena after laser-induced photodetachment in a strongly electronegative rf discharge”. Yan M, Bogaerts A, Gijbels R, Goedheer WJ, Physical review : E : statistical, nonlinear, and soft matter physics 65, 016408 (2002). http://doi.org/10.1103/PhysRevE.65.016408
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.366
Times cited: 2
DOI: 10.1103/PhysRevE.65.016408
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“Magnetic particles confined in a modulated channel : structural transitions tunable by tilting a magnetic field”. Galván Moya JE, Lucena D, Ferreira WP, Peeters FM, Physical review : E : statistical, nonlinear, and soft matter physics 89, 032309 (2014). http://doi.org/10.1103/PhysRevE.89.032309
Abstract: The ground state of colloidal magnetic particles in a modulated channel are investigated as a function of the tilt angle of an applied magnetic field. The particles are confined by a parabolic potential in the transversal direction while in the axial direction a periodic substrate potential is present. By using Monte Carlo simulations, we construct a phase diagram for the different crystal structures as a function of the magnetic field orientation, strength of the modulated potential, and the commensurability factor of the system. Interestingly, we found first-and second-order phase transitions between different crystal structures, which can be manipulated by the orientation of the external magnetic field. A reentrant behavior is found between two-and four-chain configurations, with continuous second-order transitions. Novel configurations are found consisting of frozen solitons of defects. By changing the orientation and/or strength of the magnetic field and/or the strength and periodicity of the substrate potential, the system transits through different phases.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 11
DOI: 10.1103/PhysRevE.89.032309
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“Melting and evaporation in classical two-dimensional clusters confined by a Coulomb potential”. Ferreira WP, Peeters FM, Farias GA, Physical review : E : statistical, nonlinear, and soft matter physics 72, 041502 (2005). http://doi.org/10.1103/PhysRevE.72.041502
Abstract: The thermal properties of a two-dimensional classical cluster of negatively charged particles bound by a punctual positive charge are presented. The melting phenomenon is analyzed and the features which characterize such a solid-liquid transition are highlighted. We found that the presence of metastable states strongly modifies the melting scenario, and that the melting temperature of the system is determined by the height of the saddle point energy separating the ground state and the metastable state. Due to the particular type of confinement potential considered in this paper, we also found that, at sufficiently large temperature, the cluster can become thermally ionized.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 4
DOI: 10.1103/PhysRevE.72.041502
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“Self-assembly of Janus particles confined in a channel”. Sobrino Fernandez M, Misko VR, Peeters FM, Physical review : E : statistical, nonlinear, and soft matter physics 89, 022306 (2014). http://doi.org/10.1103/PhysRevE.89.022306
Abstract: Janus particles present an important class of building blocks for directional assembly. These are compartmentalized colloids with two different hemispheres. Here, we consider a two-dimensional model of Janus disks consisting of a hydrophobic semicircle and an electro-negatively charged one. Placed in a solution, the hydrophobic sides will attract each other while the charged sides will give rise to a repulsive force. Using molecular dynamics simulations, we study the morphology of these particles when confined in a channel-like environment using a one dimensional harmonic confinement potential. The interest to this system is first of all due to the fact that it could serve as a simple model for membrane formation. Indeed, the recently synthesized new class of artificial amphiphiles, known as Janus dendrimers, were shown to self-assemble in bilayer structures mimicking biological membranes. In turn, Janus particles that combine the amphiphilicity and colloidal rigidity serve as a good model for Janus dendrimers. A variety of ordered membrane-like morphologies are found consisting of single and multiple chain configurations with different orientations of the particles with respect to each other that we summarize in a phase diagram.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 11
DOI: 10.1103/PhysRevE.89.022306
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“Single-file and normal diffusion of magnetic colloids in modulated channels”. Lucena D, Galván Moya JE, Ferreira WP, Peeters FM, Physical review : E : statistical, nonlinear, and soft matter physics 89, 032306 (2014). http://doi.org/10.1103/PhysRevE.89.032306
Abstract: Diffusive properties of interacting magnetic dipoles confined in a parabolic narrow channel and in the presence of a periodic modulated (corrugated) potential along the unconfined direction are studied using Brownian dynamics simulations. We compare our simulation results with the analytical result for the effective diffusion coefficient of a single particle by Festa and d'Agliano [Physica A 90, 229 (1978)] and show the importance of interparticle interaction on the diffusion process. We present results for the diffusion of magnetic dipoles as a function of linear density, strength of the periodic modulation and commensurability factor.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 5
DOI: 10.1103/PhysRevE.89.032306
