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Author Van Passel, S.; Van Huylenbroeck, G.; Lauwers, L.; Mathijs, E.
Title Sustainable value assessment of farms using frontier efficiency benchmarks Type A1 Journal article
Year 2009 Publication Journal Of Environmental Management Abbreviated Journal J Environ Manage
Volume 90 Issue 10 Pages 3057-3069
Keywords (down) A1 Journal article; Economics
Abstract Appropriate assessment of firm sustainability facilitates actor-driven processes towards sustainable development. The methodology in this paper builds further on two proven methodologies for the assessment of sustainability performance: it combines the sustainable value approach with frontier efficiency benchmarks. The sustainable value methodology tries to relate firm performance to the use of different resources. This approach assesses contributions to corporate sustainability by comparing firm resource productivity with the resource productivity of a benchmark, and this for all resources considered. The efficiency is calculated by estimating the production frontier indicating the maximum feasible production possibilities. In this research, the sustainable value approach is combined with efficiency analysis methods to benchmark sustainability assessment. In this way, the production theoretical underpinnings of efficiency analysis enrich the sustainable value approach. The methodology is presented using two different functional forms: the CobbDouglas and the translog functional forms. The simplicity of the CobbDouglas functional form as benchmark is very attractive but it lacks flexibility. The translog functional form is more flexible but has the disadvantage that it requires a lot of data to avoid estimation problems. Using frontier methods for deriving firm specific benchmarks has the advantage that the particular situation of each company is taken into account when assessing sustainability. Finally, we showed that the methodology can be used as an integrative sustainability assessment tool for policy measures.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000269022800013 Publication Date 2009-06-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0301-4797 ISBN Additional Links UA library record; WoS full record; WoS citing articles; WoS full record; WoS citing articles
Impact Factor 4.01 Times cited 41 Open Access
Notes Approved Most recent IF: 4.01; 2009 IF: 2.367
Call Number UA @ admin @ c:irua:136762 Serial 6259
Permanent link to this record
 
 
Author Brosens, F.; Magnus, W.
Title Carrier transport in nanodevices: revisiting the Boltzmann and Wigner distribution functions Type A1 Journal article
Year 2009 Publication Physica status solidi: B: basic research Abbreviated Journal Phys Status Solidi B
Volume 246 Issue 7 Pages 1656-1661
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Abstract In principle, transport of charged carriers in nanometer sized solid-state devices can be fully characterized once the non-equilibrium distribution function describing the carrier ensemble is known. In this light, we have revisited the Boltzmann and the Wigner distribution functions and the framework in which they emerge from the classical respectively quantum mechanical Liouville equation. We have assessed the method of the characteristic curves as a potential workhorse to solve the time dependent Boltzmann equation for carriers propagating through spatially non-uniform systems, such as nanodevices. In order to validate the proposed solution strategy, we numerically solve the Boltzmann equation for a one-dimensional conductor mimicking the basic features of a biased low-dimensional transistor operating in the on-state. Finally, we propose a computational scheme capable of extending the benefits of the above mentioned solution strategy when it comes to solve the Wigner-Liouville equation.
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Corporate Author Thesis
Publisher Place of Publication Berlin Editor
Language Wos 000268659100033 Publication Date 2009-04-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-1972;1521-3951; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.674 Times cited 8 Open Access
Notes Approved Most recent IF: 1.674; 2009 IF: 1.150
Call Number UA @ lucian @ c:irua:77953 Serial 284
Permanent link to this record
 
