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Author Moors, K.; Sorée, B.; Magnus, W.
Title Validity criteria for Fermi's golden rule scattering rates applied to metallic nanowires Type A1 Journal article
Year 2016 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat
Volume 28 Issue 28 Pages (up) 365302
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Fermi's golden rule underpins the investigation of mobile carriers propagating through various solids, being a standard tool to calculate their scattering rates. As such, it provides a perturbative estimate under the implicit assumption that the effect of the interaction Hamiltonian which causes the scattering events is sufficiently small. To check the validity of this assumption, we present a general framework to derive simple validity criteria in order to assess whether the scattering rates can be trusted for the system under consideration, given its statistical properties such as average size, electron density, impurity density et cetera. We derive concrete validity criteria for metallic nanowires with conduction electrons populating a single parabolic band subjected to different elastic scattering mechanisms: impurities, grain boundaries and surface roughness.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000380754400013 Publication Date 2016-07-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.649 Times cited 2 Open Access
Notes ; ; Approved Most recent IF: 2.649
Call Number UA @ lucian @ c:irua:135011 Serial 4274
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Author Wang, J.; Shin, Y.; Gauquelin, N.; Yang, Y.; Lee, C.; Jannis, D.; Verbeeck, J.; Rondinelli, J.M.; May, S.J.
Title Physical properties of epitaxial SrMnO2.5−δFγoxyfluoride films Type A1 Journal article
Year 2019 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat
Volume 31 Issue 36 Pages (up) 365602
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Recently, topotactic fluorination has become an alternative way of doping epitaxial perovskite oxides through anion substitution to engineer their electronic properties instead of the more commonly used cation substitution. In this work, epitaxial oxyfluoride SrMnO2.5−δ F γ films were synthesized via topotactic fluorination of SrMnO2.5 films using polytetrafluoroethylene as the fluorine source. Oxidized SrMnO3 films were also prepared for comparison with the fluorinated samples. The F content, probed by x-ray photoemission spectroscopy, was systematically controlled by adjusting fluorination conditions. Electronic transport measurements reveal that increased F content (up to γ  =  0.14) systematically increases the electrical resistivity, despite the nominal electron-doping induced by F substitution for O in these films. In contrast, oxidized SrMnO3 exhibits a decreased resistivity and conduction activation energy. A blue-shift of optical absorption features occurs with increasing F content. Density functional theory calculations indicate that F acts as a scattering center for electronic transport, controls the observed weak ferromagnetic behavior of the films, and reduces the inter-band optical transitions in the manganite films. These results stand in contrast to bulk electron-doped La1−x Ce x MnO3, illustrating how aliovalent anionic substitutions can yield physical behavior distinct from A-site substituted perovskites with the same nominal B-site oxidation states.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000472232000002 Publication Date 2019-09-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.649 Times cited 5 Open Access
Notes Work at Drexel was supported by the National Science Foundation (NSF), grant number CMMI-1562223. Thin film synthesis utilized deposition instrumentation acquired through an Army Research Office DURIP grant (W911NF-14-1-0493). Y.S and J.M.R. were supported by NSF (Grant No. DMR-1454688). Calculations were performed using the QUEST HPC Facility at Northwestern, the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by NSF Grant No. ACI-1053575, and the Center for Nanoscale Materials (Carbon Cluster). Use of the Center for Nanoscale Materials, an Office of Science user facility, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. J.V. and N. G. acknowledge funding from a GOA project “Solarpaint” of the University of Antwerp. D.J. acknowledges funding from FWO project G093417N from the Flemish fund for scientific research. Approved Most recent IF: 2.649
Call Number EMAT @ emat @UA @ admin @ c:irua:161174 Serial 5293
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Author Sena, S.H.R.; Pereira, J.M.; Farias, G.A.; Peeters, F.M.; Costa Filho, R.N.
