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Author Tadić, M.; Peeters, F.M.
Title Excitonic properties of strained triple quantum-ring molecules Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 79 Issue 15 Pages 153305,1-153305,4
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The tunneling coupling in three vertically stacked (In,Ga)As/GaAs quantum rings is investigated. With increasing inter-ring separation (d), we find that the nonuniform strain results into a crossing of the lowest-energy electron states. Strain is also responsible for an increase in the ground electron energy above the level in the single quantum ring. The ground hole energy level exhibits decrease when d decreases, which is typical for antibonding states in an unstrained structure. These effects lead to a local maximum in the dependence of the ground-state exciton energy on d. Our theoretical results compare well with recent photoluminescence measurements but deviate considerably from the calculations for flat bands in quantum-ring molecules. We conclude that the nonuniform character of the strain distribution gives rise to a peculiar exciton hybridization in self-assembled quantum-ring molecules.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000265944200018 Publication Date 2009-04-21
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 8 Open Access
Notes Approved (up) Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:77024 Serial 1123
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Author Berdiyorov, G.R.; Elmurodov, A.K.; Peeters, F.M.; Vodolazov, D.Y.
Title Finite-size effect on the resistive state in a mesoscopic type-II superconducting stripe Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 79 Issue 17 Pages 174506,1-174506,6
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Within the time-dependent Ginzburg-Landau (TDGL) theory we studied the creation of phase-slip lines and the interplay with a vortex lattice in a finite-length superconducting thin stripe with finite-size normal metal leads. In zero magnetic field and with increasing transport current phase-slip lines appear across the sample leading to distinct jumps in the current-voltage characteristics. When a magnetic field is applied, the moving vortex lattice becomes rearranged by the external current and fast and slow moving vortex channels are formed. Curved vortex channels are observed near the normal contacts. We found the remarkable result that at small applied magnetic field the normal-state transition current is increased as compared to the one at zero magnetic field. This effect is more pronounced for larger values of the parameter in the TDGL formalism. This unusual field-induced increase in the critical current is a consequence of the nonuniform distribution of the current in the sample.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000266501100096 Publication Date 2009-05-05
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 36 Open Access
Notes Approved (up) Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:77398 Serial 1196
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Author Leenaerts, O.; Partoens, B.; Peeters, F.M.
Title Hydrogenation of bilayer graphene and the formation of bilayer graphane from first principles Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 80 Issue 24 Pages 245422,1-245422,6
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We performed ab initio density-functional theory calculations to investigate the process of hydrogenation of a bilayer of graphene. 50% hydrogen coverage is possible in case that the hydrogen atoms are allowed to adsorb on both sides of the bilayer. In this case interlayer chemical bonding occurs which stabilizes the structure. At maximum coverage, a bilayer of graphane is formed which has properties that are similar to those of a single layer of graphane.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000273229200126 Publication Date 2009-12-21
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 113 Open Access
Notes Approved (up) Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:80578 Serial 1535
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Author Zha, G.-Q.; Chen, Y.; Peeters, F.M.; Zhou, S.-P.
Title Impurity-induced modulations of orders in d-wave superconductors Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 80 Issue 6 Pages 064518,1-064518,5
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract By using a model Hamiltonian with competing antiferromagnetic (AFM) and d-wave superconductivity orders, the impurity-induced structures of orders in d-wave superconductors is investigated. We find that the transition between one-dimensional stripe and two-dimensional checkerboardlike modulation around a single nonmagnetic impurity can take place as the strength of the AFM interaction U or the impurity scattering strength V0 is varied. It is also found that the impurity-induced stripe can first transit to checkerboardlike modulation and then disappears with increasing the next-nearest-neighbor hopping strength |t|. Phase diagrams of V0 versus U and |t| for various modulations of the spin order are presented. In addition, the quantum interference effect on the modulations of orders due to two strong nonmagnetic impurities is briefly examined, and the checkerboardlike and quasistripe patterns can occur depending on the sites where two impurities are placed.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000269638800074 Publication Date 2009-09-01
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 3 Open Access
Notes Approved (up) Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:78293 Serial 1572
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Author Berdiyorov, G.R.; Milošević, M.V.; Peeters, F.M.
