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“Thermally induced structural and morphological changes of CdSe/CdS octapods”. Goris B, van Huis MA, Bals S, Zandbergen HW, Manna L, Van Tendeloo G, Small 8, 937 (2012). http://doi.org/10.1002/smll.201101897
Abstract: Branched nanostructures are of great interest because of their promising optical and electronic properties. For successful and reliable integration in applications such as photovoltaic devices, the thermal stability of the nanostructures is of major importance. Here the different domains (CdSe cores, CdS pods) of the heterogeneous octapods are shown to have different thermal stabilities, and heating is shown to induce specific shape changes. The octapods are heated from room temperature to 700 °C, and investigated using (analytical and tomographic) transmission electron microscopy (TEM). At low annealing temperatures, pure Cd segregates in droplets at the outside of the octapods, indicating non-stochiometric composition of the octapods. Furthermore, the tips of the pods lose their faceting and become rounded. Further heating to temperatures just below the sublimation temperature induces growth of the zinc blende core at the expense of the wurtzite pods. At higher temperatures, (500700 °C), sublimation of the octapods is observed in real time in the TEM. Three-dimensional tomographic reconstructions reveal that the four pods pointing into the vacuum have a lower thermal stability than the four pods that are in contact with the support.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 8.643
Times cited: 20
DOI: 10.1002/smll.201101897
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“Analytical TEM study of CVD diamond growth on TiO2 sol-gel layers”. Lu Y-G, Verbeeck J, Turner S, Hardy A, Janssens SD, De Dobbelaere C, Wagner P, Van Bael MK, Van Tendeloo G, Diamond and related materials 23, 93 (2012). http://doi.org/10.1016/j.diamond.2012.01.022
Abstract: The early growth stages of chemical vapor deposition (CVD) diamond on a solgel TiO2 film with buried ultra dispersed diamond seeds (UDD) have been studied. In order to investigate the diamond growth mechanism and understand the role of the TiO2 layer in the growth process, high resolution transmission electron microscopy (HRTEM), energy-filtered TEM and electron energy loss spectroscopy (EELS) techniques were applied to cross sectional diamond film samples. We find evidence for the formation of TiC crystallites inside the TiO2 layer at different diamond growth stages. However, there is no evidence that diamond nucleation starts from these crystallites. Carbon diffusion into the TiO2 layer and the chemical bonding state of carbon (sp2/sp3) were both extensively investigated. We provide evidence that carbon diffuses through the TiO2 layer and that the diamond seeds partially convert to amorphous carbon during growth. This carbon diffusion and diamond to amorphous carbon conversion make the seed areas below the TiO2 layer grow and bend the TiO2 layer upwards to form the nucleation center of the diamond film. In some of the protuberances a core of diamond seed remains, covered by amorphous carbon. It is however unlikely that the remaining seeds are still active during the growth process.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.561
Times cited: 16
DOI: 10.1016/j.diamond.2012.01.022
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“Quenching of the Hall effect in localised high magnetic field regions”. Novoselov KS, Geim AK, Dubonos SV, Cornelissens YG, Peeters FM, Maan JC, Physica. E: Low-dimensional systems and nanostructures 12, 244 (2002). http://doi.org/10.1016/S1386-9477(01)00364-2
Abstract: We report the suppression of the Hall effect in a mesoscopic Hall cross with a strong magnetic field only in the centre and vanishingly small outside, The local magnetic field is produced by placing Dy pillar on top of a structure with a high-mobility two-dimensional electron gas. The effect is found to be due to a sharp increase of the number of back-scattered and quasi-localised electron orbits. The possibility of localising electrons inside the magnetic inhomogeneity region is discussed. (C) 2002 Elsevier Science B.V. All rights reserved.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.221
Times cited: 3
DOI: 10.1016/S1386-9477(01)00364-2
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“Quantum-confined magneto-Stark effect in diluted magnetic semiconductor coupled quantum wells”. Chang K, Xia JB, Wu HB, Feng SL, Peeters FM, Applied physics letters 80, 1788 (2002). http://doi.org/10.1063/1.1459491
Abstract: The magneto-Stark effect in a diluted magnetic semiconductor (DMS) coupled quantum well (CQW) induced by an in-plane magnetic field is investigate theoretically. Unlike the usual electro-Stark effects, in a DMS CQW the Lorenz force leads to a spatially separated exciton. The in-plane magnetic field can shift the ground state of the magnetoexciton from a zero in-plane center of mass (CM)/momentum to a finite CM momentum, and render the ground state of magnetoexciton stable against radiative recombination due to momentum conservation. (C) 2002 American Institute of Physics.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.411
