“Landau levels in graphene bilayer quantum dots”. Pereira JM, Peeters FM, Vasilopoulos P, Costa Filho RN, Farias GA, Physical review : B : solid state 79, 195403 (2009). http://doi.org/10.1103/PhysRevB.79.195403
Abstract: We investigate localized electron and hole states in parabolic quantum dots of biased graphene bilayers in the presence of a perpendicular magnetic field. These quantum dots can be created by means of nanostructured gates or by position-dependent doping, which can create a gap in the otherwise gapless dispersion of a graphene bilayer. Numerical results show the energy levels of confined electrons and holes as a function of the dot parameters and the magnetic field. Remarkable crossings of energy levels are found.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 29
DOI: 10.1103/PhysRevB.79.195403
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“Local current injection into mesoscopic superconductors for the manipulation of quantum states”. Milošević, MV, Kanda A, Hatsumi S, Peeters FM, Ootuka Y, Physical review letters 103, 217003 (2009). http://doi.org/10.1103/PhysRevLett.103.217003
Abstract: We perform strategic current injection in a small mesoscopic superconductor and control the (non)equilibrium quantum states in an applied homogeneous magnetic field. In doing so, we realize a current-driven splitting of multiquanta vortices, current-induced transitions between states with different angular momenta, and current-controlled switching between otherwise degenerate quantum states. These fundamental phenomena form the basis for the electronic and logic applications discussed, and are confirmed in both theoretical simulations and multiple-small-tunnel-junction transport measurements.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 8.462
Times cited: 48
DOI: 10.1103/PhysRevLett.103.217003
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“Magnetic-field asymmetry of electron wave packet transmission in bent channels capacitively coupled to a metal gate”. Kalina R, Szafran B, Bednarek S, Peeters FM, Physical review letters 102, 066807 (2009). http://doi.org/10.1103/PhysRevLett.102.066807
Abstract: We study the electron wave packet moving through a bent channel. We demonstrate that the packet transmission probability becomes an asymmetric function of the magnetic field when the electron packet is capacitively coupled to a metal plate. The coupling occurs through a nonlinear potential which translates a different kinetics of the transport for opposite magnetic-field orientations into a different potential felt by the scattered electron.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 8.462
Times cited: 14
DOI: 10.1103/PhysRevLett.102.066807
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“Magnetic flux periodicity in mesoscopic d-wave symmetric and asymmetric superconducting loops”. Zha G-Q, Milošević, MV, Zhou S-P, Peeters FM, Physical review : B : solid state 80, 144501 (2009). http://doi.org/10.1103/PhysRevB.80.144501
Abstract: The magnetic flux dependence of energy and supercurrent in mesoscopic d-wave symmetric and asymmetric superconducting loops is investigated by numerically solving the Bogoliubov-de Gennes equations self-consistently. For square loops, we find an hc/e-flux periodicity in energy and supercurrent and demonstrate that the flux periodicity is sensitive to the hole size and the superconducting pairing strength as well as temperature. The hc/2e-periodic behavior can be restored almost entirely when we displace the central hole sufficiently out of the center of the sample. In rectangular loops, the discrete current-carrying low-energy spectrum can exist for an odd winding number of the order parameter.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 13
DOI: 10.1103/PhysRevB.80.144501
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“Magnetic Kronig-Penney model for Dirac electrons in single-layer graphene”. Masir MR, Vasilopoulos P, Peeters FM, New journal of physics 11, 095009 (2009). http://doi.org/10.1088/1367-2630/11/9/095009