Title Kinematic vortex-antivortex lines in strongly driven superconducting stripes Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 19 Issue 18 Pages 184506,1-184506,8
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract In the framework of the time-dependent Ginzburg-Landau formalism, we study the resistive state of a submicron superconducting stripe in the presence of a longitudinal current. Sufficiently strong current leads to phase slippage between the leads, which is manifested as oppositely charged kinematic vortices moving in opposite directions perpendicular to applied drive. Depending on the distribution of superconducting current density the vortex-antivortex either nucleate in the middle of the stripe and are expelled laterally or enter on opposite sides of the sample and are driven together to annihilation. We distinguish between the two scenarios as a function of relevant parameters and show how the creation/annihilation point of the vortex-antivortex and their individual velocity can be manipulated by applied magnetic field and current.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000266501200091 Publication Date 2009-05-06
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 75 Open Access
Notes Approved (up) Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:77400 Serial 1756
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Author Pereira, J.M.; Peeters, F.M.; Vasilopoulos, P.; Costa Filho, R.N.; Farias, G.A.
Title Landau levels in graphene bilayer quantum dots Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 79 Issue 19 Pages 195403,1-195403,5
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We investigate localized electron and hole states in parabolic quantum dots of biased graphene bilayers in the presence of a perpendicular magnetic field. These quantum dots can be created by means of nanostructured gates or by position-dependent doping, which can create a gap in the otherwise gapless dispersion of a graphene bilayer. Numerical results show the energy levels of confined electrons and holes as a function of the dot parameters and the magnetic field. Remarkable crossings of energy levels are found.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000266501300102 Publication Date 2009-05-05
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 29 Open Access
Notes Approved (up) Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:77401 Serial 1774
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Author Zha, G.-Q.; Milošević, M.V.; Zhou, S.-P.; Peeters, F.M.
Title Magnetic flux periodicity in mesoscopic d-wave symmetric and asymmetric superconducting loops Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 80 Issue 14 Pages 144501,1-144501,5
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The magnetic flux dependence of energy and supercurrent in mesoscopic d-wave symmetric and asymmetric superconducting loops is investigated by numerically solving the Bogoliubov-de Gennes equations self-consistently. For square loops, we find an hc/e-flux periodicity in energy and supercurrent and demonstrate that the flux periodicity is sensitive to the hole size and the superconducting pairing strength as well as temperature. The hc/2e-periodic behavior can be restored almost entirely when we displace the central hole sufficiently out of the center of the sample. In rectangular loops, the discrete current-carrying low-energy spectrum can exist for an odd winding number of the order parameter.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000271351500085 Publication Date 2009-10-15
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 13 Open Access
Notes Approved (up) Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:79994 Serial 1879
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Author Nguten, N.T.T.; Peeters, F.M.
Title Many-body effects in the cyclotron resonance of a magnetic dot Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 80 Issue 11 Pages 115335,1-115335,9
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Intraband cyclotron resonance (CR) transitions of a two-electron quantum dot containing a single magnetic ion is investigated for different Coulomb interaction strengths and different positions of the magnetic ion. In contrast to the usual parabolic quantum dots where CR is independent of the number of electrons, we found here that due to the presence of the magnetic ion Kohn's theorem no longer holds and CR is different for systems with different number of electrons and different effective electron-electron Coulomb interaction strength. Many-body effects result in shifts in the transition energies and change the number of CR lines. The position of the magnetic ion inside the quantum dot affects the structure of the CR spectrum by changing the position and the number of crossings and anticrossings in the transition energies and oscillator strengths.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000270383200110 Publication Date 2009-09-30
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 6 Open Access
Notes Approved (up) Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:79228 Serial 1941
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Author Földi, P.; Benedict, M.G.; Kalman, O.; Peeters, F.M.
Title Quantum rings with time-dependent spin-orbit coupling: Spintronic Rabi oscillations and conductance properties Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 80 Issue 16 Pages 165303,1-165303,10
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The strength of the (Rashba-type) spin-orbit coupling in mesoscopic semiconductor rings can be tuned with external gate voltages. Here we consider the case of a periodically changing spin-orbit interaction strength in time as induced by sinusoidal voltages. In a closed one dimensional quantum ring with weak spin-orbit coupling, Rabi oscillations are shown to appear. We find that the time evolution of initially localized wave packets exhibits a series of collapse and revival phenomena. Partial revivalsthat are typical in nonlinear systemsare shown to correspond to superpositions of states localized at different spatial positions along the ring. These spintronic Schrödinger-cat states appear periodically, and similarly to their counterparts in other physical systems, they are found to be sensitive to disturbances caused by the environment. The time-dependent spin transport problem, when leads are attached to the ring, is also solved. We show that the sideband currents induced by the oscillating spin-orbit interaction strength can become the dominant output channel, even in the presence of moderate thermal fluctuations and random scattering events.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000271352100078 Publication Date 2009-10-12
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 26 Open Access
Notes Approved (up) Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:80002 Serial 2784
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Author Masir, M.R.; Matulis, A.; Peeters, F.M.