 
Author Magnus, W.; Brosens, F.; Sorée, B.
Title Modeling drive currents and leakage currents : a dynamic approach Type A1 Journal article
Year 2009 Publication Journal of computational electronics Abbreviated Journal J Comput Electron
Volume 8 Issue 3/4 Pages 307-323
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Abstract The dynamics of electrons and holes propagating through the nano-scaled channels of modern semiconductor devices can be seen as a widespread manifestation of non-equilibrium statistical physics and its ruling principles. In this respect both the devices that are pushing conventional CMOS technology towards the final frontiers of Moores law and the upcoming set of alternative, novel nanostructures grounded on entirely new concepts and working principles, provide an almost unlimited playground for assessing physical models and numerical techniques emerging from classical and quantum mechanical non-equilibrium theory. In this paper we revisit the Boltzmann as well as the WignerBoltzmann equation which offers a valuable platform to study transport of charge carriers taking part in drive currents. We focus on a numerical procedure that regained attention recently as an alternative tool to solve the time-dependent Boltzmann equation for inhomogeneous systems, such as the channel regions of field-effect transistors, and we discuss its extension to the WignerBoltzmann equation. Furthermore, we pay attention to the calculation of tunneling leakage currents. The latter typically occurs in nano-scaled transistors when part of the carrier distribution sustaining the drive current is found to tunnel into the gate due the presence of an ultra-thin insulating barrier separating the gate from the channel region. In particular, we discuss the paradox related to the very existence of leakage currents established by electrons occupying quasi-bound states, while the (real) wave functions of the latter cannot carry net currents. Finally, we describe a simple model to resolve the paradox as well as to estimate gate currents provided the local carrier generation rates largely exceed the tunneling rates.
Address
Corporate Author Thesis
Publisher Place of Publication S.l. Editor
Language Wos 000208236100009 Publication Date 2009-09-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1569-8025;1572-8137; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.526 Times cited 4 Open Access
Notes Approved Most recent IF: 1.526; 2009 IF: NA
Call Number UA @ lucian @ c:irua:89503 Serial 2110
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Author Magnus, W.; Brosens, F.; Sorée, B.
Title Time dependent transport in 1D micro- and nanostructures: solving the Boltzmann and Wigner-Boltzmann equations Type A1 Journal article
Year 2009 Publication Journal of physics : conference series Abbreviated Journal
Volume 193 Issue 1 Pages 012004,1-012004,4
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Abstract For many decades the Boltzmann distribution function has been used to calculate the non-equilibrium properties of mobile particles undergoing the combined action of various scattering mechanisms and externally applied force fields. When the latter give rise to the occurrence of inhomogeneous potential profiles across the region through which the particles are moving, the numerical solution of the Boltzmann equation becomes a highly complicated task. In this work we highlight a particular algorithm that can be used to solve the time dependent Boltzmann equation as well as its quantum mechanical extension, the WignerBoltzmann equation. As an illustration, we show the calculated distribution function describing electrons propagating under the action of both a uniform and a pronouncedly non-uniform electric field.
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Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos 000277100400004 Publication Date 2009-11-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1742-6596; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 2 Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:82861 Serial 3667
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Author Ariskin, D.A.; Schweigert, I.V.; Alexandrov, A.L.; Bogaerts, A.; Peeters, F.M.
Title Modeling of chemical processes in the low pressure capacitive radio frequency discharges in a mixture of Ar/C2H2 Type A1 Journal article
Year 2009 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 105 Issue 6 Pages 063305,1-063305,9
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
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.
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Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000264774000059 Publication Date 2009-03-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.068 Times cited 21 Open Access
Notes Approved Most recent IF: 2.068; 2009 IF: 2.072
Call Number UA @ lucian @ c:irua:74496 Serial 2121
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Author de Backer, J.W.; Vos, W.G.; Burnell, P.; Verhulst, S.L.; Salmon, P.; de Clerck, N.; de Backer, W.
Title Study of the variability in upper and lower airway morphology in Sprague-Dawley rats using modern micro-CT scan-based segmentation techniques Type A1 Journal article
Year 2009 Publication The anatomical record: advances in integrative anatomy and evolutionary biology Abbreviated Journal Anat Rec
Volume 292 Issue 5 Pages 720-727
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT); Laboratory Experimental Medicine and Pediatrics (LEMP)
Abstract Animal models are being used extensively in pre-clinical and safety assessment studies to assess the effectiveness and safety of new chemical entities and delivery systems. Although never entirely replacing the need for animal testing, the use of computer simulations could eventually reduce the amount of animals needed for research purposes and refine the data acquired from the animal studies. Computational fluid dynamics is a powerful tool that makes it possible to simulate flow and particle behavior in animal or patient-specific respiratory models, for purposes of inhaled delivery. This tool requires an accurate representation of the respiratory system, respiration and dose delivery attributes. The aim of this study is to develop a representative airway model of the Sprague-Dawley rat using static and dynamic micro-CT scans. The entire respiratory tract was modeled, from the snout and nares down to the central airways at the point where no distinction could be made between intraluminal air and the surrounding tissue. For the selection of the representative model, variables such as upper airway movement, segmentation length, airway volume and size are taken into account. Dynamic scans of the nostril region were used to illustrate the characteristic morphology of this region in anaesthetized animals. It could be concluded from this study that it was possible to construct a highly detailed representative model of a Sprague-Dawley rat based on imaging modalities such as micro-CT scans
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000265766000010 Publication Date 2009-03-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-8486;1932-8494; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.431 Times cited 16 Open Access
Notes Approved Most recent IF: 1.431; 2009 IF: 1.490
Call Number UA @ lucian @ c:irua:76455 Serial 3342
Permanent link to this record
 