Abstract: he properties of Dirac electrons in a magnetic superlattice (SL) on graphene consisting of very high and thin (δ-function) barriers are investigated. We obtain the energy spectrum analytically and study the transmission through a finite number of barriers. The results are contrasted with those for electrons described by the Schrödinger equation. In addition, a collimation of an incident beam of electrons is obtained along the direction perpendicular to that of the SL. We also highlight an analogy with optical media in which the refractive index varies in space.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.786
Times cited: 89
DOI: 10.1088/1367-2630/11/9/095009
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“Magneto-ballistic transport through micro-structured junctions on a curved two-dimensional electron gas”. Papp G, Peeters FM, Solid state communications 149, 778 (2009). http://doi.org/10.1016/j.ssc.2009.02.033
Abstract: We investigate theoretically the ballistic transport in a two-dimensional electron gas, which is rolled up as a tube and is micro-structured into a Hall bar. A uniform magnetic field applied to such a curved surface results in a non-uniform perpendicular magnetic field. The bend resistances become asymmetric with respect to the orientation of the magnetic field due to the varying magnetic field along the junction. The resistance asymmetry is strongly affected by corrugation due to the varying mobility along different crystallographic directions. We compare our results with a recent transport measurement.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.554
Times cited: 1
DOI: 10.1016/j.ssc.2009.02.033
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“Many-body effects in the cyclotron resonance of a magnetic dot”. Nguten NTT, Peeters FM, Physical review : B : solid state 80, 115335 (2009). http://doi.org/10.1103/PhysRevB.80.115335
Abstract: Intraband cyclotron resonance (CR) transitions of a two-electron quantum dot containing a single magnetic ion is investigated for different Coulomb interaction strengths and different positions of the magnetic ion. In contrast to the usual parabolic quantum dots where CR is independent of the number of electrons, we found here that due to the presence of the magnetic ion Kohn's theorem no longer holds and CR is different for systems with different number of electrons and different effective electron-electron Coulomb interaction strength. Many-body effects result in shifts in the transition energies and change the number of CR lines. The position of the magnetic ion inside the quantum dot affects the structure of the CR spectrum by changing the position and the number of crossings and anticrossings in the transition energies and oscillator strengths.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 6
DOI: 10.1103/PhysRevB.80.115335
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“Modeling of chemical processes in the low pressure capacitive radio frequency discharges in a mixture of Ar/C2H2”. Ariskin DA, Schweigert IV, Alexandrov AL, Bogaerts A, Peeters FM, Journal of applied physics 105, 063305 (2009). http://doi.org/10.1063/1.3095760
Abstract: We study the properties of a capacitive 13.56 MHz discharge with a mixture of Ar/C<sub>2</sub>H<sub>2</sub> taking into account the plasmochemistry and growth of heavy hydrocarbons. A hybrid model was developed to combine the kinetic description for electron motion and the fluid approach for negative and positive ion transports and plasmochemical processes. A significant change in plasma parameters related to injection of 5.8% portion of acetylene in argon was observed and analyzed. We found that the electronegativity of the mixture is about 30%. The densities of negatively and positively charged heavy hydrocarbons are sufficiently large to be precursors for the formation of nanoparticles in the discharge volume.
