“Melting of anisotropically confined Coulomb balls”. Apolinario SWS, Peeters FM, Physical review : B : condensed matter and materials physics 78, 024202 (2008). http://doi.org/10.1103/PhysRevB.78.024202
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 10
DOI: 10.1103/PhysRevB.78.024202
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“Crystal structure, phase transition, and magnetic ordering in perovskitelike Pb2-xBaxFe2O5 solid solutions”. Nikolaev IV, d' Hondt H, Abakumov AM, Hadermann J, Balagurov AM, Bobrikov IA, Sheptyakov DV, Pomjakushin VY, Pokholok KV, Filimonov DS, Van Tendeloo G, Antipov EV, Physical review : B : condensed matter and materials physics 78, 024426 (2008). http://doi.org/10.1103/PhysRevB.78.024426
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 29
DOI: 10.1103/PhysRevB.78.024426
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“Magnetic-field induced quantum-size cascades in superconducting nanowires”. Shanenko AA, Croitoru MD, Peeters FM, Physical review : B : condensed matter and materials physics 78, 024505 (2008). http://doi.org/10.1103/PhysRevB.78.024505
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 42
DOI: 10.1103/PhysRevB.78.024505
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“Pillars as antipinning centers in superconducting films”. Berdiyorov GR, Misko VR, Milošević, MV, Escoffier W, Grigorieva IV, Peeters FM, Physical review : B : condensed matter and materials physics 77, 024526 (2008). http://doi.org/10.1103/PhysRevB.77.024526
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 35
DOI: 10.1103/PhysRevB.77.024526
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“Effect of transport of growing nanoparticles on capacitively coupled rf discharge dynamics”. Schweigert IV, Alexandrov AL, Ariskin DA, Peeters FM, Stefanović, I, Kovačević, E, Berndt J, Winter J, Physical review : E : statistical physics, plasmas, fluids, and related interdisciplinary topics 78, 026410 (2008). http://doi.org/10.1103/PhysRevE.78.026410
Abstract: We present experimental and numerical studies of the properties of a capacitively coupled 13.56 MHz discharge in a mixture of Ar and C2H2 with growing nanosize particles. It is found that at the initial stage of the growth, nanoparticles are accumulated near the sheath-plasma boundaries, where the ionization by electrons is maximal. The nanoparticles suppress the ionization due to the absorbing fast electrons and stimulate a quick change of the plasma parameters followed by a transition between different modes of discharge operation. At that moment the peaked distribution of the dust particles transforms into a flat one.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 36
DOI: 10.1103/PhysRevE.78.026410
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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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“Hysteresis and reentrant melting of a self-organized system of classical particles confined in a parabolic trap”. Munarin FF, Nelissen K, Ferreira WP, Farias GA, Peeters FM, Physical review : E : statistical physics, plasmas, fluids, and related interdisciplinary topics 77, 031608 (2008). http://doi.org/10.1103/PhysRevE.77.031608
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 11
DOI: 10.1103/PhysRevE.77.031608
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“On the reaction behaviour of hydrocarbon species at diamond (1 0 0) and (1 1 1) surfaces: a molecular dynamics investigation”. Eckert M, Neyts E, Bogaerts A, Journal of physics: D: applied physics 41, 032006 (2008). http://doi.org/10.1088/0022-3727/41/3/032006
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.588
Times cited: 17
DOI: 10.1088/0022-3727/41/3/032006
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“The effect of temperature on the structural, electronic and optical properties of sp3-rich amorphous carbon”. Titantah JT, Lamoen D, Journal of physics : condensed matter 20, 035216 (2008). http://doi.org/10.1088/0953-8984/20/03/035216
Abstract: The effect of temperature on the structural, electronic and optical properties of dense tetrahedral amorphous carbon made of similar to 80% sp(3)-bonded atoms is investigated using a combination of the classical Monte Carlo technique and density functional theory. A structural transformation accompanied by a slight decrease of the sp(3) fraction is evidenced above a temperature of about 600 degrees C. A structural analysis in combination with energy-loss near-edge structure calculations shows that beyond this temperature, the sp(2)-bonded C sites arrange themselves so as to enhance the conjugation of the p electrons. The Tauc optical band gap deduced from the calculated dielectric function shows major changes beyond this temperature in accordance with experimental results. Energy-loss near-edge structure and band gap calculations additionally reveal a massive destabilization of the of sp(3) bonding phase in favour of sp(2) bonding at a temperature of about 1300 degrees C which agrees very well with the reported value of 1100 degrees C.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.649