Title Quasibound states of Schrödinger and Dirac electrons in a magnetic quantum dot Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 79 Issue 15 Pages 155451,1-155451,8
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The properties of a two-dimensional electron are investigated in the presence of a circular step magnetic-field profile. Both electrons with parabolic dispersion as well as Dirac electrons with linear dispersion are studied. We found that in such a magnetic quantum dot no electrons can be confined. Nevertheless close to the Landau levels quasibound states can exist with a rather long lifetime.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000265944200140 Publication Date 2009-04-30
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 55 Open Access
Notes Approved (up) Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:77026 Serial 2800
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Author Geurts, R.; Milošević, M.V.; Peeters, F.M.
Title Second generation of vortex-antivortex states in mesoscopic superconductors: stabilization by artificial pinning Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 79 Issue 17 Pages 174508,1-174508,5
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Antagonistic symmetries of superconducting polygons and their induced multivortex states in a homogeneous magnetic field may lead to the appearance of antivortices in the vicinity of the superconducting/normal-state boundary (where mesoscopic confinement is particularly strong). Resulting vortex-antivortex (V-Av) molecules match the sample symmetry but are extremely sensitive to defects and fluctuations and remain undetected experimentally. Here we show that V-Av states can reappear deep in the superconducting state due to an array of perforations in a polygonal setting, surrounding a central hole. Such states are no longer caused by the symmetry of the sample but rather by pinning itself, which prevents the vortex-antivortex annihilation. As a result, even micron size, clearly spaced V-Av molecules can be stabilized in large mesoscopic samples.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000266501100098 Publication Date 2009-05-06
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 17 Open Access
Notes Approved (up) Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:77399 Serial 2956
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Author Szafran, B.; Nowak, M.P.; Bednarek, S.; Chwiej, T.; Peeters, F.M.
Title Selective suppression of Dresselhaus or Rashba spin-orbit coupling effects by the Zeeman interaction in quantum dots Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 79 Issue 23 Pages 235303,1-235303,13
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We study single- and two-electron parabolic quantum dots in the presence of linear Dresselhaus and Rashba spin-orbit interactions. Contributions of both types of spin-orbit coupling are investigated in the context of the spin polarization of the system at high magnetic fields. We demonstrate that for negative Landé factors the effect of the Dresselhaus coupling is suppressed at high magnetic field, which for structures without inversion asymmetry leads to a completely spin-polarized system and a strict antisymmetry of the wave functions with respect to the interchange of spatial-electron coordinates. For negative Landé factor the Rashba coupling is preserved at high field and consequently the spin polarization of the systems as well as the spatial antisymmetry of the two-electron wave function remain approximate.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000267699500073 Publication Date 2009-06-02
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 13 Open Access
Notes Approved (up) Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:77691 Serial 2969
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Author Hao, Y.L.; Djotyan, A.P.; Avetisyan, A.A.; Peeters, F.M.
Title Shallow donor states near a semiconductor-insulator-metal interface Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 80 Issue 3 Pages 035329,1-035329,10
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The lowest energy electronic states of a donor located near a semiconductor-insulator-metal interface are investigated within the effective mass approach. The effect of the finite thickness of the insulator between the semiconductor and the metallic gate on the energy levels is studied. The lowest energy states are obtained through a variational approach, which takes into account the influence of all image charges that arise due to the presence of the metallic and the dielectric interfaces. We compare our results with a numerical exact calculation using the finite element technique.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000268617800101 Publication Date 2009-07-30
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 22 Open Access
Notes Approved (up) Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:77950 Serial 2989
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Author Földi, P.; Kálmán, O.; Peeters, F.M.