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.068
Times cited: 21
DOI: 10.1063/1.3095760
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“Neutral shallow donors near a metallic interface”. Slachmuylders AF, Partoens B, Magnus W, Peeters FM, Microelectronics journal 40, 753 (2009). http://doi.org/10.1016/j.mejo.2008.11.010
Abstract: The effect of a metallic gate on the bound states of a shallow donor located near the gate is studied. We calculate the energy spectrum as a function of the distance between the metallic gate and the donor and find an anti-crossing behavior in the energy levels for certain distances. We show how a transverse electric field can tune the average position of the electron with respect to the metallic gate and the impurity.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.163
Times cited: 1
DOI: 10.1016/j.mejo.2008.11.010
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“Optical conductance and transmission in bilayer graphene”. Dhong HM, Zhang J, Peeters FM, Xu W, Journal of applied physics 106, 043103 (2009). http://doi.org/10.1063/1.3200959
Abstract: We present a theoretical study of the optoelectronic properties of bilayer graphene. The optical conductance and transmission coefficient are calculated using the energy-balance equation derived from a Boltzmann equation for an air/graphene/dielectric-wafer system. For short wavelengths (<0.2 µm), we obtain the universal optical conductance =e2/(2). Interestingly, there exists an optical absorption window in the wavelength range 10100 µm, which is induced by different transition energies required for inter- and intra-band optical absorptions in the presence of the MossBurstein effect. As a result, the position and width of this absorption window depend sensitively on temperature, carrier density, and sample mobility of the system. These results are relevant for applications of recently developed graphene devices in advanced optoelectronics such as the infrared photodetectors.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.068
Times cited: 11
DOI: 10.1063/1.3200959
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“Phonon band structure of Si nanowires: a stability analysis”. Peelaers H, Partoens B, Peeters FM, Nano letters 9, 107 (2009). http://doi.org/10.1021/nl802613p
Abstract: We present full ab initio calculations of the phonon band structure of thin Si nanowires oriented along the [110] direction. Using these phonon dispersion relations, we investigate the structural stability of these wires. We found that all studied wires were stable also when doped with either B or P, if the unit cell was taken sufficiently large along the wire axis. The evolution of the phonon dispersion relations and of the sound velocities with respect to the wire diameters is discussed. Softening is observed for acoustic modes and hardening for optical phonon modes with increasing wire diameters.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 12.712
Times cited: 51
DOI: 10.1021/nl802613p
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“Phonon band structures of Si nanowires”. Peelaers H, Partoens B, Peeters FM, AIP conference proceedings 1199, 323 (2009). http://doi.org/10.1063/1.3295432
Abstract: We present full ab initio calculations of the phonon band structure of thin Si nanowires oriented along the [110] direction. Using these phonon dispersion relations we investigate the structural stability of these wires. We found that all studied wires were stable also when doped with either B or P, if the unit cell was taken sufficiently large along the wire axis. The evolution of the phonon dispersion relations and of the sound velocities with respect to the wire diameters is discussed. Softening is observed for acoustic modes and hardening for optical phonon modes with increasing wire diameters.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
DOI: 10.1063/1.3295432
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“Phonons in Ge nanowires”. Peelaers H, Partoens B, Peeters FM, Applied physics letters 95, 122110 (2009). http://doi.org/10.1063/1.3236526
Abstract: The phonon spectra of thin freestanding, hydrogen passivated, Ge nanowires are calculated by ab initio techniques. The effect of confinement on the phonon modes as caused by the small diameters of the wires is investigated. Confinement causes a hardening of the optical modes and a softening of the longitudinal acoustic modes. The stability of the nanowires, undoped or doped with B or P atoms, is investigated using the obtained phonon spectra. All considered wires were stable, except for highly doped, very thin nanowires.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.411
Times cited: 12