 
Author Croitoru, M.D.; Shanenko, A.A.; Peeters, F.M.
Title Superconducting nanowires: quantum-confinement effect on the critical magnetic field and supercurrent Type A1 Journal article
Year 2009 Publication 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 Abbreviated Journal Int J Mod Phys B
Volume 23 Issue 20-21 Pages 4257-4268
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT)
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.
Address
Corporate Author Thesis
Publisher World scientific Place of Publication Singapore Editor
Language Wos 000274525500026 Publication Date 2009-09-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0217-9792;1793-6578; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 0.736 Times cited 1 Open Access
Notes Approved Most recent IF: 0.736; 2009 IF: 0.408
Call Number UA @ lucian @ c:irua:95673 Serial 3362
Permanent link to this record
 
 
Author Leenaerts, O.; Partoens, B.; Peeters, F.M.
Title Adsorption of small molecules on graphene Type A1 Journal article
Year 2009 Publication Microelectronics journal Abbreviated Journal Microelectron J
Volume 40 Issue 4/5 Pages 860-862
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract We investigate the adsorption process of small molecules on graphene through first-principles calculations and show the presence of two main charge transfer mechanisms. Which mechanism is the dominant one depends on the magnetic properties of the adsorbing molecules. We explain these mechanisms through the density of states of the system and the molecular orbitals of the adsorbates, and demonstrate the possible difficulties in calculating the charge transfer from first principles between a graphene sheet and a molecule. Our results are in good agreement with experiment.
Address
Corporate Author Thesis
Publisher Place of Publication Luton Editor
Language Wos 000265870200058 Publication Date 2008-12-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0026-2692; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.163 Times cited 116 Open Access
Notes Approved Most recent IF: 1.163; 2009 IF: 0.778
Call Number UA @ lucian @ c:irua:77030 Serial 65
Permanent link to this record
 
 
Author Matulis, A.; Peeters, F.M.
Title Analogy between one-dimensional chain models and graphene Type A1 Journal article
Year 2009 Publication American journal of physics Abbreviated Journal Am J Phys
Volume 77 Issue 7 Pages 595-601
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract The electron and hole spectrum in single and bilayer graphene is derived from known one-dimensional models, and the relation between the spectrum and symmetry of the lattice is shown.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000266976000003 Publication Date 2009-06-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0002-9505; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.069 Times cited 11 Open Access
Notes Approved Most recent IF: 1.069; 2009 IF: 0.779
Call Number UA @ lucian @ c:irua:77381 Serial 97
Permanent link to this record
 
 
Author Masir, M.R.; Vasilopoulos, P.; Matulis, A.; Peeters, F.M.
Title Angular confinement and direction-dependent transmission in graphene nanostructures with magnetic barriers Type A1 Journal article
Year 2009 Publication AIP conference proceedings Abbreviated Journal
Volume 1199 Issue Pages 363-364
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract We evaluate the transmission through magnetic barriers in graphene-based nanostructures. Several particular cases are considered: a magnetic step, single and double barriers, delta -function barriers as well as barrier structures with inhomogeneous magnetic field profiles but with average magnetic field equal to zero. The transmission exhibits a strong dependence on the direction of the incident wave vector. In general the resonant structure of the transmission is significantly more pronounced for (Dirac) electrons with linear spectrum compared to that for electrons with a parabolic one.
Address
Corporate Author Thesis
Publisher Place of Publication New York Editor
Language Wos 000281590800171 Publication Date 2010-01-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:84892 Serial 115
Permanent link to this record
 