Title Stability of spintronic devices based on quantum ring networks Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 80 Issue 12 Pages 125324,1-125324,9
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Transport properties in mesoscopic networks are investigated, where the strength of the (Rashba-type) spin-orbit coupling is tuned with external gate voltages. We analyze in detail to what extent the ideal behavior and functionality of some promising network-based devices are modified by random (spin-dependent) scattering events and by thermal fluctuations. It is found that although the functionality of these devices is obviously based on the quantum coherence of the transmitted electrons, there is a certain stability: moderate level of errors can be tolerated. For mesoscopic networks made of typical semiconductor materials, we found that when the energy distribution of the input carriers is narrow enough, the devices can operate close to their ideal limits even at relatively high temperature. As an example, we present results for two different networks: one that realizes a Stern-Gerlach device and another that simulates a spin quantum walker. Finally we propose a simple network that can act as a narrow band energy filter even in the presence of random scatterers.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000270383300091 Publication Date 2009-09-23
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 41 Open Access
Notes Approved (up) Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:79230 Serial 3131
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Author Croitoru, M.D.; Shanenko, A.A.; Kaun, C.C.; Peeters, F.M.
Title Superconducting nanowires: interplay of discrete transverse modes with supercurrent Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 80 Issue 2 Pages 024513,1-024513,11
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract From a numerical solution of the Bogoliubov-de Gennes equations, we investigate an interplay of the transverse discrete modes with a longitudinal supercurrent in a metallic cylindrical superconducting nanowire. The superconductor-to-normal transition induced by a longitudinal superflow of electrons is found to occur as a cascade of jumps in the order parameter (supercurrent and superfluid density) as a function of the superfluid velocity for diameters d<1015 nm (for Al parameters) and sufficiently low temperatures T<0.30.4Tc, with Tc the critical temperature. When approaching Tc, the jumps are smoothed into steplike but continuous drops. A similar picture occurs for d>1520 nm. Only when the diameter exceeds 5070 nm the quantum-size cascades are fully washed out, and we arrive at the mesoscopic regime. Below this regime the critical current density jc exhibits the quantum-size oscillations with pronounced resonant enhancements: the smaller the diameter, the more significant is the enhancement. Thickness fluctuations of real samples will smooth out such oscillations into an overall growth of jc with decreasing nanowire diameter.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000268617500092 Publication Date 2009-07-22
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 (up) Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:77949 Serial 3358
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Author Michel, K.H.; Verberck, B.
Title Theory of elastic and piezoelectric effects in two-dimensional hexagonal boron nitride Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 80 Issue 22 Pages 224301,1-224301,10
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Starting from an empirical force constant model of valence interactions and calculating by Ewalds method the ion-ion force constants, we derive the dynamical matrix for a monolayer crystal of hexagonal boron nitride (h-BN). The phonon dispersion relations are calculated. The interplay between valence and Coulomb forces is discussed. It is shown by analytical methods that the longitudinal and the transverse optical (LO and TO) phonon branches for in-plane motion are degenerate at the Γ point of the Brillouin zone. Away from Γ, the LO branch exhibits pronounced overbending. It is found that the nonanalytic Coulomb contribution to the dynamical matrix causes a linear increase of the LO branch with increasing wave vector starting at Γ. This effect is general for two-dimensional (2D) ionic crystals. Performing a long-wavelength expansion of the dynamical matrix, we use Borns perturbation method to calculate the elastic constants (tension coefficients). Since the crystal is noncentrosymmetric, internal displacements due to relative shifts between the two sublattices (B and N) contribute to the elastic constants. These internal displacements are responsible for piezoelectric and dielectric phenomena. The piezoelectric stress constant and the dielectric susceptibility of 2D h-BN are calculated.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000273228500045 Publication Date 2009-12-21
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 96 Open Access
Notes Approved (up) Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:80576 Serial 3616
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Author Karapetrov, G.; Milošević, M.V.; Iavarone, M.; Fedor, J.; Belkin, A.; Novosad, V.; Peeters, F.M.