DOI: 10.1063/1.3236526
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“Quantum rings with time-dependent spin-orbit coupling: Spintronic Rabi oscillations and conductance properties”. Földi P, Benedict MG, Kalman O, Peeters FM, Physical review : B : solid state 80, 165303 (2009). http://doi.org/10.1103/PhysRevB.80.165303
Abstract: The strength of the (Rashba-type) spin-orbit coupling in mesoscopic semiconductor rings can be tuned with external gate voltages. Here we consider the case of a periodically changing spin-orbit interaction strength in time as induced by sinusoidal voltages. In a closed one dimensional quantum ring with weak spin-orbit coupling, Rabi oscillations are shown to appear. We find that the time evolution of initially localized wave packets exhibits a series of collapse and revival phenomena. Partial revivalsthat are typical in nonlinear systemsare shown to correspond to superpositions of states localized at different spatial positions along the ring. These spintronic Schrödinger-cat states appear periodically, and similarly to their counterparts in other physical systems, they are found to be sensitive to disturbances caused by the environment. The time-dependent spin transport problem, when leads are attached to the ring, is also solved. We show that the sideband currents induced by the oscillating spin-orbit interaction strength can become the dominant output channel, even in the presence of moderate thermal fluctuations and random scattering events.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 26
DOI: 10.1103/PhysRevB.80.165303
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“Quasibound states of Schrödinger and Dirac electrons in a magnetic quantum dot”. Masir MR, Matulis A, Peeters FM, Physical review : B : solid state 79, 155451 (2009). http://doi.org/10.1103/PhysRevB.79.155451
Abstract: The properties of a two-dimensional electron are investigated in the presence of a circular step magnetic-field profile. Both electrons with parabolic dispersion as well as Dirac electrons with linear dispersion are studied. We found that in such a magnetic quantum dot no electrons can be confined. Nevertheless close to the Landau levels quasibound states can exist with a rather long lifetime.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 55
DOI: 10.1103/PhysRevB.79.155451
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“Resonant tunneling through S- and U-shaped graphene nanoribbons”. Zhang ZZ, Wu ZH, Chang K, Peeters FM, Nanotechnology 20, 415203 (2009). http://doi.org/10.1088/0957-4484/20/41/415203
Abstract: We theoretically investigate resonant tunneling through S- and U-shaped nanostructured graphene nanoribbons. A rich structure of resonant tunneling peaks is found emanating from different quasi-bound states in the middle region. The tunneling current can be turned on and off by varying the Fermi energy. Tunability of resonant tunneling is realized by changing the width of the left and/or right leads and without the use of any external gates.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.44
Times cited: 32
DOI: 10.1088/0957-4484/20/41/415203
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“Second generation of vortex-antivortex states in mesoscopic superconductors: stabilization by artificial pinning”. Geurts R, Milošević, MV, Peeters FM, Physical review : B : solid state 79, 174508 (2009). http://doi.org/10.1103/PhysRevB.79.174508
Abstract: Antagonistic symmetries of superconducting polygons and their induced multivortex states in a homogeneous magnetic field may lead to the appearance of antivortices in the vicinity of the superconducting/normal-state boundary (where mesoscopic confinement is particularly strong). Resulting vortex-antivortex (V-Av) molecules match the sample symmetry but are extremely sensitive to defects and fluctuations and remain undetected experimentally. Here we show that V-Av states can reappear deep in the superconducting state due to an array of perforations in a polygonal setting, surrounding a central hole. Such states are no longer caused by the symmetry of the sample but rather by pinning itself, which prevents the vortex-antivortex annihilation. As a result, even micron size, clearly spaced V-Av molecules can be stabilized in large mesoscopic samples.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 17
DOI: 10.1103/PhysRevB.79.174508
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“Selective suppression of Dresselhaus or Rashba spin-orbit coupling effects by the Zeeman interaction in quantum dots”. Szafran B, Nowak MP, Bednarek S, Chwiej T, Peeters FM, Physical review : B : solid state 79, 235303 (2009). http://doi.org/10.1103/PhysRevB.79.235303