Times cited: 8
DOI: 10.1063/1.1459491
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“Magnetic coupling between mesoscopic superconducting rings”. Baelus BJ, Yampolskii SV, Peeters FM, Physica: C : superconductivity 369, 366 (2002). http://doi.org/10.1016/S0921-4534(01)01278-3
Abstract: Using the nonlinear Ginzburg-Landau theory we investigated the dependence of the magnetic coupling between two concentric mesoscopic superconducting rings on their thickness. The size of this magnetic coupling increases with the thickness of the rings. (C) 2001 Elsevier Science B.V. All rights reserved.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.404
Times cited: 1
DOI: 10.1016/S0921-4534(01)01278-3
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“Giant vortices in small mesoscopic disks : an approximate description”. Yampolskii SV, Peeters FM, Physica: C : superconductivity 369, 347 (2002). http://doi.org/10.1016/S0921-4534(01)01274-6
Abstract: We present an approximate description of the giant vortex state in a thin mesoscopic superconducting disk within the phenomenological Ginzburg-Landau approach. Analytical asymptotic expressions for the energies of the states with fixed vorticity are obtained when a small magnetic flux is accumulated in the disk. The spectrum of the lowest Landau levels of such a disk is also discussed. (C) 2001 Elsevier Science B.V. All rights reserved.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.404
DOI: 10.1016/S0921-4534(01)01274-6
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“Joule heat in a two-dimensional electron gas exposed to a normal non-homogeneous magnetic field of a 'chess' configuration”. Badalyan SM, Peeters FM, Physica: B : condensed matter 316, 216 (2002). http://doi.org/10.1016/S0921-4526(02)00462-3
Abstract: We have calculated analytically the spatial distribution of the electric field and current density, and obtained the Joule heat generation rate in a two-dimensional electron gas (2DEG) subjected to a non-homogeneous magnetic field of a 'chess' configuration. The generation of the Joule heat from the 2DEG is mainly concentrated near the singular corners of each 'chess' field and tends to zero in other corners. (C) 2002 Elsevier Science B.V. All rights reserved.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.386
DOI: 10.1016/S0921-4526(02)00462-3
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“Exciton trapping in a periodically modulated magnetic field”. Freire JAK, Freire VN, Farias GA, Peeters FM, Brazilian journal of physics 32, 310 (2002). http://doi.org/10.1590/S0103-97332002000200016
Abstract: The behavior of excitons in spatially modulated magnetic fields is described taking into account the exciton spin contribution. The results show that the exciton trapping in periodic magnetic fields is possible and dependent on the modulation profile.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 0.732
Times cited: 1
DOI: 10.1590/S0103-97332002000200016
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“Coupled mesoscopic superconductors : Ginzburg-Landau theory”. Baelus BJ, Yampolskii SV, Peeters FM, Physical review : B : condensed matter and materials physics 66, 024517 (2002). http://doi.org/10.1103/PhysRevB.66.024517
Abstract: The magnetic coupling between two concentric mesoscopic superconductors with nonzero thickness is studied using the nonlinear Ginzburg-Landau theory. We calculated the free energy, the expelled field, the total field profile, the Cooper-pair density, and the current density distribution. By putting a smaller superconducting disk or ring in the center of a larger ring, the properties change drastically. Extra ground-state transitions are found, where the total vorticity stays the same, but the vorticity of the inner superconductor changes by 1. Due to the magnetic coupling, the current in the external ring exhibits extra jumps at the transition fields where the vorticity of the inner superconductor changes. In this case, for certain temperatures, re-entrant behavior and switching on and off of the superconducting behavior of the rings are found as a function of the magnetic field. A H-T phase diagram is obtained for the situation where the inner ring has a higher critical temperature than the outer ring. An analytic expression for the magnetic coupling is obtained for thin rings and extreme type-II superconductors.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 11
DOI: 10.1103/PhysRevB.66.024517
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“Even-odd transition in the Shubnikov-de Haas oscillations in a two-dimensional electron gas subjected to periodic magnetic and electric modulations”. Shi J, Peeters FM, Edmonds KW, Gallagher BL, Physical review : B : condensed matter and materials physics 66, 035328 (2002). http://doi.org/10.1103/PhysRevB.66.035328