Title Transverse instabilities of multiple vortex chains in magnetically coupled NbSe2/permalloy superconductor/ferromagnet bilayers Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 80 Issue 18 Pages 180506,1-180506,4
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using scanning tunneling microscopy and Ginzburg-Landau simulations, we explore vortex configurations in magnetically coupled NbSe2/permalloy superconductor/ferromagnet bilayer. The permalloy film with stripe domain structure induces periodic local magnetic induction in the superconductor, creating a series of pinning-antipinning channels for externally added magnetic flux quanta. Such laterally confined Abrikosov vortices form quasi-one-dimensional arrays (chains). The transitions between multichain states occur through propagation of kinks at the intermediate fields. At high fields we show that the system becomes nonlinear due to a change in both the number of vortices and the confining potential. The longitudinal instabilities of the resulting vortex structures lead to vortices levitating in the antipinning channels.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000272310900031 Publication Date 2009-11-18
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 38 Open Access
Notes Approved (up) Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:80314 Serial 3729
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Author Berdiyorov, G.R.; Milošević, M.V.; Peeters, F.M.
Title Tunable kinematics of phase-slip lines in a superconducting stripe with magnetic dots Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 80 Issue 21 Pages 214509,1-214509,7
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using numerical simulations, we study the dynamic properties of a superconducting stripe with a perpendicular magnetized ferromagnet on top in the presence of an applied dc current. In the resistive state conventional phase-slip lines are transformed into kinematic vortex-antivortex pairs with special dynamic behavior. In addition, the location of phase slippage in the sample is predetermined by the position of the magnetic dot. Both these effects directly influence the dynamics of the superconducting condensate and lead to periodic oscillations of the voltage across the sample with a frequency tunable both by the applied current and by the magnetization of the magnet. We found that the frequency of the voltage oscillations increases with increasing number of magnetic dots.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000273228200084 Publication Date 2009-12-09
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 33 Open Access
Notes Approved (up) Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:80575 Serial 3743
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Author Masir, M.R.; Vasilopoulos, P.; Peeters, F.M.
Title Tunneling, conductance, and wavevector filtering through magnetic barriers in bilayer graphene Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 79 Issue 3 Pages 035409,1-035409,8
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We evaluate the transmission and conductance through magnetic barrier structures in bilayer graphene. In particular we consider a magnetic step, single and double barriers, -function barriers, as well as barrier structures that have average magnetic field equal to zero. The transmission depends strongly on the direction of the incident electron or hole wavevector and gives the possibility to construct a direction-dependent wavevector filter. The results contrast sharply with previous results on single-layer graphene. In general, the angular range of perfect transmission becomes drastically wider and the gaps narrower. This perfect transmission range decreases with the number of barriers, the barrier width, and the magnetic field. Depending on the structure, a variety of transmission resonances occur that are reflected in the conductance through the structure.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000262978200107 Publication Date 2009-01-14
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 80 Open Access
Notes Approved (up) Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:75983 Serial 3762
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Author Pourghaderi, M.A.; Magnus, W.; Sorée, B.; Meuris, M.; de Meyer, K.; Heyns, M.
Title Tunneling-lifetime model for metal-oxide-semiconductor structures Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 80 Issue 8 Pages 085315,1-085315,10
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract In this paper we investigate the basic physics of charge carriers (electrons) leaking out of the inversion layer of a metal-oxide-semiconductor capacitor with a biased gate. In particular, we treat the gate leakage current as resulting from two combined processes: (1) the time-dependent decay of electron wave packets representing the inversion-layer charge and (2) the local generation of new electrons replacing those that have leaked away. As a result, the gate current simply emerges as the ratio of the total charge in the inversion layer to the tunneling lifetime. The latter is extracted from the quantum dynamics of the decaying wave packets, while the generation rate is incorporated as a phenomenological source term in the continuity equation. Not only do the gate currents calculated with this model agree very well with experiment, the model also provides an onset to solve the paradox of the current-free bound states representing the resonances of the Schrödinger equation that governs the fully coupled metal-oxide-semiconductor system.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000269639300076 Publication Date 2009-08-21
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 2 Open Access
Notes Approved (up) Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:78294 Serial 3763
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Author Leenaerts, O.; Partoens, B.; Peeters, F.M.
Title Water on graphene: hydrophobicity and dipole moment using density functional theory Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 79 Issue 23 Pages 235440,1-235440,5
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We apply density-functional theory to study the adsorption of water clusters on the surface of a graphene sheet and find i) graphene is highly hydrophobic and ii) adsorbed water has very little effect on the electronic structure of graphene. A single water cluster on graphene has a very small average dipole moment which is in contrast with an ice layer that exhibits a strong dipole moment.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000267699500147 Publication Date 2009-06-29
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 292 Open Access
Notes Approved (up) Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:77693 Serial 3904
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Author Chaves, A.; Farias, G.A.; Peeters, F.M.; Szafran, B.