Abstract: We study single- and two-electron parabolic quantum dots in the presence of linear Dresselhaus and Rashba spin-orbit interactions. Contributions of both types of spin-orbit coupling are investigated in the context of the spin polarization of the system at high magnetic fields. We demonstrate that for negative Landé factors the effect of the Dresselhaus coupling is suppressed at high magnetic field, which for structures without inversion asymmetry leads to a completely spin-polarized system and a strict antisymmetry of the wave functions with respect to the interchange of spatial-electron coordinates. For negative Landé factor the Rashba coupling is preserved at high field and consequently the spin polarization of the systems as well as the spatial antisymmetry of the two-electron wave function remain approximate.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 13
DOI: 10.1103/PhysRevB.79.235303
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“Shallow donor states near a semiconductor-insulator-metal interface”. Hao YL, Djotyan AP, Avetisyan AA, Peeters FM, Physical review : B : solid state 80, 035329 (2009). http://doi.org/10.1103/PhysRevB.80.035329
Abstract: The lowest energy electronic states of a donor located near a semiconductor-insulator-metal interface are investigated within the effective mass approach. The effect of the finite thickness of the insulator between the semiconductor and the metallic gate on the energy levels is studied. The lowest energy states are obtained through a variational approach, which takes into account the influence of all image charges that arise due to the presence of the metallic and the dielectric interfaces. We compare our results with a numerical exact calculation using the finite element technique.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 22
DOI: 10.1103/PhysRevB.80.035329
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“Stability of spintronic devices based on quantum ring networks”. Földi P, Kálmán O, Peeters FM, Physical review : B : solid state 80, 125324 (2009). http://doi.org/10.1103/PhysRevB.80.125324
Abstract: Transport properties in mesoscopic networks are investigated, where the strength of the (Rashba-type) spin-orbit coupling is tuned with external gate voltages. We analyze in detail to what extent the ideal behavior and functionality of some promising network-based devices are modified by random (spin-dependent) scattering events and by thermal fluctuations. It is found that although the functionality of these devices is obviously based on the quantum coherence of the transmitted electrons, there is a certain stability: moderate level of errors can be tolerated. For mesoscopic networks made of typical semiconductor materials, we found that when the energy distribution of the input carriers is narrow enough, the devices can operate close to their ideal limits even at relatively high temperature. As an example, we present results for two different networks: one that realizes a Stern-Gerlach device and another that simulates a spin quantum walker. Finally we propose a simple network that can act as a narrow band energy filter even in the presence of random scatterers.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 41
DOI: 10.1103/PhysRevB.80.125324
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“Structure of binary colloidal systems confined in a quasi-one-dimensional channel”. Yang W, Nelissen K, Kong M, Zeng Z, Peeters FM, Physical review : E : statistical physics, plasmas, fluids, and related interdisciplinary topics 79, 041406 (2009). http://doi.org/10.1103/PhysRevE.79.041406
Abstract: The structural properties of a binary colloidal quasi-one-dimensional system confined in a narrow channel are investigated through modified Monte Carlo simulations. Two species of particles with different magnetic moment interact through a repulsive dipole-dipole force are confined in a quasi-one-dimensional channel. The impact of three decisive parameters (the density of particles, the magnetic-moment ratio, and the fraction between the two species) on the transition from disordered phase to crystal-like phases and the transitions among the different mixed phases are summarized in a phase diagram.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.366
Times cited: 11
DOI: 10.1103/PhysRevE.79.041406
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“Superconducting nanowires: interplay of discrete transverse modes with supercurrent”. Croitoru MD, Shanenko AA, Kaun CC, Peeters FM, Physical review : B : solid state 80, 024513 (2009). http://doi.org/10.1103/PhysRevB.80.024513