Times cited: 11
DOI: 10.1088/0953-8984/20/03/035216
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“Multiple rings in a 3D anisotropic Wigner crystal: structural and dynamical properties”. Apolinario SWS, Partoens B, Peeters FM, Physical review : B : condensed matter and materials physics 77, 035321 (2008). http://doi.org/10.1103/PhysRevB.77.035321
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 17
DOI: 10.1103/PhysRevB.77.035321
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“Direct observation of nanometer-scale pinning sites in (Nd0.33Eu0.20Gd0.47)Ba2Cu3O7-\delta single crystals”. Das P, Koblischka MR, Turner S, Van Tendeloo G, Wolf T, Jirsa M, Hartmann U, Europhysics letters 83, 37005 (2008). http://doi.org/10.1209/0295-5075/83/37005
Abstract: We report on the observation of self-organized stripe-like structures on the as-grown surface and in the bulk of (Nd,Eu,Gd)Ba2Cu3Oy single crystals. The periodicity of the stripes on the surface lies between 500800 nm. These are possibly the growth steps of the crystal. Transmission electron microscopy investigations revealed stripes of periodicity in the range of 2040 nm in the bulk. From electron back scattered diffraction investigations, no crystallographic misorientation due to the nanostripes has been found. Scanning tunneling spectroscopic experiments revealed nonsuperconducting regions, running along twin directions, which presumably constitute strong pinning sites.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.957
Times cited: 5
DOI: 10.1209/0295-5075/83/37005
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“The dominant role of impurities in the composition of high pressure noble gas plasmas”. Martens T, Bogaerts A, Brok WJM, van Dijk J, Applied physics letters 92, 041504 (2008). http://doi.org/10.1063/1.2839613
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.411
Times cited: 115
DOI: 10.1063/1.2839613
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“Functionalization of MWCNTs with atomic nitrogen : electronic structure”. Ruelle B, Felten A, Ghijsen J, Drube W, Johnson RL, Liang D, Erni R, Van Tendeloo G, Dubois P, Hecq M, Bittencourt C;, Journal of physics: D: applied physics 41, 045202 (2008). http://doi.org/10.1088/0022-3727/41/4/045202
Abstract: The changes induced by exposing multi-walled carbon nanotubes (CNTs) to atomic nitrogen were analysed by high-resolution transmission electron microscopy (HRTEM), x-ray and ultraviolet photoelectron spectroscopy. It was found that the atomic nitrogen generated by a microwave plasma effectively grafts chemical groups onto the CNT surface altering the density of valence electronic states. HRTEM showed that the exposure to atomic nitrogen does not significantly damage the CNT surface.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.588
Times cited: 16
DOI: 10.1088/0022-3727/41/4/045202
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“Magnetic field dependence of the many-electron statis in a magnetic quantum dot: the ferromagnetic-antiferromagnetic transition”. Nguyen NTT, Peeters FM, Physical review : B : condensed matter and materials physics 78, 045321 (2008). http://doi.org/10.1103/PhysRevB.78.045321
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 41
DOI: 10.1103/PhysRevB.78.045321
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“Electron-vortex separation in quantum dots”. Anisimovas E, Tavernier MB, Peeters FM, Physical review : B : condensed matter and materials physics 77, 045327 (2008). http://doi.org/10.1103/PhysRevB.77.045327
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 3
DOI: 10.1103/PhysRevB.77.045327
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“Electronic states above a helium film suspended on a ring-shaped substrate”. Ramos ACA, Chaves A, Farias GA, Peeters FM, Physical review : B : condensed matter and materials physics 77, 045415 (2008). http://doi.org/10.1103/PhysRevB.77.045415
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 4
DOI: 10.1103/PhysRevB.77.045415
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“Topologically trapped vortex molecules in Bose-Einstein condensates”. Geurts R, Milošević, MV, Peeters FM, Physical review : A : atomic, molecular and optical physics 78, 053610 (2008). http://doi.org/10.1103/PhysRevA.78.053610