 
Author Castelano, L.K.; Hai, G.Q.; Partoens, B.; Peeters, F.M.
Title Artificial molecular quantum rings under magnetic field influence Type A1 Journal article
Year 2009 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 106 Issue 7 Pages 073702,1-073702,8
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract The ground states of a few electrons confined in two vertically coupled quantum rings in the presence of an external magnetic field are studied systematically within the current spin-density functional theory. Electron-electron interactions combined with inter-ring tunneling affect the electronic structure and the persistent current. For small values of the external magnetic field, we recover the zero magnetic field molecular quantum ring ground state configurations. Increasing the magnetic field many angular momentum, spin, and isospin transitions are predicted to occur in the ground state. We show that these transitions follow certain rules, which are governed by the parity of the number of electrons, the single-particle picture, Hunds rules, and many-body effects.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000270915600047 Publication Date 2009-10-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.068 Times cited 5 Open Access
Notes Approved Most recent IF: 2.068; 2009 IF: 2.072
Call Number UA @ lucian @ c:irua:86926 Serial 155
Permanent link to this record
 
 
Author Pourghaderi, M.A.; Magnus, W.; Sorée, B.; Meuris, M.; de Meyer, K.; Heyns, M.
Title Ballistic current in metal-oxide-semiconductor field-effect transistors: the role of device topology Type A1 Journal article
Year 2009 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 106 Issue 5 Pages 053702,1-053702,8
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract In this study we investigate the effect of device topology on the ballistic current in n-channel metal-oxide-semiconductor field-effect transistors. Comparison of the nanoscale planar and double-gate devices reveals that, down to a certain thickness of the double gate film, the ballistic current flowing in the double gate device is twice as large compared to its planar counterpart. On the other hand, further thinning of the film beyond this threshold is found to change noticeably the confinement and transport characteristics, which are strongly depending on the film material and the surface orientation. For double gate Ge and Si devices there exists a critical film thickness below which the transverse gate field is no longer effectively screened by the inversion layer electron gas and mutual inversion of the two gates is turned on. In the case of GaAs and other similar IIIV compounds, a decrease in the film thickness may drastically change the occupation of the L-valleys and therefore amend the transport properties. The simulation results show that, in both cases, the ballistic current and the transconductance are considerably enhanced.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000269850300052 Publication Date 2009-09-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.068 Times cited 3 Open Access
Notes Approved Most recent IF: 2.068; 2009 IF: 2.072
Call Number UA @ lucian @ c:irua:79744 Serial 214
Permanent link to this record
 
 
Author Barbier, M.; Vasilopoulos, P.; Peeters, F.M.; Pereira, J.M.
Title Band structure, density of states, and transmission in graphene bilayer superlattices Type A1 Journal article
Year 2009 Publication AIP conference proceedings Abbreviated Journal
Volume 1199 Issue Pages 547-548
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract The energy spectrum and density of states of graphene bilayer superlattices (SLs) are evaluated. We take into account doping and/or gating of the layers as well as tunnel coupling between them. In addition, we evaluate the transmission through such SLs and through single or double barriers. The transmission exhibits a strong dependence on the direction of the incident wave vector.
Address
Corporate Author Thesis
Publisher Place of Publication New York Editor
Language Wos 000281590800258 Publication Date 2010-01-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:84893 Serial 217
Permanent link to this record
 
 
Author Barbier, M.; Vasilopoulos, P.; Peeters, F.M.; Pereira, J.M.
Title Bilayer graphene with single and multiple electrostatic barriers: band structure and transmission Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 79 Issue 15 Pages 155402,1-155402,8
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract We evaluate the electronic transmission and conductance in bilayer graphene through a finite number of potential barriers. Further, we evaluate the dispersion relation in a bilayer graphene superlattice with a periodic potential applied to both layers. As a model we use the tight-binding Hamiltonian in the continuum approximation. For zero bias the dispersion relation shows a finite gap for carriers with zero momentum in the direction parallel to the barriers. This is in contrast to single-layer graphene where no such gap was found. A gap also appears for a finite bias. Numerical results for the energy spectrum, conductance, and the density of states are presented and contrasted with those pertaining to single-layer graphene.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000265944200091 Publication Date 2009-04-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 74 Open Access
Notes Approved Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:77025 Serial 235
Permanent link to this record
 