Abstract: We investigate low-temperature magnetotransport of high-mobility two-dimensional electron gases subjected to one-dimensional periodic magnetic and electric modulations. Our previous quantum perturbation theory is extended to lower temperatures and the energy broadening due to impurity scattering is incorporated. Numerical calculations are made for situations where several Landau bands overlap. We find that the Shubnikov-de Haas (SdH) oscillations are dominated by collisional resistance. The amplitudes of the SdH oscillations are strongly modulated and the positions of the SdH minima switch between even and odd Landau-level filling factors, in the resistance both parallel and perpendicular to the one-dimensional modulation. This is a consequence of the internal structure (i.e., smeared out van Hove singularities) of overlapping Landau bands. Our theoretical results are in good agreement with recent experiments.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 32
DOI: 10.1103/PhysRevB.66.035328
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“Dynamic transitions between metastable states in a superconducting ring”. Vodolazov DI, Peeters FM, Physical review : B : condensed matter and materials physics 66, 054537 (2002). http://doi.org/10.1103/PhysRevB.66.054537
Abstract: Applying the time-dependent Ginzburg-Landau equations, transitions between metastable states of a superconducting ring are investigated in the presence of an external magnetic field. It is shown that if the ring exhibits several metastable states at a particular magnetic field, the transition from one metastable state to another one is governed by both the relaxation time of the absolute value of the order parameter tau(\psi\) and the relaxation time of the phase of the order parameter tau(phi). We found that the larger the ratio tau(\psi\)/tau(phi), the closer the final state will be to the absolute minimum of the free energy, i.e., the thermodynamic equilibrium. The transition to the final state occurs through a subsequent set of single phase slips at a particular point along the ring.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 34
DOI: 10.1103/PhysRevB.66.054537
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“Far-infrared spectroscopy of minibands and confined donors in GaAs/AlxGa1-xAs superlattices”. Helm M, Peeters FM, DeRosa F, Colas E, Harbison JP, Florez LT, Physical review : B : condensed matter and materials physics 43, 13983 (1991)
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.736
Times cited: 77
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“MgB2 : superconductivity and pressure effects”. Ivanov VA, Betouras JJ, Peeters FM, , 35 (2003)
Abstract: We present a Ginzburg-Landau theory for a two-band superconductor with emphasis on MgB2. We propose experiments which lead to identification of the possible scenarios: whether both sigma- and pi-bands superconduct or sigma-alone. According to the second scenario a microscopic theory of superconducting MgB2 is proposed based on the strongly interacting or-electrons and non-correlated pi-electrons of boron ions. The kinematic and Coulomb interactions of sigma-electrons provide the superconducting state with an anisotropic gap of s(*)-wave symmetry. The critical temperature T-c has a non-monotonic dependence on the distance r between the centers of gravity of sigma- and pi-bands. The position of MgB2 on a bell-shaped curve T-c (r) is identified in the overdoped region. The derived superconducting density of electronic states is in agreement with available experimental and theoretical data. It is argued that the effects of pressure are crucial to identify the microscopic origin of superconductivity in MgB2. Possibilities for increase of T, are discussed.
Keywords: P1 Proceeding; Condensed Matter Theory (CMT)
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“Structural characterization of nanostructured Ni3Al processed by inert gas condensation”. Yandouzi M, Pauwels B, Schryvers D, Van Swygenhoven H, Van Tendeloo G, Diffusion and defect data : solid state data : part A : defect and diffusion forum 213, 19 (2003)
Abstract: High-resolution transmission electron microscopy was performed on compacted Ni(3)Al nanostructured material prepared by the inert gas condensation technique. From electron diffraction data an incomplete L1(2) ordering of the crystallites is observed in the free particles as well as in the room temperature compacted samples. However, a completely ordered L1(2) structure with much bigger and well-defined crystallites exhibiting several defects is observed in material compacted and annealed at 773 K. Sharp crystallite boundaries as well as amorphous material and voids are observed in between crystallites in all samples, the former being dominant in the annealed material, the latter in the as-prepared one.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
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“Ginzburg-Landau theory and effects of pressure on a two-band superconductor : application to MgB2”. Betouras JJ, Ivanov VA, Peeters FM, European physical journal : B : condensed matter and complex systems 31, 349 (2003). http://doi.org/10.1140/epjb/e2003-00041-7