Title The electronic properties of graphene and graphene ribbons under simple shear strain Type A1 Journal article
Year 2012 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat
Volume 24 Issue 37 Pages (up) 375301
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract A tight-binding model is used to study the energy band of graphene and graphene ribbon under simple shear strain. The ribbon consists of lines of carbon atoms in an armchair or zigzag orientation where a simple shear strain is applied in the x-direction keeping the atomic distances in the y-direction unchanged. Such modification in the lattice gives an energy band that differs in several aspects from the one without any shear and with pure shear. The changes in the spectrum depend on the line displacement of the ribbon, and also on the modified hopping parameter. It is also shown that this simple shear strain tunes the electronic properties of both graphene and graphene ribbon, opening and closing energy gaps for different displacements of the system. The modified density of states is also shown.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000308202700011 Publication Date 2012-08-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984;1361-648X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.649 Times cited 15 Open Access
Notes ; This work was supported by CNPq (RNCF), the National Council for the Improvement of Higher Education (CAPES), the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and the bilateral program between Flanders and Brazil. ; Approved Most recent IF: 2.649; 2012 IF: 2.355
Call Number UA @ lucian @ c:irua:101838 Serial 1000
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Author Abdullah, H.M.; Bahlouli, H.; Peeters, F.M.; Van Duppen, B.
Title Confined states in graphene quantum blisters Type A1 Journal article
Year 2018 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat
Volume 30 Issue 38 Pages (up) 385301
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Bilayer graphene samples may exhibit regions where the two layers are locally delaminated forming a so-called quanttun blister in the graphene sheet. Electron and hole states can be confined in this graphene quantum blisters (GQB) by applying a global electrostatic bias. We scrutinize the electronic properties of these confined states under the variation of interlayer bias, coupling, and blister's size. The spectra display strong anti-crossings due to the coupling of the confined states on upper and lower layers inside the blister. These spectra are layer localized where the respective confined states reside on either layer or equally distributed. For finite angular momentum, this layer localization can be at the edge of the blister and corresponds to degenerate modes of opposite momenta. Furthermore, the energy levels in GQB exhibit electron-hole symmetry that is sensitive to the electrostatic bias. Finally, we demonstrate that confinement in GQB persists even in the presence of a variation in the interlayer coupling.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000443135000001 Publication Date 2018-08-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.649 Times cited 6 Open Access
Notes ; HMA and HB acknowledge the Saudi Center for Theoretical Physics (SCTP) for their generous support and the support of KFUPM under physics research group projects RG1502-1 and RG1502-2. This work is supported by the Flemish Science Foundation (FWO-Vl) by a post-doctoral fellowship (BVD). ; Approved Most recent IF: 2.649
Call Number UA @ lucian @ c:irua:153620UA @ admin @ c:irua:153620 Serial 5086
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Author Nowak, M.P.; Szafran, B.; Peeters, F.M.
Title Manipulation of two-electron states by the electric field in stacked self-assembled dots Type A1 Journal article
Year 2008 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat
Volume 20 Issue 39 Pages (up) 395225,1-395225,14
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract A pair of electrons in vertically stacked self-assembled quantum dots is studied and the singlettriplet energy splitting is calculated in an external electric field using the configuration-interaction method. We show that for double quantum dots the dependence of the singlet energy levels on the electric field involves multiple avoided crossings of three energy levels. The exchange interaction, i.e., the energy difference of the lowest triplet and lowest singlet states, can be tuned by an electric field in a wide range of several tens of meV. For electric fields exceeding a threshold value the exchange interaction becomes a linear function of the field when the two electrons in the singlet state start to occupy the same dot. We also consider non-symmetric confinement, non-perfectly aligned dots, in horizontal as well as vertical field orientation. In a stack of three vertically coupled dots the depth of the confinement in the central dot can be used to enhance the exchange interaction. For a deeper central dot the dependence of the exchange interaction on the electric field is anomalousit initially decreases when the field is applied in both directions parallel and antiparallel to the axis of the stack. Such a behavior is never observed for a pair of quantum dots.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000259034200032 Publication Date 2008-09-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984;1361-648X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.649 Times cited 5 Open Access
Notes Approved Most recent IF: 2.649; 2008 IF: 1.900
Call Number UA @ lucian @ c:irua:76592 Serial 1940
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Author Dabaghmanesh, S.; Saniz, R.; Amini, M.N.; Lamoen, D.; Partoens, B.
