toggle visibility
Search within Results:
Display Options:

Select All    Deselect All
 |   | 
Details
   print
  Records
Author Tsvyashchenko, A.V.; Nikolaev, A.V.; Velichkov, A.I.; Salamatin, A.V.; Fomicheva, L.N.; Ryasny, G.K.; Sorokin, A.A.; Kochetov, O.I.; Budzynski, M.; Michel, K.H.
  Title Lowering of the spatial symmetry at the gamma ->alpha phase transition in cerium Type A1 Journal article
  Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 82 Issue 9 Pages 1-4
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Using time-differential perturbed angular correlation spectroscopy we have measured the electric field gradient (EFG) at 111Cd probe nuclei in solid Ce in a pressure range up to 8 GPa. Covering various allotropic phases of Ce, we find that the value of the EFG in the cubic α phase is almost four times larger than in the cubic γ phase and close to values in the noncubic phases α′ and α″. These results together with the differences in time modulation of the spectra are interpreted as evidence for quadrupolar electronic charge-density ordering and symmetry lowering at the γ→α transition while the lattice remains face-centered cubic
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000282004400001 Publication Date 2010-09-16
  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 is supported by the Program of the Presidium of the Russian Academy of Sciences “Physics of Strongly Compressed Matter.” We are grateful to S. M. Stishov, B. Verberck, A. N. Grum-Grzhimailo, V. B. Brudanin and G. Heger for support of this work and discussion of the results. ; Approved Most recent IF: 3.836; 2010 IF: 3.774
  Call Number UA @ lucian @ c:irua:85464 Serial 1854
Permanent link to this record
 

 
Author Misko, V.R.; Nori, F.
  Title Magnetic flux pinning in superconductors with hyperbolic-tesselation arrays of pinning sites Type A1 Journal article
  Year 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 85 Issue 18 Pages 184506-184506,6
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract We study magnetic flux interacting with arrays of pinning sites (APSs) placed on vertices of hyperbolic tesselations (HTs). We show that, due to the gradient in the density of pinning sites, HT APSs are capable of trapping vortices for a broad range of applied magnetic fluxes. Thus, the penetration of magnetic field in HT APSs is essentially different from the usual scenario predicted by the Bean model. We demonstrate that, due to the enhanced asymmetry of the surface barrier for vortex entry and exit, this HT APS could be used as a “capacitor” to store magnetic flux.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000303653600005 Publication Date 2012-05-04
  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 24 Open Access
  Notes ; V.R.M. acknowledges support from the “Odysseus” Program of the Flemish Government & FWO-Vl, and the IAP. F.N. is partially supported by the ARO, NSF Grant No. 0726909, JSPS-RFBR Contract No. 12-02-92100, Grant-in-Aid for Scientific Research (S), MEXT Kakenhi on Quantum Cybernetics, and the JSPS via its FIRST program. ; Approved Most recent IF: 3.836; 2012 IF: 3.767
  Call Number UA @ lucian @ c:irua:98224 Serial 1880
Permanent link to this record
 

 
Author Tahir, M.; Vasilopoulos, P.; Peeters, F.M.
  Title Magneto-optical transport properties of monolayer phosphorene Type A1 Journal article
  Year 2015 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 92 Issue 92 Pages 045420
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract The electronic properties of monolayer phosphorene are exotic due to its puckered structure and large intrinsic direct band gap. We derive and discuss its band structure in the presence of a perpendicular magnetic field. Further, we evaluate the magneto-optical Hall and longitudinal optical conductivities as functions of temperature, magnetic field, and Fermi energy, and show that they are strongly influenced by the magnetic field. The imaginary part of the former and the real part of the latter exhibit regular interband oscillations as functions of the frequency omega in the range (h) over bar omega similar to 1.5-2 eV. Strong intraband responses in the latter and weak ones in the former occur at much lower frequencies. The magneto-optical response can be tuned in the microwave-to-terahertz and visible frequency ranges in contrast with a conventional two-dimensional electron gas or graphene in which the response is limited to the terahertz regime. This ability to isolate carriers in an anisotropic structure may make phosphorene a promising candidate for new optical devices.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000358373600003 Publication Date 2015-07-23
  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 68 Open Access
  Notes ; This work was supported by the the Canadian NSERC Grant No. OGP0121756 (M.T., P.V.) and by the Flemish Science Foundation (FWO-Vl) (F.M.P.). ; Approved Most recent IF: 3.836; 2015 IF: 3.736
  Call Number c:irua:127192 Serial 1903
Permanent link to this record
 

 
Author Kálmán, O.; Földi, P.; Benedict, M.G.; Peeters, F.M.
  Title Magnetoconductance of rectangular arrays of quantum rings Type A1 Journal article
  Year 2008 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 78 Issue 12 Pages 125306-125306,10
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Electron transport through multiterminal rectangular arrays of quantum rings is studied in the presence of Rashba-type spin-orbit interaction (SOI) and of a perpendicular magnetic field. Using the analytic expressions for the transmission and reflection coefficients for single rings we obtain the conductance through such arrays as a function of the SOI strength, of the magnetic flux, and of the wave vector k of the incident electron. Due to destructive or constructive spin interferences caused by the SOI, the array can be totally opaque for certain ranges of k, while there are parameter values where it is completely transparent. Spin resolved transmission probabilities show nontrivial spin transformations at the outputs of the arrays. When pointlike random scattering centers are placed between the rings, the Aharonov-Bohm peaks split, and an oscillatory behavior of the conductance emerges as a function of the SOI strength.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000259691500047 Publication Date 2008-09-05
  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 31 Open Access
  Notes Approved Most recent IF: 3.836; 2008 IF: 3.322
  Call Number UA @ lucian @ c:irua:94598 Serial 1913
Permanent link to this record
 