 
Author Payette, C.; Yu, G.; Gupta, J.A.; Austing, D.G.; Nair, S.V.; Partoens, B.; Amaha, S.; Tarucha, S.
Title Coherent three-level mixing in an electronic quantum dot Type A1 Journal article
Year 2009 Publication Physical review letters Abbreviated Journal Phys Rev Lett
Volume 102 Issue 2 Pages 026808,1-026808,4
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract We observe magnetic-field-induced level mixing and quantum superposition phenomena between three approaching single-particle states in a quantum dot probed via the ground state of an adjacent quantum dot by single-electron resonant tunneling. The mixing is attributed to anisotropy and anharmonicity in realistic dot confining potentials. The pronounced anticrossing and transfer of strengths (both enhancement and suppression) between resonances can be understood with a simple coherent level mixing model. Superposition can lead to the formation of a dark state by complete cancellation of an otherwise strong resonance, an effect resembling coherent population trapping in a three-level-system of quantum and atom optics.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000262535900060 Publication Date 2009-01-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007;1079-7114; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.462 Times cited 26 Open Access
Notes Approved Most recent IF: 8.462; 2009 IF: 7.328
Call Number UA @ lucian @ c:irua:76019 Serial 382
Permanent link to this record
 
 
Author Pogosov, W.V.; Misko, V.R.; Zhao, H.J.; Peeters, F.M.
Title Collective vortex phases in periodic plus random pinning potential Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 79 Issue 1 Pages 014504,1-014504,12
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract We study theoretically the simultaneous effect of regular and random pinning potentials on the vortex lattice structure at filling factor of 1. This structure is determined by a competition between the square symmetry of regular pinning array, by the intervortex interaction favoring a triangular symmetry, and by the randomness trying to depin vortices from their regular positions. Both analytical and molecular-dynamics approaches are used. We construct a phase diagram of the system in the plane of regular and random pinning strengths and determine typical vortex lattice defects appearing in the system due to the disorder. We find that the total disordering of the vortex lattice can occur either in one step or in two steps. For instance, in the limit of weak pinning, a square lattice of pinned vortices is destroyed in two steps. First, elastic chains of depinned vortices appear in the film; but the vortex lattice as a whole remains still pinned by the underlying square array of regular pinning sites. These chains are composed into fractal-like structures. In a second step, domains of totally depinned vortices are generated and the vortex lattice depins from regular array.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000262977900092 Publication Date 2009-01-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 14 Open Access
Notes Approved Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:75982 Serial 386
Permanent link to this record
 
 
Author Berdiyorov, G.R.; Milošević, M.V.; Peeters, F.M.
Title Composite vortex ordering in superconducting films with arrays of blind holes Type A1 Journal article
Year 2009 Publication New journal of physics Abbreviated Journal New J Phys
Volume 11 Issue Pages 013025,1-013025,20
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract The pinning properties of a superconducting thin film with a square array of blind holes are studied using the nonlinear GinzburgLandau theory. Although blind holes provide a weaker pinning potential than holes (also called antidots), several novel vortex structures are predicted for different size and thickness of the blind holes. Orientational dimer and trimer vortex states as well as concentric vortex shells can nucleate in the blind holes. In addition, we predict the stabilization of giant vortices that may be located both in the pinning centers and/or at the interstitial sites, as well as the combination of giant vortices with sets of individual vortices. For large blind holes, local vortex shell structures inside the blind holes may transfer their symmetry to interstitial vortices as well. The subtle interplay of shell formation and traditional Abrikosov vortex lattices inside the blind holes is also studied for different numbers of trapped vortices.
Address
Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos 000262932600002 Publication Date 2009-01-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1367-2630; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.786 Times cited 33 Open Access
Notes Approved Most recent IF: 3.786; 2009 IF: 3.312
Call Number UA @ lucian @ c:irua:75987 Serial 441
Permanent link to this record
 
 
Author Berdiyorov, G.R.; Hernandez, A.D.; Peeters, F.M.
Title Confinement effects on intermediate-state flux patterns in mesoscopic type-I superconductors Type A1 Journal article
Year 2009 Publication Physical review letters Abbreviated Journal Phys Rev Lett
Volume 103 Issue 26 Pages 267002,1-267002,4
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract Intermediate-state flux structures in mesoscopic type-I superconductors are studied within the Ginzburg-Landau theory. In addition to well-established tubular and laminar structures, the strong confinement leads to the formation of (i) a phase of singly quantized vortices, which is typical for type-II superconductors and (ii) a ring of a normal domain at equilibrium. The stability region and the formation process of these intermediate-state structures are strongly influenced by the geometry of the sample.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000273232200042 Publication Date 2009-12-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007;1079-7114; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.462 Times cited 28 Open Access
Notes Approved Most recent IF: 8.462; 2009 IF: 7.328
Call Number UA @ lucian @ c:irua:80574 Serial 488
Permanent link to this record
 