Abstract: From a numerical solution of the Bogoliubov-de Gennes equations, we investigate an interplay of the transverse discrete modes with a longitudinal supercurrent in a metallic cylindrical superconducting nanowire. The superconductor-to-normal transition induced by a longitudinal superflow of electrons is found to occur as a cascade of jumps in the order parameter (supercurrent and superfluid density) as a function of the superfluid velocity for diameters d<1015 nm (for Al parameters) and sufficiently low temperatures T<0.30.4Tc, with Tc the critical temperature. When approaching Tc, the jumps are smoothed into steplike but continuous drops. A similar picture occurs for d>1520 nm. Only when the diameter exceeds 5070 nm the quantum-size cascades are fully washed out, and we arrive at the mesoscopic regime. Below this regime the critical current density jc exhibits the quantum-size oscillations with pronounced resonant enhancements: the smaller the diameter, the more significant is the enhancement. Thickness fluctuations of real samples will smooth out such oscillations into an overall growth of jc with decreasing nanowire diameter.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 21
DOI: 10.1103/PhysRevB.80.024513
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“Superconducting nanowires: quantum confinement and spatially dependent Hartree-Fock potential”. Chen Y, Croitoru MD, Shanenko AA, Peeters FM, Journal of physics : condensed matter 21, 435701 (2009). http://doi.org/10.1088/0953-8984/21/43/435701
Abstract: It is well known that, in bulk, the solution of the Bogoliubovde Gennes equations is the same whether or not the HartreeFock term is included. Here the HartreeFock potential is position independent and so gives the same contribution to both the single-electron energies and the Fermi level (the chemical potential). Thus, the single-electron energies measured from the Fermi level (they control the solution) stay the same. This is not the case for nanostructured superconductors, where quantum confinement breaks the translational symmetry and results in a position-dependent HartreeFock potential. In this case its contribution to the single-electron energies depends on the relevant quantum numbers. We numerically solved the Bogoliubovde Gennes equations with the HartreeFock term for a clean superconducting nanocylinder and found a shift of the curve representing the thickness-dependent oscillations of the critical superconducting temperature to larger diameters.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Impact Factor: 2.649
Times cited: 12
DOI: 10.1088/0953-8984/21/43/435701
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“Superconducting nanowires: quantum-confinement effect on the critical magnetic field and supercurrent”. Croitoru MD, Shanenko AA, Peeters FM, International journal of modern physics: B: condensed matter physics, statistical physics, applied physics
T2 –, 32nd International Workshop on Condensed Matter Theories, Aug 12-19, 2008, Loughborough Univ, Loughborough, England 23, 4257 (2009). http://doi.org/10.1142/S0217979209063419
Abstract: We study the effect of electron confinement on the superconducting-to-normal phase transition driven by a magnetic field and/or on the current-carrying state of the superconducting condensate in nanowires. Our investigation is based on a self-consistent numerical solution of the Bogoliubov-de Gennes equations. We show that in a parallel magnetic field and/or in the presence of supercurrent the transition from superconducting to normal phase occurs as a cascade of discontinuous jumps in the superconducting order parameter for diameters D < 10 divided by 15 nm at T = 0. The critical magnetic field exhibits quantum-size oscillations with pronounced resonant enhancements.
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT)
Impact Factor: 0.736
Times cited: 1
DOI: 10.1142/S0217979209063419
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“Terahertz absorption window in bilayer graphene”. Dong HM, Qin H, Zhang J, Peeters FM, Xu W Ieee, New York, N.Y., page 247 (2009).
Abstract: We present a detailed theoretical study of terahertz (THz) optical absorption in bilayer graphene. Considering an air/graphene/dielectric-wafer system, we find that there is an absorption window in the range 3 similar to 30 THz. Such an absorption window is induced by different transition energies required for inter- and intra-band optical absorption in the presence of the Pauli blockade effect. As a result, the position and width of this THz absorption window depend sensitively on temperature and carrier density of the system. These results are pertinent to the applications of recently developed graphene systems as novel optoelectronic devices such as THz photo-detectors.