 
Author Çakir, D.; Otalvaro, D.M.; Brocks, G.
  Title Magnetoresistance in multilayer fullerene spin valves: A first-principles study Type A1 Journal article
  Year 2014 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 90 Issue 24 Pages 245404
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Carbon-based molecular semiconductors are explored for application in spintronics because their small spinorbit coupling promises long spin lifetimes. We calculate the electronic transport from first principles through spin valves comprising bi-and tri-layers of the fullerene molecules C-60 and C-70, sandwiched between two Fe electrodes. The spin polarization of the current, and the magnetoresistance depend sensitively on the interactions at the interfaces between the molecules and the metal surfaces. They are much less affected by the thickness of the molecular layers. A high current polarization (CP > 90%) and magnetoresistance (MR > 100%) at small bias can be attained using C-70 layers. In contrast, the current polarization and the magnetoresistance at small bias are vanishingly small for C-60 layers. Exploiting a generalized Julliere model we can trace the differences in spin-dependent transport between C-60 and C-70 layers to differences between the molecule-metal interface states. These states also allow one to interpret the current polarization and the magnetoresistance as a function of the applied bias voltage.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000345875200005 Publication Date 2014-12-02
  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 Most recent IF: 3.836; 2014 IF: 3.736
  Call Number UA @ lucian @ c:irua:122177 Serial 1928
Permanent link to this record
 

 
Author Berdiyorov, G.R.; Chao, X.H.; Peeters, F.M.; Wang, H.B.; Moshchalkov, V.V.; Zhu, B.Y.
  Title Magnetoresistance oscillations in superconducting strips : a Ginzburg-Landau study Type A1 Journal article
  Year 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 86 Issue 22 Pages 224504-224508
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Within the time-dependent Ginzburg-Landau theory we study the dynamic properties of current-carrying superconducting strips in the presence of a perpendicular magnetic field. We found pronounced voltage peaks as a function of the magnetic field, the amplitude of which depends both on sample dimensions and external parameters. These voltage oscillations are a consequence of moving vortices, which undergo alternating static and dynamic phases. At higher fields or for high currents, the continuous motion of vortices is responsible for the monotonic background on which the resistance oscillations due to the entry of additional vortices are superimposed. Mechanisms for such vortex-assisted resistance oscillations are discussed. Qualitative changes in the magnetoresistance curves are observed in the presence of random defects, which affect the dynamics of vortices in the system.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000312064300004 Publication Date 2012-12-10
  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 31 Open Access
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the ESF-NES program. G. R. B. acknowledges support from FWO-Vl. B.Y.Z. acknowledges the support from the MOST 973 Projects No. 2011CBA00110 and No. 2009CB930803, and the National Natural Science Foundation of China. V. V. M. acknowledges support from the Methusalem Funding by the Flemish Government. ; Approved Most recent IF: 3.836; 2012 IF: 3.767
  Call Number UA @ lucian @ c:irua:105969 Serial 1930
Permanent link to this record
 

 
Author van der Burgt, M.; Karavolas, V.C.; Peeters, F.M.; Singleton, J.; Nicholas, R.J.; Herlach, F.; Harris, J.J.; Van Hove, M.; Borghs, G.
  Title Magnetotransport in a pseudomorphic GaAs/Ga0.8In0.2As/Ga0.75Al0.25As heterostructure with a Si \delta-doping layer Type A1 Journal article
  Year 1995 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 52 Issue 16 Pages 12218-12231
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Magnetotransport properties of a pseudomorphic GsAs/Ga0.8In0.2As/Ga0.75Al0.25As heterostructure are investigated in pulsed magnetic fields up to 50 T and at temperatures of T = 1.4 and 4.2 K. The structure studied consists of a Si delta layer parallel to a Ga0.8In0.2As quantum well (QW). The dark electron density of the structure is n(c) = 1.67 x 10(16) m(-2). By illumination the density can be increased up to a factor of 4; this way the second subband in the Ga0.08In0.2As QW can become populated as well as the Si delta layer. The presence of electrons in the delta layer results in drastic changes in the transport data, especially at magnetic fields beyond 30 T. The phenomena observed are interpreted as (i) magnetic freeze-out of carriers in the delta layer when a low density of electrons is present in the delta layer, and (ii) quantization of the electron motion in the two-dimensional electron gases in both the Ga0.8In0.2As QW and the Si delta layer in the case of high densities. These conclusions are corroborated by the numerical results of our theoretical model. We obtain satisfactory agreement between model and experiment.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos A1995TB96600102 Publication Date 2002-07-27
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0163-1829;1095-3795; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.736 Times cited 43 Open Access
  Notes Approved PHYSICS, APPLIED 28/145 Q1 #
  Call Number UA @ lucian @ c:irua:99708 Serial 1933
Permanent link to this record
 

 
Author Zarenia, M.; Vasilopoulos, P.; Peeters, F.M.
  Title Magnetotransport in periodically modulated bilayer graphene Type A1 Journal article
  Year 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 85 Issue 24 Pages 245426-245426,10
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Magnetotransport in bilayer graphene in the presence of a weak and periodic potential is investigated in the presence of a perpendicular magnetic field B. The modulation broadens the Landau levels into bands and for weak magnetic fields leads to the well-known Weiss oscillations in their bandwidth and their transport coefficients at very low B and to the Shubnikov-de Haas oscillations at larger B. The amplitude of the Weiss oscillations is severely reduced if the periodic potentials applied to the two layers oscillate out of phase. We also contrast some results with those corresponding to single-layer graphene. Relative to them the flat-band condition and the oscillation amplitude differ substantially, due to the interlayer coupling, and agree only when this coupling is extremely weak. We further show that the Hall conductivity exhibits the well-known steps at half-integer and integer multiples of 4e(2)/h in single-layer and bilayer graphene, respectively, even for very weak magnetic fields. The results are pertinent to weak and periodic corrugations when the potential modulation dominates the strain-induced magnetic modulation.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000305253600012 Publication Date 2012-06-14
  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 21 Open Access
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl), the European Science Foundation (ESF) under the EUROCORES program EuroGRAPHENE (project CON-GRAN), and the Canadian NSERC Grant No. OGP0121756. ; Approved Most recent IF: 3.836; 2012 IF: 3.767
  Call Number UA @ lucian @ c:irua:99077 Serial 1934
Permanent link to this record
 