Abstract: In a numerical experiment based on Gross-Pitaevskii formalism, we demonstrate unique topological quantum coherence in optically trapped Bose-Einstein condensates (BECs). Exploring the fact that vortices in a rotating BEC can be pinned by a geometric arrangement of laser beams, we show the parameter range in which vortex-antivortex molecules or multiquantum vortices are formed as a consequence of the optically imposed symmetry. Being low-energy states, we discuss the conditions for spontaneous nucleation of these unique molecules and their direct experimental observation, and provoke the potential use of the phase print of an antivortex or a multiquantum vortex when realized in unconventional circumstances.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.925
Times cited: 12
DOI: 10.1103/PhysRevA.78.053610
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“Superconducting nanofilms: Andreev-type states induced by quantum confinement”. Shanenko AA, Croitoru MD, Peeters FM, Physical review : B : solid state 78, 054505 (2008). http://doi.org/10.1103/PhysRevB.78.054505
Abstract: Quantum confinement of the transverse electron motion is the major effect governing the superconducting properties of high-quality metallic nanofilms, leading to a nonuniform transverse distribution of the superconducting condensate. In this case the order parameter can exhibit significant local enhancements due to these quantum-size effects and, consequently, quasiparticles have lower energies when they avoid the local enhancements of the pair condensate. Such excitations can be considered as new Andreev-type quasiparticles but now induced by quantum confinement. By numerically solving the Bogoliubovde Gennes equations and using Anderson's approximate solution to these equations, we: (a) formulate a criterion for such new Andreev-type states (NATS) and (b) study their effect on the superconducting characteristics in metallic nanofilms. We also argue that nanofilms made of low-carrier-density materials, e.g., of superconducting semiconductors, can be a more optimal choice for the observations of NATS and other quantum-size superconducting effects.
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 14
DOI: 10.1103/PhysRevB.78.054505
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“Vortices in a mesoscopic cone: a superconducting tip in the presence of an applied field”. Chen Y, Doria MM, Peeters FM, Physical review : B : condensed matter and materials physics 77, 054511 (2008). http://doi.org/10.1103/PhysRevB.77.054511
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 19
DOI: 10.1103/PhysRevB.77.054511
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“The martensitic phase transition in Ni-Al: experimental observation of excess entropy and heterogeneous spontaneous strain”. Zhang H, Salje EKH, Schryvers D, Bartova B, Journal of physics : condensed matter 20, 055220 (2008). http://doi.org/10.1088/0953-8984/20/5/055220
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.649
Times cited: 7
DOI: 10.1088/0953-8984/20/5/055220
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“Long-range Coulomb repulsion effect on a charged vortex in high-temperature superconductors with competing d-wave and antiferromagnetic orders”. Zhao H-W, Zha G-Q, Zhou S-P, Peeters FM, Physical review : B : solid state 78, 064505 (2008). http://doi.org/10.1103/PhysRevB.78.064505
Abstract: Vortex charges in high-temperature superconductor (HTS) are studied by solving the Bogoliubovde Gennes equations based on a model Hamiltonian with antiferromagnetic (AF) and d-wave orders in the presence of the long-range Coulomb repulsion. For a sufficient strength of the AF order, the negative vortex charge is found. A sign change between negative and positive may occur by tuning the long-range Coulomb repulsion strength or the doping parameter. Recent NMR experiments are hopefully understood. We show that the charged vortex can induce a spin-orbit coupling that is important for superconductors with a short coherence length and a large value of the energy gap over the Fermi-level ratio. Fractional flux quanta are possible for HTS.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 12
DOI: 10.1103/PhysRevB.78.064505
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“Simulation of an Ar/Cl2 inductively coupled plasma: study of the effect of bias, power and pressure and comparison with experiments”. Tinck S, Boullart W, Bogaerts A, Journal of physics: D: applied physics 41, 065207 (2008). http://doi.org/10.1088/0022-3727/41/6/065207