Abstract: We present a model of pressure effects of a two-band superconductor based on a Ginzburg-Landau free energy with two order parameters. The parameters of the theory are pressure as well as temperature dependent. New pressure effects emerge as a result of the competition between the two bands. The theory then is applied to MgB2. We identify two possible scenaria regarding the fate of the two Q subbands under pressure, depending on whether or not both subbands are above the Fermi energy at ambient pressure. The splitting of the two subbands is probably caused by the E-2g, distortion. If only one subband is above the Fermi energy at ambient pressure (scenario I), application of pressure diminishes the splitting and it is possible that the lower subband participates in the superconductivity. The corresponding crossover pressure and Gruneisen parameter are estimated. In the second scenario both bands start above the Fermi energy and they move below it, either by pressure or via the substitution of Mg by Al. In both scenaria, the possibility of electronical topological transition is emphasized. Experimental signatures of both scenaria are presented and existing experiments are discussed in the light of the different physical pictures.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.461
Times cited: 10
DOI: 10.1140/epjb/e2003-00041-7
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“Ordering of tetrahedral chains in the Sr2MnGaO5 brownmillerite”. Abakumov AM, Alekseeva AM, Rozova MG, Antipov EV, Lebedev OI, Van Tendeloo G, Journal of solid state chemistry 174, 319 (2003). http://doi.org/10.1016/S0022-4596(03)00226-3
Abstract: Tetrahedral chain ordering in the Sr2MnGaO5 structure is studied using electron diffraction (ED) and high-resolution electron microscopy. The ED patterns show the presence of satellite reflections, which indicate a commensurately modulated structure with a = 5.4056(8) Angstrom b 16.171(3) Angstrom, c = 5.5592(7) Angstrom, q – 1/2c*, superspace group Immma(00gamma,)s00. The Superstructure arises due to ordering of the two types of symmetry related tetrahedral chains (L and R) according to a ... LRLR ... sequence, where L and R chains alternate along the c-axis within the same (GaO) layer. Numerous defects at different structural levels were observed, comprising interleaving L and R chains, violation of the ... LRLR ... chain sequence within one layer, different stacking modes of the ... LRLR ... ordered layers with subsequent alternation of blocks of different width along the h-axis of the brownmillerite subcell and island fragmentation of the modulated superstructure. By in situ heating ED experiments it is found that the long-range ordering of the tetrahedral chains is stable tip to 665degreesC and is completely suppressed at 905degreesC. (C) 2003 Elsevier Inc. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.299
Times cited: 34
DOI: 10.1016/S0022-4596(03)00226-3
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“Optical bistability and multistability in four-level systems”. Chen Z, Feng X, Xu Y, Yu MY, Physica scripta 68, 199 (2003). http://doi.org/10.1238/Physica.Regular.068a00199
Abstract: The optical behavior of a four-level system in a ring cavity driven by two coherent laser fields is studied. One laser field is treated as the incident field and the other the control field, respectively. It is found that there is optical transparency when the difference between the two frequency detunings of the incident and control fields from the corresponding atomic transition frequencies is zero. Optical bistability can be produced and controlled by increasing the magnitude of the frequency difference. The bistable hysteresis becomes larger when the frequency difference is increased. Further increase of the latter can lead to onset of multistability.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 1.28
Times cited: 8
DOI: 10.1238/Physica.Regular.068a00199
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“The hot electron distribution of two-dimensional electrons in a polar semiconductor at zero temperature”. Xu W, Peeters FM, Devreese JT, Journal of physics: C: condensed matter 3, 1783 (1991)
Keywords: A3 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Times cited: 1
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“Spin-dependent transmission through a chain of rings : influence of a periodically modulated spin-orbit interaction strength or ring radius”. Molnar B, Vasilopoulos P, Peeters FM, Applied physics letters 85, 612 (2004). http://doi.org/10.1063/1.1775283
Abstract: We study ballistic electron transport through a finite chain of quantum circular rings in the presence of spin-orbit interaction of strength alpha. For a single ring, the transmission and reflection coefficients are obtained analytically and from them the conductance for a chain of rings as a function of alpha and of the wave vector k of the incident electron. We show that due to destructive spin interferences, the chain can be totally opaque for certain ranges of k, the width of which depends on the value of alpha. A periodic modulation of the strength alpha or of the ring radius widens the gaps considerably and produces a nearly binary conductance output. (C) 2004 American Institute of Physics.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.411