 
Author Zha, G.-Q.; Covaci, L.; Peeters, F.M.; Zhou, S.-P.
  Title Majorana fermion states and fractional flux periodicity in mesoscopic d-wave superconducting loops with spin-orbit interaction Type A1 Journal article
  Year 2014 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 90 Issue 1 Pages 014522
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract We numerically investigate the spin-orbit (SO) coupling effect on the magnetic flux evolution of energy and supercurrent in mesoscopic d-wave superconducting loops by solving the spin-generalized Bogoliubov-de Gennes equations self-consistently. It is found that the energy spectrum splits when the SO interaction is involved and the Majorana zero mode can be realized in the [100] edges of square systems for an appropriate SO coupling strength. Superconducting phase transitions appear when the energy gap closes, accompanied by energy jumps between different energy parabolas in the ground state, which provides a possible mechanism to support fractional flux periodicity of supercurrent. Moreover, in the case of rectangular loops with SO coupling, the jumps of the ground-state energy gradually disappear by increasing the ratio of length to height of the sample, and a paramagnetic response with opposite direction of the screening current around zero flux value can occur in such systems.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000341233800010 Publication Date 2014-07-31
  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 7 Open Access
  Notes ; This work was supported by National Natural Science Foundation of China under Grants No. 61371020 and No. 61271163, by Visiting Scholar Program of Shanghai Municipal Education Commission, by Innovation Program of Shanghai Municipal Education Commission under Grant No. 13YZ006, and by the Flemish Science Foundation (FWO-Vl). ; Approved Most recent IF: 3.836; 2014 IF: 3.736
  Call Number UA @ lucian @ c:irua:119266 Serial 1938
Permanent link to this record
 

 
Author Kirilenko, D.A.; Dideykin, A.T.; Van Tendeloo, G.
  Title Measuring the corrugation amplitude of suspended and supported graphene Type A1 Journal article
  Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 84 Issue 23 Pages 235417-235417,5
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Nanoscale corrugation is a fundamental property of graphene arising from its low-dimensional nature. It places a fundamental limit to the conductivity of graphene and influences its properties. However the degree of the influence of the corrugation has not been well established because of the little knowledge about its spectrum in suspended graphene. We present a transmission electron microscopy technique that enables us to measure the average corrugation height and length. We applied the technique also to measure the temperature dependence of the corrugation. The difference in corrugation between suspended and supported graphene has been illustrated.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000297764700003 Publication Date 2011-12-03
  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; 2011 IF: 3.691
  Call Number UA @ lucian @ c:irua:93629 Serial 1971
Permanent link to this record
 

 
Author Singh, S.K.; Neek-Amal, M.; Peeters, F.M.
  Title Melting of graphene clusters Type A1 Journal article
  Year 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 87 Issue 13 Pages 134103-134109
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Density-functional tight-binding and classical molecular dynamics simulations are used to investigate the structural deformations and melting of planar carbon nanoclusters C-N with N = 2-55. The minimum-energy configurations for different clusters are used as starting configurations for the study of the temperature effects on the bond breaking and rotation in carbon lines (N < 6), carbon rings (5 < N < 19), and graphene nanoflakes. The larger the rings (graphene nanoflakes) the higher the transition temperature (melting point) with ring-to-line (perfect-to-defective) transition structures. The melting point was obtained by using the bond energy, the Lindemann criteria, and the specific heat. We found that hydrogen-passivated graphene nanoflakes (CNHM) have a larger melting temperature with a much smaller dependence on size. The edges in the graphene nanoflakes exhibit several different metastable configurations (isomers) during heating before melting occurs. DOI: 10.1103/PhysRevB.87.134103
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000317390700001 Publication Date 2013-04-11
  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 28 Open Access
  Notes ; This work was supported by the EU-Marie Curie IIF Postdoctoral Fellowship No. 299855 (for M.N.-A.), the ESF-EuroGRAPHENE Project CONGRAN, the Flemish Science Foundation (FWO-Vl), and the Methusalem Foundation of the Flemish Government. ; Approved Most recent IF: 3.836; 2013 IF: 3.664
  Call Number UA @ lucian @ c:irua:108467 Serial 1987
Permanent link to this record
 