Title Wave packet dynamics in semiconductor quantum rings of finite width Type A1 Journal article
Year 2009 Publication Physical review : B : solid state Abbreviated Journal Phys Rev B
Volume 80 Issue 12 Pages 125331,1-125331,14
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The time evolution of a wave packet injected into a semiconductor quantum ring is investigated in order to obtain the transmission and reflection probabilities. Within the effective-mass approximation, the time-dependent Schrödinger equation is solved for a system with nonzero width of the ring and leads and finite potential-barrier heights, where we include smooth lead-ring connections. In the absence of a magnetic field, an analysis of the projection of the wave function over the different subband states shows that when the injected wave packet is within a single subband, the junction can scatter this wave packet into different subbands but remarkably at the second junction the wave packet is scattered back into the subband state of the incoming wave packet. If a magnetic field is applied perpendicularly to the ring plane, transmission and reflection probabilities exhibit Aharonov-Bohm (AB) oscillations and the outgoing electrons may end up in different subband states from those of the incoming electrons. Localized impurities, placed in the ring arms, influence the AB oscillation period and amplitude. For a single impurity or potential barrier of sufficiently strong strength, the period of the AB oscillations is halved while for two impurities localized in diametrically opposite points of the ring, the original AB period is recovered. A theoretical investigation of the confined states and time evolution of wave packets in T wires is also made, where a comparison between this system and the lead-ring junction is drawn.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000270383300098 Publication Date 2009-09-25
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 40 Open Access
Notes Approved (up) Most recent IF: 3.836; 2009 IF: 3.475
Call Number UA @ lucian @ c:irua:79231 Serial 3906
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Author Xu, B.; Milošević, M.V.; Peeters, F.M.
Title Calorimetric properties of mesoscopic superconducting disks, rings, and cylinders Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 81 Issue 6 Pages 064501,1-064501,10
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The thermal signatures of superconductivity in mesoscopic disks, rings and cylinders are calculated within the Ginzburg-Landau theory. In an applied perpendicular magnetic field H the heat capacity of mesoscopic samples shows a strong dependence on the realized vortex state; discontinuities are found at the critical field for different vorticities, as well as at the superconducting-to-normal state transition. The same applies to the intermediate state of type-I superconductors. Even the subtle changes in the fluxoid distribution inside the sample leave clear signatures on heat capacity, which is particularly useful for fully three-dimensional samples whose interior is often inaccessible by magnetometry. The heat-capacity jump ΔC(H) at the critical temperature exhibits quasiperiodic modulations as a function of magnetic field. In mesoscopic superconducting rings, these oscillations provide calorimetric verification of the Little-Parks effect.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000274998100091 Publication Date 2010-02-01
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 17 Open Access
Notes ; We are grateful to O. Bourgeois for useful discussions. This work was supported by the Flemish Science Foundation (FWO-VI), the Interuniversity Attraction Poles (IAP) Program-Belgian State-Belgian Science Policy, ESF-JSPS NES program and the ESF-AQDJJ network. ; Approved (up) Most recent IF: 3.836; 2010 IF: 3.774
Call Number UA @ lucian @ c:irua:81766 Serial 271
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Author Kosimov, D.P.; Dzhurakhalov, A.A.; Peeters, F.M.
Title Carbon clusters: from ring structures to nanographene Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 81 Issue 19 Pages 195414,1-195414,12
Keywords A1 Journal article; Condensed Matter Theory (CMT); Integrated Molecular Plant Physiology Research (IMPRES); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The lowest-energy configurations of Cn(n≤55) clusters are obtained using the energy-minimization technique with the conjugate gradient method where a modified Brenner potential is invoked to describe the carbon and hydrocarbon interaction. We found that the ground-state configuration consists of a single ring for small number of C atoms and multiring structures are found with increasing n, which can be in planar, bowl-like or caplike form. Contrary to previous predictions, the binding energy Eb does not show even-odd oscillations and only small jumps are found in the Eb(n) curve as a consequence of specific types of edges or equivalently the number of secondary atoms. We found that hydrogenation of the edge atoms may change the ground-state configuration of the nanocluster. In both cases we determined the magic clusters. Special attention is paid to trigonal and hexagonal shaped carbon clusters and to clusters having a graphenelike configuration. Trigonal clusters are never the ground state while hexagonal-shaped clusters are only the ground state when they have zigzag edges.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000278142000103 Publication Date 2010-05-10
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 55 Open Access
Notes ; This work was supported by the Belgian Science Policy (IAP) and the Flemish Science Foundation (FWO-V1). ; Approved (up) Most recent IF: 3.836; 2010 IF: 3.774
Call Number UA @ lucian @ c:irua:83385 Serial 278
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Author Payette, C.; Amaha, S.; Yu, G.; Gupta, J.A.; Austing, D.G.; Nair, S.V.; Partoens, B.; Tarucha, S.