Title Perovskite transparent conducting oxides : an ab initio study Type A1 Journal article
Year 2013 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat
Volume 25 Issue 41 Pages (up) 415503
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract We present an ab initio study of the electronic structure and of the formation energies of various point defects in BaSnO3 and SrGeO3. We show that La and Y impurities substituting Ba or Sr are shallow donors with a preferred 1 + charge state. These defects have a low formation energy within all the suitable equilibrium growth conditions considered. Oxygen vacancies behave as shallow donors as well, preferring the 2 + charge state. Their formation energies, however, are higher in most growth conditions, indicating a limited contribution to conductivity. The calculated electron effective mass in BaSnO3, with a value of 0.21 me, and the very high mobility reported recently in La-doped BaSnO3 single-crystals, suggest that remarkably low scattering rates can be achieved in the latter. In the case of SrGeO3, our results point to carrier density and mobility values in the low range for typical polycrystalline TCOs, in line with experiment.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000324920400011 Publication Date 2013-09-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984;1361-648X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.649 Times cited 17 Open Access
Notes FWO;Hercules Approved Most recent IF: 2.649; 2013 IF: 2.223
Call Number UA @ lucian @ c:irua:110495 Serial 2574
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Author Abdullah, H.M.; Van Duppen, B.; Zarenia, M.; Bahlouli, H.; Peeters, F.M.
Title Quantum transport across van der Waals domain walls in bilayer graphene Type A1 Journal article
Year 2017 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat
Volume 29 Issue 42 Pages (up) 425303
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Bilayer graphene can exhibit deformations such that the two graphene sheets are locally detached from each other resulting in a structure consisting of domains with different van der Waals inter-layer coupling. Here we investigate how the presence of these domains affects the transport properties of bilayer graphene. We derive analytical expressions for the transmission probability, and the corresponding conductance, across walls separating different inter-layer coupling domains. We find that the transmission can exhibit a valley-dependent layer asymmetry and that the domain walls have a considerable effect on the chiral tunnelling properties of the charge carriers. We show that transport measurements allow one to obtain the strength with which the two layers are coupled. We perform numerical calculations for systems with two domain walls and find that the availability of multiple transport channels in bilayer graphene significantly modifies the conductance dependence on inter-layer potential asymmetry.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000410958400001 Publication Date 2017-07-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.649 Times cited 15 Open Access
Notes ; HMA and HB acknowledge the Saudi Center for Theoretical Physics (SCTP) for their generous support and the support of KFUPM under physics research group projects RG1502-1 and RG1502-2. This work is supported by the Flemish Science Foundation (FWO-VI) by a post-doctoral fellowship (BVD). ; Approved Most recent IF: 2.649
Call Number UA @ lucian @ c:irua:146664 Serial 4793
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Author Pizzochero, M.; Leenaerts, O.; Partoens, B.; Martinazzo, R.; Peeters, F.M.
Title Hydrogen adsorption on nitrogen and boron doped graphene Type A1 Journal article
Year 2015 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat
Volume 27 Issue 27 Pages (up) 425502
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Hydrogen adsorption on boron and nitrogen doped graphene is investigated in detail by means of first-principles calculations. A comprehensive study is performed of the structural, electronic, and magnetic properties of chemisorbed hydrogen atoms and atom pairs near the dopant sites. The main effect of the substitutional atoms is charge doping which is found to greatly affect the adsorption process by increasing the binding energy at the sites closest to the substitutional species. It is also found that doping does not induce magnetism despite the odd number of electrons per atom introduced by the foreign species, and that it quenches the paramagnetic response of chemisorbed H atoms on graphene. Overall, the effects are similar for B and N doping, with only minor differences in the adsorption energetics due to different sizes of the dopant atoms and the accompanying lattice distortions.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Wos 000362573500008 Publication Date 2015-10-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984;1361-648X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.649 Times cited 20 Open Access
Notes This work was supported by the Flemish Science Foundation (FWO-Vl). MP gratefully acknowledges the Condensed Matter Theory group at Universiteit Antwerpen for the hospitality during his stay. Approved Most recent IF: 2.649; 2015 IF: 2.346
Call Number c:irua:128759 Serial 3971
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Author Chen, Y.; Croitoru, M.D.; Shanenko, A.A.; Peeters, F.M.
Title Superconducting nanowires: quantum confinement and spatially dependent Hartree-Fock potential Type A1 Journal article
Year 2009 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat
Volume 21 Issue 43 Pages (up) 435701,1-435701,7
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
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.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000270642700012 Publication Date 2009-10-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984;1361-648X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.649 Times cited 12 Open Access
Notes Approved Most recent IF: 2.649; 2009 IF: 1.964
Call Number UA @ lucian @ c:irua:79162 Serial 3360
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Author Masir, M.R.; Vasilopoulos, P.; Peeters, F.M.