 
Author Neek-Amal, M.; Xu, P.; Qi, D.; Thibado, P.M.; Nyakiti, L.O.; Wheeler, V.D.; Myers-Ward, R.L.; Eddy, C.R.; Gaskill, D.K.; Peeters, F.M.
  Title Membrane amplitude and triaxial stress in twisted bilayer graphene deciphered using first-principles directed elasticity theory and scanning tunneling microscopy Type A1 Journal article
  Year 2014 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 90 Issue 6 Pages 064101
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Twisted graphene layers produce a moire pattern (MP) structure with a predetermined wavelength for a given twist angle. However, predicting the membrane corrugation amplitude for any angle other than pure AB-stacked or AA-stacked graphene is impossible using first-principles density functional theory (DFT) due to the large supercell. Here, within elasticity theory, we define the MP structure as the minimum-energy configuration, thereby leaving the height amplitude as the only unknown parameter. The latter is determined from DFT calculations for AB-and AA-stacked bilayer graphene in order to eliminate all fitting parameters. Excellent agreement with scanning tunneling microscopy results across multiple substrates is reported as a function of twist angle.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000339995800001 Publication Date 2014-08-01
  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 12 Open Access
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem Foundation of the Flemish Government. M.N.-A. was supported by the EU-Marie Curie IIF postdoctoral Fellowship No. 299855. P.M.T. is thankful for the financial support of the Office of Naval Research under Grant No. N00014-10-1-0181 and the National Science Foundation under Grant No. DMR-0855358. L.O.N. acknowledges the support of the American Society for Engineering Education and Naval Research Laboratory Postdoctoral Fellow Program. Work at the US Naval Research Laboratory is supported by the Office of Naval Research. ; Approved Most recent IF: 3.836; 2014 IF: 3.736
  Call Number UA @ lucian @ c:irua:118774 Serial 1991
Permanent link to this record
 

 
Author Maignan, A.; Lebedev, O.I.; Van Tendeloo, G.; Martin, C.; Hebert, S.
  Title Metal to insulator transition in the n-type hollandite vanadate Pb1.6V8O16 Type A1 Journal article
  Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 82 Issue 3 Pages 035122, 1-035122,5
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract The transport and magnetic measurements of polycrystalline Pb1.6V8O16 hollandite reveal a concomitant metal to insulator and antiferromagnetic transition at TMI≈140 K. A clear localization is found below TMI, evidenced by a rapid increase in the absolute value of the negative Seebeck coefficient. The structural study by x-ray and transmission electron microscopy confirms the hollandite structure and shows that no structural transition occurs at TMI, ruling out a possible charge orbital ordering. The negative Seebeck coefficient observed from 50 K up to 900 K, with values reaching S=−38 μV K−1 at 900 K, is explained by the electron doping of ∼1.4e− in the V empty t2g orbitals responsible for the bad metal resistivity (ρ900 K∼2 mΩ cm). As this S value is close to that obtained by considering only the spin and orbital degeneracies, it is expected that |S| for such vanadates will not be sensitive at high temperature to the t2g band filling
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000280366300002 Publication Date 2010-07-27
  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 10 Open Access
  Notes Approved Most recent IF: 3.836; 2010 IF: 3.774
  Call Number UA @ lucian @ c:irua:84065 Serial 2009
Permanent link to this record
 

 
Author Croitoru, M.D.; Shanenko, A.A.; Kaun, C.C.; Peeters, F.M.
  Title Metallic nanograins : spatially nonuniform pairing induced by quantum confinement Type A1 Journal article
  Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 83 Issue 21 Pages 214509-214509,12
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract It is well known that the formation of discrete electron levels strongly influences the pairing in metallic nanograins. Here, we focus on another effect of quantum confinement in superconducting grains that was not studied previously, i.e., spatially nonuniform pairing. This effect is very significant when single-electron levels form bunches and/or a kind of shell structure. We find that, in highly symmetric grains, the order parameter can exhibit variations with position by an order of magnitude. Nonuniform pairing is closely related to a quantum-confinement-induced modification of the pairing-interaction matrix elements and size-dependent pinning of the chemical potential to groups of degenerate or nearly degenerate levels. For illustrative purposes, we consider spherical metallic nanograins and also rectangular shapes. We show that the relevant matrix elements are, as a rule, enhanced in the presence of quantum confinement, which favors spatial variations of the order parameter, compensating the corresponding energy cost. The size-dependent pinning of the chemical potential further increases the spatial variation of the pair condensate. The role of nonuniform pairing is smaller in less symmetric confining geometries and/or in the presence of disorder. However, it always remains of importance when the energy spacing between discrete electron levels δ is approaching the scale of the bulk gap ΔB, i.e., δ>0.10.2 ΔB.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000291310000006 Publication Date 2011-06-06
  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 23 Open Access
  Notes ; This work was supported by the Alexander von Humboldt Foundation, the Flemish Science Foundation (FWO-VI), and the Belgian Science Policy (IAP). M. D. C. acknowledges support of the European Community under a Marie Curie IEF Action (Grant Agreement No. PIEF-GA-2009-235486-ScQSR). ; Approved Most recent IF: 3.836; 2011 IF: 3.691
  Call Number UA @ lucian @ c:irua:90081 Serial 2010
Permanent link to this record
 

 
Author Boullay, P.; David, A.; Sheets, W.C.; Lüders, U.; Prellier, W.; Tan, H.; Verbeeck, J.; Van Tendeloo, G.; Gatel, C.; Vincze, G.; Radi, Z.
  Title Microstructure and interface studies of LaVO3/SrVO3 superlattices Type A1 Journal article
  Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 83 Issue 12 Pages 125403-125403,6
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract The structure and interface characteristics of (LaVO3)6m(SrVO3)m superlattices deposited on a (100)-SrTiO3 substrate were studied using transmission electron microscopy (TEM). Cross-section TEM studies revealed that both LaVO3 (LVO) and SrVO3 (SVO) layers are good single-crystal quality and epitaxially grown with respect to the substrate. It is evidenced that LVO layers are made of two orientational variants of a distorted perovskite compatible with bulk LaVO3, while SVO layers suffers from a tetragonal distortion due to the substrate-induced stain. Electron energy loss spectroscopy investigations indicate changes in the fine structure of the V L23 edge, related to a valence change between the LaVO3 and the SrVO3 layers.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000288160300006 Publication Date 2011-03-09
  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 26 Open Access
  Notes Fwo; Esteem 026019 Approved Most recent IF: 3.836; 2011 IF: 3.691
  Call Number UA @ lucian @ c:irua:88648UA @ admin @ c:irua:88648 Serial 2054
Permanent link to this record
 