 
Author Connolly, M.R.; Milošević, M.V.; Bending, S.J.; Clem, J.R.; Tamegai, T.
Title Continuum vs. discrete flux behaviour in large mesoscopic Bi2Sr2CaCu2O8+\delta disks Type A1 Journal article
Year 2009 Publication Europhysics letters Abbreviated Journal Epl-Europhys Lett
Volume 85 Issue 1 Pages 17008,1-17008,6
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract Scanning Hall probe and local Hall magnetometry measurements have been used to investigate flux distributions in large mesoscopic superconducting disks with sizes that lie near the crossover between the bulk and mesoscopic vortex regimes. Results obtained by directly mapping the magnetic induction profiles of the disks at different applied fields can be quite successfully fitted to analytic models which assume a continuous distribution of flux in the sample. At low fields, however, we do observe clear signatures of the underlying discrete vortex structure and can resolve the characteristic mesoscopic compression of vortex clusters in increasing magnetic fields. Even at higher fields, where single-vortex resolution is lost, we are still able to track configurational changes in the vortex patterns, since competing vortex orders impose unmistakable signatures on “local” magnetisation curves as a function of the applied field. Our observations are in excellent agreement with molecular-dynamics numerical simulations which lead us to a natural definition of the lengthscale for the crossover between discrete and continuum behaviours in our system.
Address
Corporate Author Thesis
Publisher Place of Publication Paris Editor
Language Wos 000263692500029 Publication Date 2009-01-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0295-5075;1286-4854; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.957 Times cited 17 Open Access
Notes Approved Most recent IF: 1.957; 2009 IF: 2.893
Call Number UA @ lucian @ c:irua:76306 Serial 495
Permanent link to this record
 