Times cited: 26
DOI: 10.1063/1.1775283
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“Magnetoconductance through a chain of rings in the presence of spin-orbit interaction”. Vasilopoulos P, Molnar B, Peeters FM, International journal of modern physics: B: condensed matter physics, statistical physics, applied physics 18, 3661 (2004). http://doi.org/10.1142/S0217979204027244
Abstract: Ballistic electron transport through a finite chain of quantum circular rings is studied in the presence of the Rashba coupling, of strength a, and of a perpendicular magnetic field B. The transmission and reflection coefficients for a single ring, obtained analytically, help obtain the conductance through a chain of rings as a function of the strength a, the field B, and of the wave vector k of the incident electron. Due to destructive spin interferences caused by the Rashba coupling the chain can be totally opaque for certain ranges of k the width of which depends on values of a and B. Outside these ranges the conductance oscillates with high values between e(2)/h and 2e(2)/h. The effect of a periodic modulation of a or B on the conductance gaps is investigated. A periodic, square-wave conductance pattern, pertinent to the development of the spin transistor, results within wide stripes in the parameter space spanned by k, a, and B. Finite temperatures smoothen the square-wave profile of the conductance but do not alter its periodic character.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 0.736
Times cited: 2
DOI: 10.1142/S0217979204027244
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“Transmission electron microscopy characterisation of Ti and Al/Ti contacts on GaN and AlGaN/GaN”. van Daele B, Van Tendeloo G, Ruythooren W, Derluyn J, Leys MR, Germain M, Springer proceedings in physics 107, 389 (2005)
Abstract: Transmission electron microscopy has been applied to study Ti and Al/Ti contacts on GaN and AlGaN/GaN as a function of annealing temperature. This has lead to a profound understanding of the role of Al, both in the contact formation on n-GaN and on AlGaN/GaN. Al in the AlGaN decreases the N-extraction by Ti out of the nitride, because of the strong Al-N bond. Al in the metal bilayer also reduces the N-extraction by Ti due to a preferential alloy mixing.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
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“Square-wave conductance through a chain of rings due to spin-orbit interaction”. Molnar B, Vasilopoulos P, Peeters FM, AIP conference proceedings 772, 1335 (2005)
Abstract: We study ballistic electron transport through a finite chain of quantum circular rings in the presence of spin-orbit interaction (SOI) of strength alpha. The transmission and reflection coefficients for a single ring, obtained analytical lylead to the conductance for a chain of rings as a function of alpha and of the wave vector k of the incident electron. Due to destructive spin interferences the chain can be totaly opaque for certain ranges of k the width of which depends on the value of alpha. A periodic modulation of a widens up the gaps considerably and produces a nearly binary conductance output.
Keywords: P1 Proceeding; Condensed Matter Theory (CMT)
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“Reentrant melting of a classical two-dimensional binary cluster”. Nelissen K, Heytens L, Schweigert VA, Peeters FM, AIP conference proceedings 799, 347 (2005)
Abstract: A system of classical charged particles interacting through a dipole repulsive potential, which are confined in a two-dimensional hardwall trap, is studied. The cluster consists of 16 particles, together with 4 defect particles. The technique of Brownian dynamics is used to simulate experimental binary colloidal systems [1]. The melting properties and the reentrant behavior of the system, which was studied before for clusters of identical particles [2], are studied for the binary mixture. The defect particles, which have a smaller charge than the other particles, stabilize the cluster, melt at a higher value of the coupling parameter F as compared to the other particles and have a strong influence on the melting properties of the other particles.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
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“Observation of paramagnetic supercurrent in mesoscopic superconducting rings and disks using multiple-small-tunnel-junction method”. Kanda A, Baelus BJ, Peeters FM, Kadowaki K, Ootuka Y, , 204 (2005). http://doi.org/10.1142/9789812701619_0032
Abstract: Responses of mesoscopic superconducting rings and disks to perpendicular magnetic fields are studied by using the multiple-small-tunnel-junction method, in which transport properties of several small tunnel junctions attached to the sample are measured simultaneously. This allows us for a direct experimental observation of the paramagnetic supercurrent, which is closely related to the paramagnetic Meissner effect. The results are compared with numerical results based on the nonlinear Ginzburg-Landau theory.