Abstract: A hybrid model, called the hybrid plasma equipment model, was used to study Ar/Cl(2) inductively coupled plasmas used for the etching of Si. The effects of substrate bias, source power and gas pressure on the plasma characteristics and on the fluxes and energies of plasma species bombarding the substrate were observed. A comparison with experimentally measured etch rates was made to investigate how the etch process is influenced and which plasma species mainly account for the etch process. First, the general plasma characteristics are investigated at the following operating conditions: 10% Ar 90% Cl(2) gas mixture, 5mTorr total gas pressure, 100 sccm gas flow rate, 250W source power, -200V dc bias at the substrate electrode and an operating frequency of 13.56MHz applied to the coil and to the substrate electrode. Subsequently, the pressure is varied from 5 to 80mTorr, the substrate bias from -100 to -300V and the source power from 250 to 1000W. Increasing the total gas pressure results in a decrease of the etch rate and a less anisotropic flux to the substrate due to more collisions of the ions in the sheath. Increasing the substrate bias has an effect on the energy of the ions bombarding the substrate and to a lesser extent on the magnitude of the ion flux. When source power is increased, it was found that, not the energy, but the magnitude of the ion flux is increased. The etch rate was more influenced by a variation of the substrate bias than by a variation of the source power, at these operating conditions. These results suggest that the etch process is mainly affected by the energy of the ions bombarding the substrate and the magnitude of the ion flux, and to a lesser extent by the magnitude of the radical flux.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.588
Times cited: 31
DOI: 10.1088/0022-3727/41/6/065207
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“Electrostatic modes in multi-ion and pair-ion collisional plasmas”. Vranjes J, Petrovic D, Pandey BP, Poedts S, Physics of plasmas 15, 072104 (2008). http://doi.org/10.1063/1.2949696
Abstract: The physics of plasmas containing positive and negative ions is discussed with special attention to the recently produced pair-ion plasma containing ions of equal mass and opposite charge. The effects of the density gradient in the direction perpendicular to the ambient magnetic field vector are discussed. The possible presence of electrons is discussed in the context of plasma modes propagating at an angle with respect to the magnetic field vector. It is shown that the electron plasma mode may become a backward mode in the presence of a density gradient, and this behavior may be controlled either by the electron number density or the mode number in the perpendicular direction. In plasmas with hot electrons an instability may develop, driven by the combination of electron collisions and the density gradient, and in the regime of a sound ions' response. In the case of a pure pair-ion plasma, for lower frequencies and for parameters close to those used in the recent experiments, the perturbed ions may feel the effects of the magnetic field. In this case the plasma mode also becomes backward, resembling features of an experimentally observed but yet unexplained backward mode. (C) 2008 American Institute of Physics.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.115
Times cited: 54
DOI: 10.1063/1.2949696
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“Optical properties of free-standing GaAs semiconductor nanowires and their dependence on the growth direction”. Redli<<0144>>ski P, Peeters FM, Physical review : B : condensed matter and materials physics 77, 075329 (2008). http://doi.org/10.1103/PhysRevB.77.075329
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 21
DOI: 10.1103/PhysRevB.77.075329
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“Effect of a metallic gate on the energy levels of a shallow donor”. Slachmuylders AF, Partoens B, Peeters FM, Magnus W, Applied physics letters 92, 083104 (2008). http://doi.org/10.1063/1.2888742
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.411
Times cited: 14
DOI: 10.1063/1.2888742
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“Theory of the evolution of phonon spectra and elastic constants from graphene to graphite”. Michel KH, Verberck B, Physical review : B : solid state 78, 085424 (2008). http://doi.org/10.1103/PhysRevB.78.085424
Abstract: We present a unified theory of the phonon dispersions and elastic properties of graphene, graphite, and graphene multilayer systems. Starting from a fifth-nearest-neighbor force-constant model derived from full in-plane phonon dispersions of graphite [Mohr et al., Phys. Rev. B 76, 035439 (2007)], we use Born's long-wave method to calculate the tension and bending coefficients of graphene. Extending the model by interplanar interactions, we study the phonon dispersions and the elastic constants of graphite, and the phonon spectra of graphene multilayers. We find that the inner displacement terms due to sublattice shifts between inequivalent C atoms are quantitatively important in determining the elastomechanical properties of graphene and of graphite. The overall agreement between theory and experiment is very satisfactory. We investigate the evolution from graphene to graphite by studying the increase in the rigid plane optical mode as a function of the number of layers N. At N=10 the graphite value B2g1127 cm−1 is attained within a few percent.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 72
DOI: 10.1103/PhysRevB.78.085424