 
Author Van Gompel, M.; Atalay, A.Y.; Gaulke, A.; Van Bael, M.K.; D'Haen, J.; Turner, S.; Van Tendeloo, G.; Vanacken, J.; Moshchalkov, V.V.; Wagner, P.
  Title Morphological TEM studies and magnetoresistance analysis of sputtered Al-substituted ZnO films : the role of oxygen Type A1 Journal article
  Year 2015 Publication Physica status solidi : A : applications and materials science Abbreviated Journal Phys Status Solidi A
  Volume 212 Issue 212 Pages 1191-1201
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract In this article, we report on the synthesis of thin, epitaxial films of the transparent conductive oxide Al:ZnO on (0001)-oriented synthetic sapphire substrates by DC sputtering from targets with a nominal 1 at.% Al substitution. The deposition was carried out at an unusually low substrate temperature of only 250 °C in argonoxygen mixtures as well as in pure argon. The impact of the processgas composition on the morphology was analysed by transmission electron microscopy, revealing epitaxial growth in all the cases with a minor impact of the process parameters on the resulting grain sizes. The transport properties resistivity, Hall effect and magnetoresistance were studied in the range from 10 to 300 K in DC and pulsed magnetic fields up to 45 T. While the carrier density and mobility are widely temperature independent, we identified a low fieldlow temperature regime in which the magnetoresistance shows an anomalous, negative behaviour. At higher fields and temperatures, the magnetoresistance exhibits a more conventional, positive curvature with increasing field strength. As a possible explanation, we propose carrier scattering at localised magnetic trace impurities and magnetic correlations.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000356706500003 Publication Date 2015-04-21
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1862-6300; ISBN Additional Links UA library record; WoS full record
  Impact Factor 1.775 Times cited Open Access
  Notes Methusalem project NANO; FWO; 246791 COUNTATOMS Approved Most recent IF: 1.775; 2015 IF: 1.616
  Call Number c:irua:126732 Serial 2204
Permanent link to this record
 

 
Author Van Duppen, B.; Sena, S.H.R.; Peeters, F.M.
  Title Multiband tunneling in trilayer graphene Type A1 Journal article
  Year 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 87 Issue 19 Pages 195439-10
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract The electronic tunneling properties of the two stable forms of trilayer graphene (TLG), rhombohedral ABC and Bernal ABA, are examined for p-n and p-n-p junctions as realized by using a single gate (SG) or a double gate (DG). For the rhombohedral form, due to the chirality of the electrons, the Klein paradox is found at normal incidence for SG devices, while at high-energy interband scattering between additional propagation modes can occur. The electrons in Bernal ABA TLG can have a monolayer- or bilayer-like character when incident on a SG device. Using a DG, however, both propagation modes will couple by breaking the mirror symmetry of the system, which induces intermode scattering and resonances that depend on the width of the DG p-n-p junction. For ABC TLG the DG opens up a band gap which suppresses Klein tunneling. The DG induces also an unexpected asymmetry in the tunneling angle for single-valley electrons.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000319281700004 Publication Date 2013-05-23
  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 13 Open Access
  Notes ; This work was supported by the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE within the project CONGRAN, the Flemish Science Foundation (FWO-VI) by an aspirant research grant to B. Van Duppen and the Methusalem Programme of the Flemish Government. ; Approved Most recent IF: 3.836; 2013 IF: 3.664
  Call Number UA @ lucian @ c:irua:108998 Serial 2216
Permanent link to this record
 

 
Author Lobato, I.; Partoens, B.
  Title Multiple Dirac particles in AA-stacked graphite and multilayers of graphene Type A1 Journal article
  Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 83 Issue 16 Pages 165429-165429,9
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
  Abstract Using the tight-binding formalism we show that in the recently experimentally realized AA-stacked graphite in essence two types of massless relativistic Dirac particles are present with a different effective speed of light. We also investigate how the electronic structure evolves from a single graphene sheet into AA-stacked graphite. It is shown that in contrast to AB-stacked graphene layers, the spectrum of AA-stacked graphene layers can be considered as a superposition of single-layer spectra and only particles with a linear spectrum at the Fermi energy around the K point are present. From the evolution of the band overlap we show that 6 multilayers of AA-stacked graphene already behave as AA-stacked graphite. The evolution of the effective speeds of light of the Dirac particles to their bulk values shows exactly the same behavior. The tight-binding parameters we use to describe AA-stacked graphite and multilayers of graphene are obtained by ab initio calculations.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000290113900005 Publication Date 2011-04-21
  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 68 Open Access
  Notes ; ; Approved Most recent IF: 3.836; 2011 IF: 3.691
  Call Number UA @ lucian @ c:irua:89717 Serial 2225
Permanent link to this record
 

 
Author Vodolazov, D.Y.; Peeters, F.M.; Dubonos, S.V.; Geim, A.K.
  Title Multiple flux jumps and irreversible behavior of thin Al superconducting rings Type A1 Journal article
  Year 2003 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 67 Issue 5 Pages 054506-6
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract An experimental and theoretical investigation was made of flux jumps and irreversible magnetization curves of mesoscopic Al superconducting rings. In the small magnetic-field region the change of vorticity with magnetic field can be larger than unity. This behavior is connected with the existence of several metastable states of different vorticities. The intentional introduction of a defect in the ring has a large effect on the size of the flux jumps. Calculations based on the time-dependent Ginzburg-Landau model allows us to explain the experimental results semiquantitatively.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000181360300061 Publication Date 2003-02-22
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 0163-1829;1095-3795; ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor 3.836 Times cited 49 Open Access
  Notes Approved Most recent IF: 3.836; 2003 IF: NA
  Call Number UA @ lucian @ c:irua:102812 Serial 2227
Permanent link to this record
 