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“Single-file diffusion in periodic energy landscapes : the role of hydrodynamic interactions”. Euán-Díaz EC, Misko VR, Peeters FM, Herrera-Velarde S, Castaneda-Priego R, Physical review : E : statistical, nonlinear, and soft matter physics 86, 031123 (2012). http://doi.org/10.1103/PhysRevE.86.031123
Abstract: We report on the dynamical properties of interacting colloids confined to one dimension and subjected to external periodic energy landscapes. We particularly focus on the influence of hydrodynamic interactions on the mean-square displacement. Using Brownian dynamics simulations, we study colloidal systems with two types of repulsive interparticle interactions, namely, Yukawa and superparamagnetic potentials. We find that in the homogeneous case, hydrodynamic interactions lead to an enhancement of the particle mobility and the mean-square displacement at long times scales as t(alpha), with alpha = 1/2 + epsilon and epsilon being a small correction. This correction, however, becomes much more important in the presence of an external field, which breaks the homogeneity of the particle distribution along the line and, therefore, promotes a richer dynamical scenario due to the hydrodynamical coupling among particles. We provide here the complete dynamical scenario in terms of the external potential parameters: amplitude and commensurability.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 14
DOI: 10.1103/PhysRevE.86.031123
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“Structure and correlations in two-dimensional classical artificial atoms confined by a Coulomb potential”. Ferreira WP, Matulis A, Farias GA, Peeters FM, Physical review : E : statistical, nonlinear, and soft matter physics 67, 046601 (2003). http://doi.org/10.1103/PhysRevE.67.046601
Abstract: The ordering of N equally charged particles (-e) moving in two dimensions and confined by a Coulomb potential, resulting from a displaced positive charge Ze is discussed. This is a classical model system for atoms. We obtain the configurations of charged particles which, depending on the value of N and Z, may result in ring structures, hexagonal-type configurations, and for N/Z approximate to 1 in an inner structure of particles which is separated by an outer ring of particles. For N/Z << 1, the Hamiltonian of the parabolic confinement case is recovered. For N/Z approximate to 1, the configurations are very different from those found in the case of a parabolic confinement potential. A hydrodynamic analysis is presented in order to highlight the correlations effects.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 14
DOI: 10.1103/PhysRevE.67.046601
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“Structure, normal mode spectra, and mixing of a binary system of charged particles confined in a parabolic trap”. Ferreira WP, Munarin FF, Nelissen K, Costa RN, Peeters FM, Farias GA, Physical review : E : statistical, nonlinear, and soft matter physics 72, 021406 (2005). http://doi.org/10.1103/PhysRevE.72.021406
Abstract: We study the mixing of two different kinds of particles, having different charge and/or mass, interacting through a pure Coulomb potential, and confined in a parabolic trap. The structure of the cluster and its normal mode spectrum are analyzed as a function of the ratio of the charges (mass ratio) of the two types of particles. We show that particles are not always arranged in a shell structure. Mixing of the particles goes hand in hand with a large number of metastable states. The normal modes of the system are obtained, and we find that some of the special modes can be tuned by varying the ratio between the charges (masses) of the two species. The degree of mixing of the two type of particles is summarized in a phase diagram, and an order parameter that describes quantitatively the mixing between particles is defined.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 25
DOI: 10.1103/PhysRevE.72.021406
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“Transition from single-file to two-dimensional diffusion of interacting particles in a quasi-one-dimensional channel”. Lucena D, Tkachenko DV, Nelissen K, Misko VR, Ferreira WP, Farias GA, Peeters FM, Physical review : E : statistical, nonlinear, and soft matter physics 85, 031147 (2012). http://doi.org/10.1103/PhysRevE.85.031147
Abstract: Diffusive properties of a monodisperse system of interacting particles confined to a quasi-one-dimensional channel are studied using molecular dynamics simulations. We calculate numerically the mean-squared displacement (MSD) and investigate the influence of the width of the channel (or the strength of the confinement potential) on diffusion in finite-size channels of different shapes (i.e., straight and circular). The transition from single-file diffusion to the two-dimensional diffusion regime is investigated. This transition [ regarding the calculation of the scaling exponent (alpha) of the MSD <Delta x(2)(t)> proportional to t(alpha)] as a function of the width of the channel is shown to change depending on the channel's confinement profile. In particular, the transition can be either smooth (i.e., for a parabolic confinement potential) or rather sharp (i.e., for a hard-wall potential), as distinct from infinite channels where this transition is abrupt. This result can be explained by qualitatively different distributions of the particle density for the different confinement potentials.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 38
DOI: 10.1103/PhysRevE.85.031147
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“Tunable diffusion of magnetic particles in a quasi-one-dimensional channel”. Lucena D, Ferreira WP, Munarin FF, Farias GA, Peeters FM, Physical review : E : statistical, nonlinear, and soft matter physics 87, 012307 (2013). http://doi.org/10.1103/PhysRevE.87.012307