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“A non-Maxwellian kinetic approach for charging of dust particles in discharge plasmas”. Alexandrov AL, Schweigert IV, Peeters FM, New journal of physics 10, 093025 (2008). http://doi.org/10.1088/1367-2630/10/9/093025
Abstract: Nanoparticle charging in a capacitively coupled radio frequency discharge in argon is studied using a particle in cell Monte Carlo collisions method. The plasma parameters and dust potential were calculated self-consistently for different unmovable dust profiles. A new method for definition of the dust floating potential is proposed, based on the information about electron and ion energy distribution functions, obtained during the kinetic simulations. This approach provides an accurate balance of the electron and ion currents on the dust particle surface and allows us to precisely calculate the dust floating potential. A comparison of the obtained floating potentials with the results of the traditional orbital motion limit (OML) theory shows that in the presence of the ion resonant charge exchange collisions, even when the OML approximation is valid, its results are correct only in the region of a weak electric field, where the ion drift velocity is much smaller than the thermal one. With increasing ion drift velocity, the absolute value of the calculated dust potential becomes significantly smaller than the theory predicts. This is explained by a non-Maxwellian shape of the ion energy distribution function for the case of fast ion drift.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.786
Times cited: 19
DOI: 10.1088/1367-2630/10/9/093025
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“Calculation of gas heating in a dc sputter magnetron”. Kolev I, Bogaerts A, Journal of applied physics 104, 093301 (2008). http://doi.org/10.1063/1.2970166
Abstract: The effect of gas heating in laboratory sputter magnetrons is investigated by means of numerical modeling. The model is two-dimensional in the coordinate space and three-dimensional in the velocity space based on the particle-in-cellMonte Carlo collisions technique. It is expanded in a way that allows the inclusion of the neutral plasma particles (fast gas atoms and sputtered atoms), which makes it possible to calculate the gas temperature and its influence on the discharge behavior in a completely self-consistent way. The results of the model are compared to experimental measurements and to other existing simulation results. The results show that gas heating is pressure dependent (rising with the increase in the gas pressure) and should be taken into consideration at pressures above 10 mTorr.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.068
Times cited: 19
DOI: 10.1063/1.2970166
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“Giant proximity effect in a phase-fluctuating superconductor”. Marchand D, Covaci L, Berciu M, Franz M, Physical Review Letters 101, 097004 (2008). http://doi.org/10.1103/PhysRevLett.101.097004
Abstract: When a tunneling barrier between two superconductors is formed by a normal material that would be a superconductor in the absence of phase fluctuations, the resulting Josephson effect can undergo an enormous enhancement. We establish this novel proximity effect by a general argument as well as a numerical simulation and argue that it may underlie recent experimental observations of the giant proximity effect between two cuprate superconductors separated by a barrier made of the same material rendered normal by severe underdoping.
Keywords: A1 Journal article
Impact Factor: 8.462
Times cited: 17
DOI: 10.1103/PhysRevLett.101.097004
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“Vortex states in mesoscopic superconducting squares: formation of vortex shells”. Zhao HJ, Misko VR, Peeters FM, Oboznov V, Dubonos SV, Grigorieva IV, Physical review : B : condensed matter and materials physics 78, 104517 (2008). http://doi.org/10.1103/PhysRevB.78.104517
Abstract: We analyze theoretically and experimentally vortex configurations in mesoscopic superconducting squares. Our theoretical approach is based on the analytical solution of the London equation using Green's-function method. The potential-energy landscape found for each vortex configuration is then used in Langevin-type molecular-dynamics simulations to obtain stable vortex configurations. Metastable states and transitions between them and the ground state are analyzed. We present our results of the first direct visualization of vortex patterns in micrometer-sized Nb squares, using the Bitter decoration technique. We show that the filling rules for vortices in squares with increasing applied magnetic field can be formulated, although in a different manner than in disks, in terms of formation of vortex “shells”.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 39
DOI: 10.1103/PhysRevB.78.104517
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