 
Author Jorissen, K.; Rehr, J.J.; Verbeeck, J.
  Title Multiple scattering calculations of relativistic electron energy loss spectra Type A1 Journal article
  Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 81 Issue 15 Pages 155108,1-155108,6
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract A generalization of the real-space Greens-function approach is presented for ab initio calculations of relativistic electron energy loss spectra (EELS) which are particularly important in anisotropic materials. The approach incorporates relativistic effects in terms of the transition tensor within the dipole-selection rule. In particular, the method accounts for relativistic corrections to the magic angle in orientation resolved EELS experiments. The approach is validated by a study of the graphite C  K edge, for which we present an accurate magic angle measurement consistent with the predicted value.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000277210500038 Publication Date 2010-04-13
  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 24 Open Access
  Notes Fwo; Esteem 026019 Approved Most recent IF: 3.836; 2010 IF: 3.774
  Call Number UA @ lucian @ c:irua:82805UA @ admin @ c:irua:82805 Serial 2230
Permanent link to this record
 

 
Author Neek-Amal, M.; Peeters, F.M.
  Title Nanoindentation of a circular sheet of bilayer graphene Type A1 Journal article
  Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 81 Issue 23 Pages 235421,1-235421,6
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Nanoindentation of bilayer graphene is studied using molecular-dynamics simulations. We compared our simulation results with those from elasticity theory as based on the nonlinear Föppl-Hencky equations with rigid boundary condition. The force-deflection values of bilayer graphene are compared to those of monolayer graphene. Youngs modulus of bilayer graphene is estimated to be 0.8 TPa which is close to the value for graphite. Moreover, an almost flat bilayer membrane at low temperature under central load has a 14% smaller Youngs modulus as compared to the one at room temperature.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000278710800003 Publication Date 2010-06-11
  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 108 Open Access
  Notes ; We gratefully acknowledge comments from R. Asgari. M.N.-A. would like to thank the Universiteit of Antwerpen for its hospitality where part of this work was performed. This work was supported by the Flemish science foundation (FWO-V1) and the Belgium Science Policy (IAP). ; Approved Most recent IF: 3.836; 2010 IF: 3.774
  Call Number UA @ lucian @ c:irua:83093 Serial 2259
Permanent link to this record
 

 
Author Esfahani, D.N.; Covaci, L.; Peeters, F.M.
  Title Nonlinear response to electric field in extended Hubbard models Type A1 Journal article
  Year 2014 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 90 Issue 20 Pages 205121
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract The electric-field response of a one-dimensional ring of interacting fermions, where the interactions are described by the extended Hubbard model, is investigated. By using an accurate real-time propagation scheme based on the Chebyshev expansion of the evolution operator, we uncover various nonlinear regimes for a range of interaction parameters that allows modeling of metallic and insulating (either charge density wave or spin density wave insulators) rings. The metallic regime appears at the phase boundary between the two insulating phases and provides the opportunity to describe either weakly or strongly correlated metals. We find that the fidelity susceptibility of the ground state as a function of magnetic flux piercing the ring provides a very good measure of the short-time response. Even completely different interacting regimes behave in a similar manner at short time scales as long as the ground-state fidelity susceptibility is the same. Depending on the strength of the electric field we find various types of responses: persistent currents in the insulating phase, a dissipative regime, or damped Bloch-like oscillations with varying frequencies or even irregular in nature. Furthermore, we also consider the dimerization of the ring and describe the response of a correlated band insulator. In this case the distribution of the energy levels is more clustered and the Bloch-like oscillations become even more irregular.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000345423300002 Publication Date 2014-11-15
  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 3 Open Access
  Notes ; This work was supported by the Flemish Science Foundation (Fonds Wetenschappelijk Onderzoek – FWO) and the Methusalem program of the Flemish government. One of us (L. C.) receives support as a postdoctoral fellow of the FWO. ; Approved Most recent IF: 3.836; 2014 IF: 3.736
  Call Number UA @ lucian @ c:irua:122204 Serial 2355
Permanent link to this record
 

 
Author Xu, W.; Dong, H.M.; Li, L.L.; Yao, J.Q.; Vasilopoulos, P.; Peeters, F.M.
  Title Optoelectronic properties of graphene in the presence of optical phonon scattering Type A1 Journal article
  Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 82 Issue 12 Pages 125304-125304,9
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract We study in detail the optoelectronic properties of graphene. Considering the electron interactions with photons and phonons, we employ the mass- and energy-balance equations to self-consistently evaluate the photoinduced carrier densities, the optical conductance, and the transmission coefficient in the presence of a linearly polarized radiation field. We demonstrate that the photoinduced carrier densities increase around the electron-photon-phonon resonant transition. They depend strongly on the radiation intensity and frequency, temperature, and dark carrier density. For short-wavelength radiation (L<3 μm), we obtain the universal optical conductance σ0=e2/(4ℏ). Importantly, there exists an optical-absorption window in the radiation wavelength range 4100 μm, which is induced by different transition energies required for interband and intraband optical absorption. The position and width of this window depend sensitively on the temperature and the carrier density of the system. These theoretical results are in line with recent experimental findings and indicate that graphene exhibits important features not only in the visible regime but also in the midinfrared bandwidth.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000281516500009 Publication Date 2010-09-03
  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 28 Open Access
  Notes ; This work was supported by the Chinese Academy of Sciences, National Natural Science Foundation of China, and Department of Science and Technology of Yunnan Province. ; Approved Most recent IF: 3.836; 2010 IF: 3.774
  Call Number UA @ lucian @ c:irua:84260 Serial 2496
Permanent link to this record
 