Abstract: The diffusion of a system of ferromagnetic dipoles confined in a quasi-one-dimensional parabolic trap is studied using Brownian dynamics simulations. We show that the dynamics of the system is tunable by an in-plane external homogeneous magnetic field. For a strong applied magnetic field, we find that the mobility of the system, the exponent of diffusion, and the crossover time among different diffusion regimes can be tuned by the orientation of the magnetic field. For weak magnetic fields, the exponent of diffusion in the subdiffusive regime is independent of the orientation of the external field. DOI: 10.1103/PhysRevE.87.012307
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 11
DOI: 10.1103/PhysRevE.87.012307
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“Self-assembly of Janus particles into helices with tunable pitch”. Sobrino Fernandez M, Misko VR, Peeters FM, Physical review : E : statistical, nonlinear, and soft matter physics 92, 042309 (2015). http://doi.org/10.1103/PhysRevE.92.042309
Abstract: Janus particles present an important class of building blocks for directional assembly. These are compartmentalized colloids with two different hemispheres. In this work we consider a three-dimensional model of Janus spheres that contain one hydrophobic and one charged hemisphere. Using molecular dynamics simulations, we study the morphology of these particles when confined in a channel-like environment. The interplay between the attractive and repulsive forces on each particle gives rise to a rich phase space where the relative orientation of each particle plays a dominant role in the formation of large-scale clusters. The interest in this system is primarily due to the fact that it could give a better understanding of the mechanisms of the formation of polar membranes. A variety of ordered membranelike morphologies is found consisting of single and multiple connected chain configurations. The helicity of these chains can be chosen by simply changing the salt concentration of the solution. Special attention is given to the formation of Bernal spirals. These helices are composed of regular tetrahedra and are known to exhibit nontrivial translational and rotational symmetry.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 18
DOI: 10.1103/PhysRevE.92.042309
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“Graphene ripples as a realization of a two-dimensional Ising model : a scanning tunneling microscope study”. Schoelz JK, Xu P, Meunier V, Kumar P, Neek-Amal M, Thibado PM, Peeters FM, Physical review: B: condensed matter and materials physics 91, 045413 (2015). http://doi.org/10.1103/PhysRevB.91.045413
Abstract: Ripples in pristine freestanding graphene naturally orient themselves in an array that is alternately curved-up and curved-down; maintaining an average height of zero. Using scanning tunneling microscopy (STM) to apply a local force, the graphene sheet will reversibly rise and fall in height until the height reaches 60%-70% of its maximum at which point a sudden, permanent jump occurs. We successfully model the ripples as a spin-half Ising magnetic system, where the height of the graphene plays the role of the spin. The permanent jump in height, controlled by the tunneling current, is found to be equivalent to an antiferromagnetic-to-ferromagnetic phase transition. The thermal load underneath the STM tip alters the local tension and is identified as the responsible mechanism for the phase transition. Four universal critical exponents are measured from our STM data, and the model provides insight into the statistical role of graphene's unusual negative thermal expansion coefficient.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 21
DOI: 10.1103/PhysRevB.91.045413
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“Mechanical resonance of the austenite/martensite interface and the pinning of the martensitic microstructures by dislocations in Cu74.08Al23.13Be2.79”. Salje EKH, Zhang H, Idrissi H, Schryvers D, Carpenter MA, Moya X, Planes A, Physical review: B: condensed matter and materials physics 80, 134114 (2009). http://doi.org/10.1103/PhysRevB.80.134114
Abstract: A single crystal of Cu74.08Al23.13Be2.79 undergoes a martensitic phase transition at 246 and 232 K under heating and cooling, respectively. The phase fronts between the austenite and martensite regions of the sample are weakly mobile with a power-law resonance under external stress fields. Surprisingly, the martensite phase is elastically much harder than the austenite phase showing that interfaces between various crystallographic variants are strongly pinned and cannot be moved by external stress while the phase boundary between the austenite and martensite regions in the sample remains mobile. This unusual behavior was studied by dynamical mechanical analysis (DMA) and resonant ultrasound spectroscopy. The remnant strain, storage modulus, and internal friction were recorded simultaneously for different applied forces in DMA. With increasing forces, the remnant strain increases monotonously while the internal friction peak height shows a minimum at 300 mN. Transmission electron microscopy shows that the pinning is generated by dislocations which are inherited from the austenite phase.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 38
DOI: 10.1103/PhysRevB.80.134114
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“Onset, evolution, and magnetic braking of vortex lattice instabilities in nanostructured superconducting films”. Adami O-A, Jelić, ŽL, Xue C, Abdel-Hafiez M, Hackens B, Moshchalkov VV, Milošević, MV, Van de Vondel J, Silhanek AV, Physical review: B: condensed matter and materials physics 92, 134506 (2015). http://doi.org/10.1103/PhysRevB.92.134506