Title Coherent level mixing in dot energy spectra measured by magnetoresonant tunneling spectroscopy of vertical quantum dot molecules Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 81 Issue 24 Pages 245310,1-245310,15
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We study by magnetoresonant tunneling spectroscopy single-particle energy spectra of the constituent weakly coupled dots in vertical quantum dot molecules over a wide energy window. The measured energy spectra are well modeled by calculated spectra for dots with in-plane confinement potentials that are elliptical and parabolic in form. However, in the regions where two, three, or four single-particle energy levels are naively expected to cross, we observe pronounced level anticrossing behavior and strong variations in the resonant currents as a consequence of coherent mixing induced by small deviations in the nearly ideal dot confinement potentials. We present detailed analysis of the energy spectra, and focus on two examples of three-level crossings whereby the coherent mixing leads to concurrent suppression and enhancement of the resonant currents when the anticrossing levels are minimally separated. The suppression of resonant current is of particular interest since it is a signature of dark state formation due to destructive interference. We also describe in detail and compare two measurement strategies to reliably extract the resonant currents required to characterize the level mixing.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000278606100003 Publication Date 2010-06-10
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 6 Open Access
Notes ; We thank A. Bezinger, D. Roth, and M. Malloy for assistance with some of the processing, and K. Ono, T. Kodera, T. Hatano, Y. Tokura, M. Stopa, M. Hilke, G.C. Aers, M. Korkusinski, and R. M. Abolfath for useful discussions. Part of this work is supported by NSERC (Discovery Grant No. 208201), Flemish Science Foundation (FWO-VI), Grant-in-Aid for Scientific Research S (Grant No. 191040070), B (Grant No. 18340081), and by Special Coordination Funds for Promoting Science and Technology, and MEXT. S.T. acknowledges support from QuEST program (BAA-0824). ; Approved (up) Most recent IF: 3.836; 2010 IF: 3.774
Call Number UA @ lucian @ c:irua:83095 Serial 379
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Author Piacente, G.; Hai, G.Q.; Peeters, F.M.
Title Continuous structural transitions in quasi-one-dimensional classical Wigner crystals Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 81 Issue 2 Pages
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We study the structural phase transitions in confined systems of strongly interacting particles. We consider infinite quasi-one-dimensional systems with different pairwise repulsive interactions in the presence of an external confinement following a power law. Within the framework of Landaus theory, we find the necessary conditions to observe continuous transitions and demonstrate that the only allowed continuous transition is between the single- and the double-chain configurations and that it only takes place when the confinement is parabolic. We determine analytically the behavior of the system at the transition point and calculate the critical exponents. Furthermore, we perform Monte Carlo simulations and find a perfect agreement between theory and numerics.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000274002100035 Publication Date 2010-01-19
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 37 Open Access
Notes ; The authors acknowledge FAPESP and CNPq (Brazil), the Belgian Science Policy (IAP) and the Flemish Science Foundation (FWO-Vl) (Belgium) for financial support. ; Approved (up) Most recent IF: 3.836; 2010 IF: 3.774
Call Number UA @ lucian @ c:irua:81243 Serial 493
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Author Yang, C.H.; Peeters, F.M.; Xu, W.
Title Density of states and magneto-optical conductivity of graphene in a perpendicular magnetic field Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 82 Issue 20 Pages 205428
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The density of states (DOS) and the optical conductivity of graphene is calculated in the presence of a perpendicular magnetic field and where scattering on charged and short-range impurities is included. The standard Kubo formula is employed where the self-energy induced by impurity scattering and the Green's function are calculated self-consistently including inter-Landau level (LL) coupling and screening effects. It is found that the scattering from those two types of impurities results in a symmetric LL broadening and asymmetric inter-LL coupling renormalizes the LL positions to lower energy. The peak position and intensity of the magneto-optical conductivity depends on the filling factor and the broadened DOS. Good agreement is found with recent cyclotron resonance measurements.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000284400700003 Publication Date 2010-11-18
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 39 Open Access
Notes ; This work was supported by the National Natural Science Foundation of China under Grant No. 10804053, the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and the Chinese Academy of Sciences and Department of Science and Technology of Yunnan Province. ; Approved (up) Most recent IF: 3.836; 2010 IF: 3.774
Call Number UA @ lucian @ c:irua:95543 Serial 641
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Author Lin, N.S.; Misko, V.R.; Peeters, F.M.