 
Author Grujić, M.M.; Tadić, M.Z.; Peeters, F.M.
  Title Orbital magnetic moments in insulating Dirac systems : impact on magnetotransport in graphene van der Waals heterostructures Type A1 Journal article
  Year 2014 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 90 Issue 20 Pages 205408
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract In honeycomb Dirac systems with broken inversion symmetry, orbital magnetic moments coupled to the valley degree of freedom arise due to the topology of the band structure, leading to valley-selective optical dichroism. On the other hand, in Dirac systems with prominent spin-orbit coupling, similar orbital magnetic moments emerge as well. These moments are coupled to spin, but otherwise have the same functional form as the moments stemming from spatial inversion breaking. After reviewing the basic properties of these moments, which are relevant for a whole set of newly discovered materials, such as silicene and germanene, we study the particular impact that these moments have on graphene nanoengineered barriers with artificially enhanced spin-orbit coupling. We examine transmission properties of such barriers in the presence of a magnetic field. The orbital moments are found to manifest in transport characteristics through spin-dependent transmission and conductance, making them directly accessible in experiments. Moreover, the Zeeman-type effects appear without explicitly incorporating the Zeeman term in the models, i.e., by using minimal coupling and Peierls substitution in continuum and the tight-binding methods, respectively. We find that a quasiclassical view is able to explain all the observed phenomena.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000344915800009 Publication Date 2014-11-10
  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 5 Open Access
  Notes ; This work was supported by the Ministry of Education, Science and Technological Development (Serbia), and the Fonds Wetenschappelijk Onderzoek (Belgium). ; Approved Most recent IF: 3.836; 2014 IF: 3.736
  Call Number UA @ lucian @ c:irua:122141 Serial 2497
Permanent link to this record
 

 
Author Verberck, B.; Nikolaev, A.V.; Michel, K.H.
  Title Orientational charge density waves and the metal-insulator transition in polymerized KC60 Type A1 Journal article
  Year 2005 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 71 Issue 16 Pages 165117-11
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract A theoretical model is presented for the description of the metal-insulator transition which accompanies the structural phase transition at T approximate to 50 K in polymerized KC60. The model involves orientational charge density waves (along the C-60 polymer chains) which were introduced previously for a description of the structural phase transition. A satisfactory qualitative and quantitative understanding is obtained when the three-dimensionality of the crystal and the presence of the K+ counterions is properly taken into account.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000228763100035 Publication Date 2005-04-27
  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 1 Open Access
  Notes Approved Most recent IF: 3.836; 2005 IF: 3.185
  Call Number UA @ lucian @ c:irua:104076 Serial 2514
Permanent link to this record
 

 
Author Verberck, B.
  Title Orientational properties of C70 and C80 fullerenes in carbon nanotubes Type A1 Journal article
  Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 83 Issue 4 Pages 045405-045405,8
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract We present energy calculations of a C80 molecule with D5d symmetry encapsulated in a carbon nanotube. The approximation of a continuous tube rather than a rolled-up graphene sheet, justified by comparison with atomistic calculations, allows an expansion of the energy field into symmetry-adapted rotator functions. For a given tube radius R, we observe a strong dependence of the interaction energy on the molecular tilt angle and on the molecules lateral position in the tube. We observe a transition from on-axis lying orientations to tilted orientations at R1≈6.95 Å and a subsequent transition to standing orientations at R2≈7.6 Å. For tube radii larger than R3≈8.0 Å, the molecule starts to occupy off-axis positions and assumes a lying orientation. Results are compared to the case of C70 molecules, with D5h symmetry. Our findings are consistent with recent high-resolution transmission electron microscopy measurements and are relevant for the design of new materials with tunable electronic properties.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000286770600010 Publication Date 2011-01-20
  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 ; The author gratefully acknowledges discussions with A. V. Nikolaev and K. H. Michel. This work was financially supported by the Research Foundation-Flanders (FWO-Vl). ; Approved Most recent IF: 3.836; 2011 IF: 3.691
  Call Number UA @ lucian @ c:irua:88911 Serial 2520
Permanent link to this record
 

 
Author Vodolazov, D.Y.; Peeters, F.M.
  Title Origin of the hysteresis of the current voltage characteristics of superconducting microbridges near the critical temperature Type A1 Journal article
  Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 84 Issue 9 Pages 094511
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract The current voltage (IV) characteristics of short [with length L less than or similar to xi(T)] and long [L >> xi(T)] microbridges are theoretically investigated near the critical temperature of the superconductor. Calculations are made in the nonlocal (local) limit when the inelastic relaxation length due to electron-phonon interactions L(in) = (D tau(in))(1/2) is larger (smaller) than the temperature-dependent coherence length xi(T) (D is the diffusion coefficient, tau(in) is the inelastic relaxation time of the quasiparticle distribution function). We find that, in both limits, the origin of the hysteresis in the IV characteristics is mainly connected with the large time scale over which the magnitude of the order parameter varies in comparison with the time-scale variation of the superconducting phase difference across the microbridge in the resistive state. In the nonlocal limit, the time-averaged heating and cooling of quasiparticles are found in different areas of the microbridge, which are driven, respectively, by oscillations of the order parameter and the electric field. We show that, by introducing an additional term in the time-dependent Ginzburg-Landau equation, it is possible to take into account the cooling effect in the local limit too.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000294920900009 Publication Date 2011-09-14
  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 7 Open Access
  Notes ; This work was supported by the Russian Foundation for Basic Research, Russian Agency of Education under the Federal Target Programme“Scientific and educational personnel of innovative Russia in 2009-2013,” the Flemish Science Foundation (FWO-Vl), and the Belgian Science Policy (IAP). ; Approved Most recent IF: 3.836; 2011 IF: 3.691
  Call Number UA @ lucian @ c:irua:105573 Serial 2527
Permanent link to this record
 