Keywords: H1 Book chapter; Condensed Matter Theory (CMT)
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“Transverse instabilities of multiple vortex chains in magnetically coupled NbSe2/permalloy superconductor/ferromagnet bilayers”. Karapetrov G, Milošević, MV, Iavarone M, Fedor J, Belkin A, Novosad V, Peeters FM, Physical review : B : solid state 80, 180506 (2009). http://doi.org/10.1103/PhysRevB.80.180506
Abstract: Using scanning tunneling microscopy and Ginzburg-Landau simulations, we explore vortex configurations in magnetically coupled NbSe2/permalloy superconductor/ferromagnet bilayer. The permalloy film with stripe domain structure induces periodic local magnetic induction in the superconductor, creating a series of pinning-antipinning channels for externally added magnetic flux quanta. Such laterally confined Abrikosov vortices form quasi-one-dimensional arrays (chains). The transitions between multichain states occur through propagation of kinks at the intermediate fields. At high fields we show that the system becomes nonlinear due to a change in both the number of vortices and the confining potential. The longitudinal instabilities of the resulting vortex structures lead to vortices levitating in the antipinning channels.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 38
DOI: 10.1103/PhysRevB.80.180506
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“Tunable kinematics of phase-slip lines in a superconducting stripe with magnetic dots”. Berdiyorov GR, Milošević, MV, Peeters FM, Physical review : B : solid state 80, 214509 (2009). http://doi.org/10.1103/PhysRevB.80.214509
Abstract: Using numerical simulations, we study the dynamic properties of a superconducting stripe with a perpendicular magnetized ferromagnet on top in the presence of an applied dc current. In the resistive state conventional phase-slip lines are transformed into kinematic vortex-antivortex pairs with special dynamic behavior. In addition, the location of phase slippage in the sample is predetermined by the position of the magnetic dot. Both these effects directly influence the dynamics of the superconducting condensate and lead to periodic oscillations of the voltage across the sample with a frequency tunable both by the applied current and by the magnetization of the magnet. We found that the frequency of the voltage oscillations increases with increasing number of magnetic dots.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 33
DOI: 10.1103/PhysRevB.80.214509
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“Tuning the superconducting properties of nanomaterials”. Croitoru MD, Shanenko AA, Peeters FM Springer, Dordrecht, page 1 (2009).
Abstract: Electron continement and its effect on the superconducting-to-normal phase transition driven by a magentic field and/or a current is studied in nanowires. Our investigation is based on a self-consistent numerical solution of the Bogoliubov-de Gennes equations. We find that in a parallel magneitc field and/or in the presence of a supercurrent the transition from the superconducting to the normal phase occurs as a cascade of discontinuous jumps in the superconducting order parameter for diameters D < 10 divided by 15 nm at T = 0. The critical magentic field exhibits quantum-size oscillations with pronounced resonant enhancements as a function of the wire radius.
Keywords: H1 Book chapter; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT)
DOI: 10.1007/978-90-481-3120-4_1
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“Tunneling, conductance, and wavevector filtering through magnetic barriers in bilayer graphene”. Masir MR, Vasilopoulos P, Peeters FM, Physical review : B : solid state 79, 035409 (2009). http://doi.org/10.1103/PhysRevB.79.035409
Abstract: We evaluate the transmission and conductance through magnetic barrier structures in bilayer graphene. In particular we consider a magnetic step, single and double barriers, -function barriers, as well as barrier structures that have average magnetic field equal to zero. The transmission depends strongly on the direction of the incident electron or hole wavevector and gives the possibility to construct a direction-dependent wavevector filter. The results contrast sharply with previous results on single-layer graphene. In general, the angular range of perfect transmission becomes drastically wider and the gaps narrower. This perfect transmission range decreases with the number of barriers, the barrier width, and the magnetic field. Depending on the structure, a variety of transmission resonances occur that are reflected in the conductance through the structure.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 80
DOI: 10.1103/PhysRevB.79.035409
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“Unconventional vortex dynamics in mesoscopic superconducting corbino disks”. Lin NS, Misko VR, Peeters FM, Physical review letters 102, 197003 (2009). http://doi.org/10.1103/PhysRevLett.102.197003
Abstract: The discrete shell structure of vortex matter strongly influences the flux dynamics in mesoscopic superconducting Corbino disks. While the dynamical behavior is well understood in large and in very small disks, in the intermediate-size regime it occurs to be much more complex and unusual, due to (in)commensurability between the vortex shells. We demonstrate unconventional vortex dynamics (inversion of shell velocities with respect to the gradient driving force) and angular melting (propagating from the boundary where the shear stress is minimum, towards the center) in mesoscopic Corbino disks.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 8.462
Times cited: 18
DOI: 10.1103/PhysRevLett.102.197003
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