 
Author Kerner, C.; Hackens, B.; Golubović, D.S.; Poli, S.; Faniel, S.; Magnus, W.; Schoenmaker, W.; Bayot, V.; Maes, H.
Title Control and readout of current-induced magnetic flux quantization in a superconducting transformer Type A1 Journal article
Year 2009 Publication Superconductor science and technology Abbreviated Journal Supercond Sci Tech
Volume 22 Issue 2 Pages 025001,1-025001,4
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract We demonstrate a simple and robust method for inducing and detecting changes of magnetic flux quantization in the absence of an externally applied magnetic field. In our device, an isolated ring is interconnected with two access loops via permalloy cores, forming a superconducting transformer. By applying and tuning a direct current at the first access loop, the number of flux quanta trapped in the isolated ring is modified without the aid of an external field. The flux state of the isolated ring is simply detected by recording the evolution of the critical current of the second access loop.
Address
Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos 000262786000003 Publication Date 2008-12-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-2048;1361-6668; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.878 Times cited 2 Open Access
Notes Approved Most recent IF: 2.878; 2009 IF: 2.694
Call Number UA @ lucian @ c:irua:76001 Serial 497
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Author Wang, M.; Chang, K.; Wang, L.G.; Dai, N.; Peeters, F.M.
Title Crystallographic plane tuning of charge and spin transport in semiconductor quantum wires Type A1 Journal article
Year 2009 Publication Nanotechnology Abbreviated Journal Nanotechnology
Volume 20 Issue 36 Pages 365202,1-365202,8
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract We investigate theoretically the charge and spin transport in quantum wires grown along different crystallographic planes in the presence of the Rashba spinorbit interaction (RSOI) and the Dresselhaus spinorbit interaction (DSOI). We find that changing the crystallographic planes leads to a variation of the anisotropy of the conductance due to a different interplay between the RSOI and DSOI, since the DSOI is induced by bulk inversion asymmetry, which is determined by crystallographic plane. This interplay depends sensitively on the crystallographic planes, and consequently leads to the anisotropic charge and spin transport in quantum wires embedded in different crystallographic planes.
Address
Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos 000269077000003 Publication Date 2009-08-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0957-4484;1361-6528; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.44 Times cited 14 Open Access
Notes Approved Most recent IF: 3.44; 2009 IF: 3.137
Call Number UA @ lucian @ c:irua:78933 Serial 588
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Author Xu, W.; Peeters, F.M.; Lu, T.C.
Title Dependence of resistivity on electron density and temperature in graphene Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 79 Issue 7 Pages 073403,1-073403,4
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract On the basis of the momentum-balance equation derived from the Boltzmann equation in which electron interactions with impurities and acoustic and optic phonons are included, we examine the dependence of the resistivity in graphene on temperature and electron density. Simple analytical expressions for the different contributions to the resistivity are obtained. Our results reproduce recent experimental findings and we are able to understand the different temperature dependence of the resistivity for low and high density samples.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000263815800013 Publication Date 2009-02-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 31 Open Access
Notes Approved Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:76222 Serial 642
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Author Li, B.; Partoens, B.; Peeters, F.M.; Magnus, W.
Title Dielectric mismatch effect on coupled impurity states in a freestanding nanowire Type A1 Journal article
Year 2009 Publication Microelectronics journal Abbreviated Journal Microelectron J
Volume 40 Issue 3 Pages 446-448
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract We studied the coupled impurity states in a freestanding semiconductor nanowire (NW), within the effective mass approximation and including the effect of the dielectric mismatch, by using finite element method. Bonding and anti-bonding states are found and their energies converge with increasing distance di between the two impurities. The dependence of the binding energy on the wire radius R and the distance di between the two impurities is investigated, and we compare it with the result of a freestanding NW that contains a single impurity.
Address
Corporate Author Thesis
Publisher Place of Publication Luton Editor
Language Wos 000264694700017 Publication Date 2008-07-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0026-2692; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.163 Times cited 4 Open Access
Notes Approved Most recent IF: 1.163; 2009 IF: 0.778
Call Number UA @ lucian @ c:irua:76410 Serial 690
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Author Li, B.; Partoens, B.; Peeters, F.M.; Magnus, W.
Title Dielectric mismatch effect on coupled shallow impurity states in a semiconductor nanowire Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 79 Issue 8 Pages 085306,1-085306,7
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract Coupled shallow impurity states in a freestanding semiconductor nanowire and in a semiconductor nanowire surrounded by a metallic gate are studied within the effective-mass approximation. Bonding and antibonding states are found due to the coupling of the two impurities, and their energy converges with increasing distance di between the two impurities. The dependences of the binding energy on the wire radius R, the distance di between the two impurities, and the impurity radial position in the nanowire are examined.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000263816000051 Publication Date 2009-02-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 11 Open Access
Notes Approved Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:76223 Serial 691
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Author Barbier, M.; Vasilopoulos, P.; Peeters, F.M.
Title Dirac electrons in a Kronig-Penney potential: dispersion relation and transmission periodic in the strength of the barriers Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 80 Issue 20 Pages 205415,1-205415,5
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract The transmission T and conductance G through one or multiple one-dimensional, ä-function barriers of two-dimensional fermions with a linear energy spectrum are studied. T and G are periodic functions of the strength P of the ä-function barrier V(x,y)/ℏvF=Pä(x). The dispersion relation of a Kronig-Penney (KP) model of a superlattice is also a periodic function of P and causes collimation of an incident electron beam for P=2ðn and n integer. For a KP superlattice with alternating sign of the height of the barriers the Dirac point becomes a Dirac line for P=(n+1/2)ð.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000272311400101 Publication Date 2009-12-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 93 Open Access
Notes Approved Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:80316 Serial 707