 
Author Szaszko-Bogar, V.; Peeters, F.M.; Foeldi, P.
  Title Oscillating spin-orbit interaction in two-dimensional superlattices : sharp transmission resonances and time-dependent spin-polarized currents Type A1 Journal article
  Year 2015 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 91 Issue 91 Pages 235311
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract We consider ballistic transport through a lateral, two-dimensional superlattice with experimentally realizable, sinusoidally oscillating, Rashba-type spin-orbit interaction (SOI). The periodic structure of the rectangular lattice produces a spin-dependent miniband structure for static SOI. Using Floquet theory, transmission peaks are shown to appear in themini-bandgaps as a consequence of the additional, time-dependent SOI. A detailed analysis shows that this effect is due to the generation of harmonics of the driving frequency, via which, e.g., resonances that cannot be excited in the case of static SOI become available. Additionally, the transmitted current shows space-and time-dependent partial spin polarization, in other words, polarization waves propagate through the superlattice.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000355956500003 Publication Date 2015-06-10
  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 10 Open Access
  Notes ; This work was partially supported by the European Union and the European Social Fund through Projects No. TAMOP-4.2.2.C-11/1/KONV-2012-0010 and No. TAMOP-4.2.2.A-11/1/KONV-2012-0060, and by the Hungarian Scientific Research Fund (OTKA) under Contracts No. T81364 and No. 116688. The ELI-ALPS Project (GOP-1.1.1-12/B-2012-0001) is supported by the European Union and cofinanced by the European Regional Development Fund. ; Approved Most recent IF: 3.836; 2015 IF: 3.736
  Call Number c:irua:126432 Serial 2534
Permanent link to this record
 

 
Author Scarrozza, M.; Pourtois, G.; Houssa, M.; Heyns, M.; Stesmans, A.
  Title Oxidation of the GaAs(001) surface : insights from first-principles calculations Type A1 Journal article
  Year 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 85 Issue 19 Pages 195307-195307,8
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
  Abstract We performed a detailed investigation of the oxidation of the technologically relevant GaAs(001)-beta 2(2x4) surface via density functional calculations. The purpose is to gain insights on the atomistic mechanisms and local bondings that underlie the degradation of the surface properties once exposed to oxygen. The study comprises the adsorption of single O atoms, through the sampling of several adsorption sites, and the subsequent formation of the O adsorbate at increasing coverage by taking into account multiple-atom adsorption. Based on the evaluation of the energetics and the structural properties of the atomistic models generated, the results here reported delineate a consistent picture of the initial stage of the surface oxidation: (i) at low coverage, in the limit of single O insertions, oxygen is incorporated on the surface forming a twofold-bridging Ga-O-As bond; (ii) at increasing coverage, as multiple O atoms are involved, this is accompanied by the formation of a threefold-coordinated bond (with two Ga and one As atoms); (iii) the latter has important implications regarding the electronic properties of the adsorbate since this O bonding may result in the formation of As dangling bonds. Moreover, a clear trend of increased energy gain for the incorporation of neighboring O atoms compared to single O insertions indicates that the formation of oxide clusters is favored over a regime of uniform oxidation. Our findings provide a detailed description of the O bonding and stress the importance of modeling the adsorption of multiple O atoms for an accurate description of the surface oxidation.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000303755700006 Publication Date 2012-05-08
  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 15 Open Access
  Notes Approved Most recent IF: 3.836; 2012 IF: 3.767
  Call Number UA @ lucian @ c:irua:99122 Serial 2538
Permanent link to this record
 

 
Author Berdiyorov, G.R.; Milošević, M.V.; Savel'ev, S.; Kusmartsev, F.; Peeters, F.M.
  Title Parametric amplification of vortex-antivortex pair generation in a Josephson junction Type A1 Journal article
  Year 2014 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
  Volume 90 Issue 13 Pages 134505
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Using advanced three-dimensional simulations, we show that an Abrikosov vortex, trapped inside a cavity perpendicular to an artificial Josephson junction, can serve as a very efficient source for generation of Josephson vortex-antivortex pairs in the presence of the applied electric current. In such a case, the nucleation rate of the pairs can be tuned in a broad range by an out-of-plane ac magnetic field in a broad range of frequencies. This parametrically amplified vortex-antivortex nucleation can be considered as a macroscopic analog of the dynamic Casimir effect, where fluxon pairs mimic the photons and the ac magnetic field plays the role of the oscillating mirrors. The emerging vortex pairs in our system can be detected by the pronounced features in the measured voltage characteristics, or through the emitted electromagnetic radiation, and exhibit resonant dynamics with respect to the frequency of the applied magnetic field. Reported tunability of the Josephson oscillations can be useful for developing high-frequency emission devices.
  Address
  Corporate Author Thesis
  Publisher Place of Publication (down) Editor
  Language Wos 000344025100003 Publication Date 2014-10-06
  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 22 Open Access
  Notes ; This work was supported by the Flemish Science Foundation (FWO-VI) and the Leverhulme Trust. G.R.B. acknowledges support from a EU-Marie Curie individual grant (Grant No. 253057) ; Approved Most recent IF: 3.836; 2014 IF: 3.736
  Call Number UA @ lucian @ c:irua:121176 Serial 2553
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print

Save Citations:
Export Records: