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Author | Leliaert, J.; Dvornik, M.; Mulkers, J.; De Clercq, J.; Milošević, M.V.; Van Waeyenberge, B. | ||||
Title | Fast micromagnetic simulations on GPU-recent advances made with mumax3 | Type | A1 Journal article | ||
Year | 2018 | Publication | Journal of physics: D: applied physics | Abbreviated Journal | J Phys D Appl Phys |
Volume | 51 | Issue | 12 | Pages | 123002 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | In the last twenty years, numerical modeling has become an indispensable part of magnetism research. It has become a standard tool for both the exploration of new systems and for the interpretation of experimental data. In the last five years, the capabilities of micromagnetic modeling have dramatically increased due to the deployment of graphical processing units (GPU), which have sped up calculations to a factor of 200. This has enabled many studies which were previously unfeasible. In this topical review, we give an overview of this modeling approach and show how it has contributed to the forefront of current magnetism research. | ||||
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Corporate Author | Thesis | ||||
Publisher | Iop publishing ltd | Place of Publication | Bristol | Editor | |
Language | Wos | 000425774100001 | Publication Date | 2018-01-29 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0022-3727 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.588 | Times cited | 65 | Open Access | |
Notes | ; This work was supported by the Fonds Wetenschappelijk Onderzoek (FWO-Vlaanderen) through Project No. G098917N. JL is supported by the Ghent University Special Research Fund (BOF postdoctoral fellowship). We gratefully acknowledge the support of the NVIDIA Corporation with the donation of a Titan Xp GPU used for this research. ; | Approved | Most recent IF: 2.588 | ||
Call Number | UA @ lucian @ c:irua:149852UA @ admin @ c:irua:149852 | Serial | 4934 | ||
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Author | Jelić, Ž. | ||||
Title | Emergent vortex phenomena in spatially and temporally modulated superconducting condensates | Type | Doctoral thesis | ||
Year | 2018 | Publication | Abbreviated Journal | ||
Volume | Issue | Pages | 181 p. | ||
Keywords | Doctoral thesis; Engineering sciences. Technology; Condensed Matter Theory (CMT) | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | Publication Date | |||
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | ISBN | Additional Links | UA library record | ||
Impact Factor | Times cited | Open Access | |||
Notes | Approved | Most recent IF: NA | |||
Call Number | UA @ admin @ c:irua:149394 | Serial | 5209 | ||
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Author | Peymanirad, F.; Singh, S.K.; Ghorbanfekr-Kalashami, H.; Novoselov, K.S.; Peeters, F.M.; Neek-Amal, M. | ||||
Title | Thermal activated rotation of graphene flake on graphene | Type | A1 Journal article | ||
Year | 2017 | Publication | 2D materials | Abbreviated Journal | 2D Mater |
Volume | 4 | Issue | 2 | Pages | 025015 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | The self rotation of a graphene flake over graphite is controlled by the size, initial misalignment and temperature. Using both ab initio calculations and molecular dynamics simulations, we investigate annealing effects on the self rotation of a graphene flake on a graphene substrate. The energy barriers for rotation and drift of a graphene flake over graphene is found to be smaller than 25 meV/atom which is comparable to thermal energy. We found that small flakes (of about similar to 4 nm) are more sensitive to temperature and initial misorientation angles than larger one (beyond 10 nm). The initial stacking configuration of the flake is found to be important for its dynamics and time evolution of misalignment. Large flakes, which are initially in the AA-or AB-stacking state with small misorientation angle, rotate and end up in the AB-stacking configuration. However small flakes can they stay in an incommensurate state specially when the initial misorientation angle is larger than 2 degrees. Our results are in agreement with recent experiments. | ||||
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Corporate Author | Thesis | ||||
Publisher | IOP Publishing | Place of Publication | Bristol | Editor | |
Language | Wos | 000424399600005 | Publication Date | 2017-02-02 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2053-1583 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.937 | Times cited | 16 | Open Access | |