Keywords: P1 Proceeding; Condensed Matter Theory (CMT)
DOI: 10.1142/9789812701619_0032
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“Classical nature of quantum dots in a magnetic field”. Anisimovas E, Matulis A, Peeters FM, Acta physica Polonica: A: general physics, solid state physics, applied physics 107, 188 (2005)
Abstract: A quasiclassical theory of few-electron quantum dots in a strong magnetic field is developed. The ground state energy and the corresponding many-electron wave function are obtained and used to derive a universal relation of critical magnetic fields and calculate the currents and the density-current correlation function.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 0.469
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“Intersublevel absorption in stacked n-type doped self-assembled quantum dots”. Veljkovic D, Tadić, M, Peeters FM, Materials science forum 494, 37 (2005)
Abstract: The intersublevel absorption in n-doped InAs/GaAs self-assembled quantum-dot molecules composed of three quantum dots is theoretically considered. The transition matrix elements and the transition energies are found to vary considerably with the spacer thickness. For s polarized light, decreasing the thickness of the spacer between the dots brings about crossings between the transition matrix elements, but the overall absorption is not affected by the variation of the spacer thickness. For p-polarized light and thick spacers, there are no available transitions in the single quantum dot, but a few of them emerge as a result of the electron state splitting in the stacks of coupled quantum dots, which leads to a considerable increase of the transition matrix elements, exceeding by an order of magnitude values of the matrix elements for s-polarized light.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
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“Bound states and lifetime of an electron on a bulk helium surface”. Degani MH, Farias GA, Peeters FM, Physical review : B : condensed matter and materials physics 72, 125408 (2005). http://doi.org/10.1103/PhysRevB.72.125408
Abstract: We propose an effective potential for an excess electron near the helium liquid-vapor interface that takes into account the diffuseness of the liquid-vapor interface and the classical image potential. The splitting of the first two excited states of the excess electron bound to the helium liquid-vapor interface as a function of an external constant electric field applied perpendicular to the interface is in excellent agreement with recent experiments. The effect of a parallel magnetic field on the energy levels are calculated. Single-electron tunneling of the electron out of its surface state is studied as a function of the electric field applied to the system. We found that the tunneling time has a linear dependence on the electric field.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 11
DOI: 10.1103/PhysRevB.72.125408
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“Influence of surface defects on the vortex transitions in mesoscopic superconductors”. Baelus BJ, Kadowaki K, Peeters FM, AIP conference proceedings 850, 745 (2006)
Abstract: Solving the nonlinear Ginzburg-Landau equations self-consistently, we investigate the influence of a triangular surface defect (i.e. pacman shaped sample) on the vortex transitions in mesoscopic superconducting disks. Depending on the size of the defect, vortices may enter/leave one by one or in pairs.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
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“Terahertz radiation from crystals of nanomagnets”. Benedict MG, Földi P, Peeters FM, Journal of physics : conference series 36, 12 (2006). http://doi.org/10.1088/1742-6596/36/1/003
Abstract: Certain crystals, consisting of molecules with unusually large spin, exhibit macroscopically observable signatures of quantum tunneling, when a slowly varying external magnetic field is applied parallel to the easy axis of the crystal. Recently it has been observed that jumps in the magnetization are sometimes accompanied by the emission of infrared radiation. We discuss the connection of the tunneling with the electromagnetic transition, and we address the questions: to what extent can the radiation be considered as a collective, superradiant emission, and what is the role played by the cavity in the experiments? Our conclusion is that among the reported experimental coditions the radiation is not superradidance, but rather a maserlike effect.
Keywords: P1 Proceeding; Condensed Matter Theory (CMT)
Times cited: 1
DOI: 10.1088/1742-6596/36/1/003
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“Single crystalline GaN grown on porous Si(111) by MOVPE”. Cheng K, Degroote S, Leys M, van Daele B, Germain M, Van Tendeloo G, Borghs G, Physica status solidi: C: conferences and critical reviews 4, 1908 (2007). http://doi.org/10.1002/pssc.200674316
Abstract: In this work, GaN growth on porous Si(111) will be reported. The porosity of the substrates was 30% or 50%. In the latter case, various thicknesses, from 0.6 mu m to 10 mu m, were investigated. The morphology of the GaN surfaces was analyzed by optical interference microscopy. The crystalline quality of the epitaxial layers was characterized by High Resolution X-Ray Diffraction (HR-XRD) and cross-sectional Transmission Electron Microscopy (TEM). A Full Width at Half Maximum (FWHM) of the X-ray symmetric rocking curve (0002) 2 theta – omega scan of 290 arc see was obtained for a 1 mu m thick GaN layer, which is comparable with that of GaN grown on bulk Si(111) substrates. (c) 2007 WILEY-VCH Verlag GmbH Co. KGaA, Weinheim.
Keywords: P1 Proceeding; Electron microscopy for materials research (EMAT)
Times cited: 2
DOI: 10.1002/pssc.200674316
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