Title Kronig-Penney model of scalar and vector potentials in graphene Type A1 Journal article
Year 2010 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat
Volume 22 Issue 46 Pages (up) 465302,1-465302,10
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We consider a one-dimensional (1D) superlattice (SL) on graphene consisting of very high and very thin (δ-function) magnetic and potential barriers with zero average potential and zero magnetic field. We calculate the energy spectrum analytically, study it in different limiting cases, and determine the condition under which an electron beam incident on an SL is highly collimated along its direction. In the absence of the magnetic SL the collimation is very sensitive to the value of W/Ws and is optimal for W/Ws = 1, where W is the distance between the positive and negative barriers and L = W + Ws is the size of the unit cell. In the presence of only the magnetic SL the collimation decreases and the symmetry of the spectrum around ky is broken for W/Ws\neq 1 . In addition, a gap opens which depends on the strength of the magnetic field. We also investigate the effect of spatially separated potential and magnetic δ-function barriers and predict a better collimation in specific cases.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000283838800004 Publication Date 2010-11-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984;1361-648X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.649 Times cited 41 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-VI), the Belgian Science Policy (IAP), and the Canadian NSERC Grant No. OGP0121756. ; Approved Most recent IF: 2.649; 2010 IF: 2.332
Call Number UA @ lucian @ c:irua:85807 Serial 1767
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Author Petrovic, M.D.; Peeters, F.M.; Chaves, A.; Farias, G.A.
Title Conductance maps of quantum rings due to a local potential perturbation Type A1 Journal article
Year 2013 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat
Volume 25 Issue 49 Pages (up) 495301-495309
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We performed a numerical simulation of the dynamics of a Gaussian shaped wavepacket inside a small sized quantum ring, smoothly connected to two leads and exposed to a perturbing potential of a biased atomic force microscope tip. Using the Landauer formalism, we calculated conductance maps of this system in the case of single and two subband transport. We explain the main features in the conductance maps as due to the AFM tip influence on the wavepacket phase and amplitude. In the presence of an external magnetic field, the tip modifies the phi(0) periodic Aharonov-Bohm oscillation pattern into a phi(0)/2 periodic Al'tshuler-Aronov-Spivak oscillation pattern. Our results in the case of multiband transport suggest tip selectivity to higher subbands, making them more observable in the total
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000327181400002 Publication Date 2013-11-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984;1361-648X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.649 Times cited 12 Open Access
Notes ; This work was supported by the Methusalem programme of the Flemish government, the CNPq-FWO bilateral programme and PNPD and FUNCAP/PRONEX grants. ; Approved Most recent IF: 2.649; 2013 IF: 2.223
Call Number UA @ lucian @ c:irua:112694 Serial 478
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Author Silva, F.C.O.; Menezes, R.M.; Cabral, L.R.E.; de Souza Silva, C.C.
Title Formation and stability of conformal spirals in confined 2D crystals Type A1 Journal article
Year 2020 Publication Journal Of Physics-Condensed Matter Abbreviated Journal J Phys-Condens Mat
Volume 32 Issue 50 Pages (up) 505401
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We investigate the ground-state and dynamical properties of nonuniform two-dimensional (2D) clusters of long-range interacting particles. We demonstrate that, when the confining external potential is designed to produce an approximate 1/ r 2 density profile, the particles crystallize into highly ordered structures featuring spiral crystalline lines. Despite the strong inhomogeneity of the observed configurations, most of them are characterized by small density of topological defects, typical of conformal crystals, and the net topological charge induced by the simply-connected geometry of the system is concentrated near the cluster center. These crystals are shown to be robust with respect to thermal fluctuations up to a certain threshold temperature, above which the net charge is progressively redistributed from the center to the rest of the system and the topological order is lost. The crystals are also resilient to the shear stress produced by a small nonuniform azimuthal force field, rotating as a rigid body (RB). For larger forces, topological defects proliferate and the RB rotation gives place to plastic flow.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2020-08-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984 ISBN Additional Links UA library record
Impact Factor 2.7 Times cited Open Access
Notes Approved Most recent IF: 2.7; 2020 IF: 2.649
Call Number UA @ admin @ c:irua:191093 Serial 7978
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