Title Dynamics of multishell vortex structures in mesoscopic superconducting Corbino disks Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 81 Issue 13 Pages 134504,1-134504,11
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We study the dynamics of vortex shells in mesoscopic superconducting Corbino disks, where vortices form shells as recently observed in micrometer-sized Nb disks. Due to the interplay between the vortex-vortex interaction, the gradient Lorentz force and the (in)commensurability between the numbers of vortices in shells, the process of angular melting of vortex-shell configurations becomes complex. Angular melting can start either from the center of the disk (where the shear stress is maximum) or from its boundary (where the shear stress is minimum) depending on the specific vortex configuration. Furthermore, we found that two kinds of defects can exist in such vortex-shell structures: intrashell and intershell defects. An intrashell defect may lead to an inverse dynamic behavior, i.e., one of the vortex shells under a stronger driving force can rotate slower than the adjacent shell that is driven by a weaker Lorentz force. An intershell defect always locks more than two shells until the gradient of the Lorentz force becomes large enough to break the rigid-body rotation of the locked shells. Such a lock-unlock process leads to hysteresis in the angular velocities of the shells.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000277207900079 Publication Date 2010-04-02
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 11 Open Access
Notes ; This work was supported by the “Odysseus” program of the Flemish Government and the Flemish Science Foundation (FWO-V1), the Interuniversity Attraction Poles (IAP) Programme-Belgian State-Belgian Science Policy, and the FWO-V1. ; Approved (up) Most recent IF: 3.836; 2010 IF: 3.774
Call Number UA @ lucian @ c:irua:82803 Serial 779
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Author Wu, Z.; Peeters, F.M.; Chang, K.
Title Electron tunneling through double magnetic barriers on the surface of a topological insulator Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 82 Issue 11 Pages 115211-115211,7
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We study electron tunneling through a planar magnetic and electric barrier on the surface of a three-dimensional topological insulator. For the double barrier structures, we find (i) a directional-dependent tunneling which is sensitive to the magnetic field configuration and the electric gate voltage, (ii) a spin rotation controlled by the magnetic field and the gate voltage, (iii) many Fabry-Pérot resonances in the transmission determined by the distance between the two barriers, and (iv) the electrostatic potential can enhance the difference in the transmission between the two magnetization configurations, and consequently lead to a giant magnetoresistance. Points (i), (iii), and (iv) are alike with that in graphene stemming from the same linear-dispersion relations.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000282125700002 Publication Date 2010-09-27
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 65 Open Access
Notes ; This work was supported by the NSF of China, the Flemish Science Foundation (FWO-Vl), and the Belgian Science Policy. ; Approved (up) Most recent IF: 3.836; 2010 IF: 3.774
Call Number UA @ lucian @ c:irua:85420 Serial 990
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Author Peelaers, H.; Partoens, B.; Peeters, F.M.
Title Electronic and dynamical properties of Si/Ge core-shell nanowires Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 82 Issue 11 Pages 113411-113411,4
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Full ab initio techniques are applied to study the electronic and dynamical properties of free standing, hydrogen-passivated Si/Ge core-shell nanowires oriented along the [110] direction. All studied wires exhibit a direct band gap and are found to be structurally stable. The different contributions of the core and shell atoms to the phonon spectra are identified. The acoustic phonon velocities and the frequencies of some typical optical modes are compared with those of pure Si and Ge nanowires. These depend either on the concentration or on the type of core material. Optical modes are hardened and longitudinal acoustic velocities are softened with decreasing wire diameter.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000282270000001 Publication Date 2010-09-29
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 13 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and NOI-BOF (University of Antwerp). ; Approved (up) Most recent IF: 3.836; 2010 IF: 3.774
Call Number UA @ lucian @ c:irua:85421 Serial 995
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