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Author Li, J.; Chang, K.; Peeters, F.M.
Title Dyakonov-Perel spin relaxation in InSb/AlxIn1-xSb quantum wells Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 80 Issue 15 Pages 153307,1-153307,4
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract We investigate theoretically the Dyakonov-Perel spin relaxation time by solving the eight-band Kane model and Poisson equation self-consistently. Our results show distinct behavior with the single-band model due to the anomalous spin-orbit interactions in narrow band-gap semiconductors, and agree well with the experiment values reported in recent experiment [K. L. Litvinenko et al., New J. Phys. 8, 49 (2006)]. We find a strong resonant enhancement of the spin relaxation time appears for spin align along [11̅ 0] at a certain electron density at 4 K. This resonant peak is smeared out with increasing the temperature.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000271352000015 Publication Date 2009-11-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 6 Open Access
Notes Approved Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:79996 Serial 760
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Author Tkachenko, D.V.; Misko, V.R.; Peeters, F.M.
Title Dynamics of colloids in a narrow channel driven by a nonuniform force Type A1 Journal article
Year 2009 Publication Physical review : E : statistical physics, plasmas, fluids, and related interdisciplinary topics Abbreviated Journal Phys Rev E
Volume 80 Issue 5 Pages 051401,1-051401,10
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using Brownian dynamics simulations, we investigate the dynamics of colloids confined in two-dimensional narrow channels driven by a nonuniform force Fdr(y). We considered linear-gradient, parabolic, and deltalike driving-force profiles. This driving force induces melting of the colloidal solid (i.e., shear-induced melting), and the colloidal motion experiences a transition from elastic to plastic regime with increasing Fdr. For intermediate Fdr (i.e., in the transition region) the response of the system, i.e., the distribution of the velocities of the colloidal chains õi(y), in general does not coincide with the profile of the driving force Fdr(y), and depends on the magnitude of Fdr, the width of the channel, and the density of colloids. For example, we show that the onset of plasticity is first observed near the boundaries while the motion in the central region is elastic. This is explained by: (i) (in)commensurability between the chains due to the larger density of colloids near the boundaries, and (ii) the gradient in Fdr. Our study provides a deeper understanding of the dynamics of colloids in channels and could be accessed in experiments on colloids (or in dusty plasma) with, e.g., asymmetric channels or in the presence of a gradient potential field.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000272309500045 Publication Date 2009-11-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1539-3755;1550-2376; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.366 Times cited 14 Open Access
Notes Approved Most recent IF: 2.366; 2009 IF: 2.400
Call Number UA @ lucian @ c:irua:80313 Serial 774
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Author Berdiyorov, G.R.; Yu, S.H.; Xiao, Z.L.; Peeters, F.M.; Hua, J.; Imre, A.; Kwok, W.K.
Title Effect of sample geometry on the phase boundary of a mesoscopic superconducting loop Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 80 Issue 6 Pages 064511,1-064511,6
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract We studied the effect of sample geometry on the evolution of the superconducting state in nanoscale Nb circular and square loops by transport measurements. A multistage resistive transition with temperature is found for both samples, which is related to the effect of contact leads made from the same superconducting material. The H-T phase diagrams close to Tc0 show clear periodic oscillations on top of a parabolic background, i.e., Little-Parks effect. However, the amplitude of the oscillations decreases faster in the circular loop compared to the one in the square sample. Numerical simulations are conducted within the nonlinear Ginzburg-Landau theory to show the effect of sample geometry on the nucleation of superconductivity in superconducting loop structures.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000269638800067 Publication Date 2009-08-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 21 Open Access
Notes Approved Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:78292 Serial 833
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Author Avetisyan, A.A.; Partoens, B.; Peeters, F.M.
Title Electric-field control of the band gap and Fermi energy in graphene multilayers by top and back gates Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 80 Issue 19 Pages 195401,1-195401,11
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract It is known that a perpendicular electric field applied to multilayers of graphene modifies the electronic structure near the K point and may induce an energy gap in the electronic spectrum which is tunable by the gate voltage. Here we consider a system of graphene multilayers in the presence of a positively charged top and a negatively charged back gate to control independently the density of electrons on the graphene layers and the Fermi energy of the system. The band structure of three- and four-layer graphene systems in the presence of the top and back gates is obtained using a tight-binding approach. A self-consistent Hartree approximation is used to calculate the induced charges on the different graphene layers. We predict that for opposite and equal charges on the top and bottom layers an energy gap is opened at the Fermi level. For an even number of layers this gap is larger than in the case of an odd number of graphene layers. We find that the circular asymmetry of the spectrum, which is a consequence of the trigonal warping, changes the size of the induced electronic gap, even when the total density of the induced electrons on the graphene layers is low.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000272311000087 Publication Date 2009-11-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 106 Open Access
Notes Approved Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:80315 Serial 883
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Author Avetisyan, A.A.; Partoens, B.; Peeters, F.M.
Title Electric field tuning of the band gap in graphene multilayers Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 79 Issue 3 Pages 035421,1-035421,7
Keywords (down) A1 Journal article; Condensed Matter Theory (CMT)
Abstract A perpendicular electric field applied to multilayers of graphene modifies the electronic structure near the K point and may induce an energy gap in the electronic spectrum. This gap is tunable by the gate voltage and its size depends on the number of layers. We use a tight-binding approach to calculate the band structure and include a self-consistent calculation in order to obtain the density of charge carriers. Results are presented for systems consisting of three and four layers of graphene. The effect of the circular asymmetry of the band structure on the gap is critically examined.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000262978200119 Publication Date 2009-01-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 106 Open Access
Notes Approved Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:75984 Serial 887
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