Abstract: In 1976, Larkin and Ovchinnikov [Zh. Eksp. Teor. Fiz. 68, 1915 (1975) [Sov. Phys.–JETP 41, 960 (1976)]] predicted that vortex matter in superconductors driven by an electrical current can undergo an abrupt dynamic transition from a flux-flow regime to a more dissipative state at sufficiently high vortex velocities. Typically, this transition manifests itself as a large voltage jump at a particular current density, so-called instability current density J∗, which is smaller than the depairing current. By tuning the effective pinning strength in Al films, using an artificial periodic pinning array of triangular holes, we show that a unique and well-defined instability current density exists if the pinning is strong, whereas a series of multiple voltage transitions appear in the relatively weaker pinning regime. This behavior is consistent with time-dependent Ginzburg-Landau simulations, where the multiple-step transition can be unambiguously attributed to the progressive development of vortex chains and subsequently phase-slip lines. In addition, we explore experimentally the magnetic braking effects, caused by a thick Cu layer deposited on top of the superconductor, on the instabilities and the vortex ratchet effect.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 21
DOI: 10.1103/PhysRevB.92.134506
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“Orbital angular momentum in electron diffraction and its use to determine chiral crystal symmetries”. Juchtmans R, Verbeeck J, Physical review: B: condensed matter and materials physics 92, 134108 (2015). http://doi.org/10.1103/PhysRevB.92.134108
Abstract: In this work we present an alternative way to look at electron diffraction in a transmission electron microscope.
Instead of writing the scattering amplitude in Fourier space as a set of plane waves,we use the cylindrical Fourier transform to describe the scattering amplitude in a basis of orbital angular momentum (OAM) eigenstates. We show how working in this framework can be very convenient when investigating, e.g., rotation and screw-axis symmetries. For the latter we find selection rules on the OAM coefficients that unambiguously reveal the handedness of the screw axis. Detecting the OAM coefficients of the scattering amplitude thus offers the possibility to detect the handedness of crystals without the need for dynamical simulations, the thickness of the sample, nor the exact crystal structure. We propose an experimental setup to measure the OAM components where an image of the crystal is taken after inserting a spiral phase plate in the diffraction plane and perform multislice simulations on α quartz to demonstrate how the method indeed reveals the chirality. The experimental feasibility of the technique is discussed together with its main advantages with respect to chirality determination of screw axes. The method shows how the use of a spiral phase plate can be extended from a simple phase imaging technique to a tool to measure the local OAM decomposition of an electron wave, widening the field of interest well beyond chiral space group determination.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 16
DOI: 10.1103/PhysRevB.92.134108
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“Using self-driven microswimmers for particle separation”. Yang W, Misko VR, Nelissen K, Kong M, Peeters FM, Soft matter 8, 5175 (2012). http://doi.org/10.1039/c2sm07382j
Abstract: Microscopic self-propelled swimmers capable of autonomous navigation through complex environments provide appealing opportunities for localization, pick-up and delivery of micro and nanoscopic objects. Inspired by motile cells and bacteria, man-made microswimmers have been fabricated, and their motion in patterned surroundings has been experimentally studied. We propose to use self-driven artificial microswimmers for the separation of binary mixtures of colloids. We revealed different regimes of separation, including one with a velocity inversion. Our findings could be of use for various biological and medical applications.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.889
Times cited: 45
DOI: 10.1039/c2sm07382j
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“A combined 3D and 2D light scattering study on aqueous colloidal model systems with tunable interactions”. Liu Y, Claes N, Trepka B, Bals S, Lang PR, Soft matter 12, 8485 (2016). http://doi.org/10.1039/c6sm01376g
Abstract: In this article we report on the synthesis and characterization of a system of colloidal spheres suspended in an aqueous solvent which can be refractive index-matched, thus allowing for investigations of the particle near-wall dynamics by evanescent wave dynamic light scattering at concentrations up to the isotropic to ordered transition and beyond. The particles are synthesized by copolymerization of a fluorinated acrylic ester monomer with a polyethylene-glycol (PEG) oligomer by surfactant free emulsion polymerization. Static and dynamic light scattering experiments in combination with cryo transmission electron microscopy reveal that the particles have a core shell structure with a significant enrichment of the PEG chains on the particles surface. In index-matching DMSO/water suspensions the particles arrange in an ordered phase at volume fraction above 7%, if no additional electrolyte is present. The near-wall dynamics at low volume fraction are quantitatively described by the combination of electrostatic repulsion and hydrodynamic interaction between the particles and the wall. At volume fractions close to the isotropic to ordered transition, the near-wall dynamics are more complex and qualitatively reminiscent of the behaviour which was observed in hard sphere suspensions at high concentrations.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.889
Times cited: 2
DOI: 10.1039/c6sm01376g
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