Notes | ; We would like to acknowledge Annalisa Fasolino and MM van Wijk for providing us with the implemented parameters of REBO-KC [5] in LAMMPS. This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation. ; | Approved | Most recent IF: 6.937 | ||
Call Number | UA @ lucian @ c:irua:149364 | Serial | 4984 | ||
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Author | Lombardo, J.; Jelić, Ž.L.; Baumans, X.D.A.; Scheerder, J.E.; Nacenta, J.P.; Moshchalkov, V.V.; Van de Vondel, J.; Kramer, R.B.G.; Milošević, M.V.; Silhanek, A.V. | ||||
Title | In situ tailoring of superconducting junctions via electro-annealing | Type | A1 Journal article | ||
Year | 2018 | Publication | Nanoscale | Abbreviated Journal | Nanoscale |
Volume | 10 | Issue | 4 | Pages | 1987-1996 |
Keywords | A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) | ||||
Abstract | We demonstrate the in situ engineering of superconducting nanocircuitry by targeted modulation of material properties through high applied current densities. We show that the sequential repetition of such customized electro-annealing in a niobium (Nb) nanoconstriction can broadly tune the superconducting critical temperature T-c and the normal-state resistance R-n in the targeted area. Once a sizable R-n is reached, clear magneto-resistance oscillations are detected along with a Fraunhofer-like field dependence of the critical current, indicating the formation of a weak link but with further adjustable characteristics. Advanced Ginzburg-Landau simulations fully corroborate this picture, employing the detailed parametrization from the electrical characterization and high resolution electron microscope images of the region within the constriction where the material has undergone amorphization by electro-annealing. | ||||
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Publisher | Place of Publication | Cambridge | Editor | ||
Language | Wos | 000423355300049 | Publication Date | 2017-12-29 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2040-3364 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 7.367 | Times cited | 23 | Open Access | |
Notes | ; The authors thank the Fonds de la Recherche Scientifique – FNRS, the ARC grant 13/18-08 for Concerted Research Actions, financed by the French Community of Belgium (Wallonia-Brussels Federation), the Research Foundation – Flanders (FWO-Vlaanderen) and the COST action NanoCoHybri (CA16218). The work is also suppported by Methusalem Funding by the Flemish Government. J. Lombardo acknowledges support from F. R. S.-FNRS (FRIA Research Fellowship). The LANEF framework (ANR-10-LABX-51-01) and the Nanoscience Foundation are acknowledged for their support with mutualized infrastructure. The work of A. V. Silhanek is partially supported by PDR T.0106.16 of the F. R. S.-FNRS. The authors thank the ULg Microscopy facility CAREM for part of the SEM investigations. ; | Approved | Most recent IF: 7.367 | ||
Call Number | UA @ lucian @ c:irua:149315UA @ admin @ c:irua:149315 | Serial | 4937 | ||
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Author | Aierken, Y.; Sevik, C.; Gulseren, O.; Peeters, F.M.; Çakir, D. | ||||
Title | MXenes/graphene heterostructures for Li battery applications : a first principles study | Type | A1 Journal article | ||
Year | 2018 | Publication | Journal of materials chemistry A : materials for energy and sustainability | Abbreviated Journal | J Mater Chem A |
Volume | 6 | Issue | 5 | Pages | 2337-2345 |
Keywords | A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) | ||||
Abstract | MXenes are the newest class of two-dimensional (2D) materials, and they offer great potential in a wide range of applications including electronic devices, sensors, and thermoelectric and energy storage materials. In this work, we combined the outstanding electrical conductivity, that is essential for battery applications, of graphene with MXene monolayers (M2CX2 where M = Sc, Ti, V and X = OH, O) to explore its potential in Li battery applications. Through first principles calculations, we determined the stable stacking configurations of M2CX2/graphene bilayer heterostructures and their Li atom intercalation by calculating the Li binding energy, diffusion barrier and voltage. We found that: (1) for the ground state stacking, the interlayer binding is strong, yet the interlayer friction is small; (2) Li binds more strongly to the O-terminated monolayer, bilayer and heterostructure MXene systems when compared with the OHterminated MXenes due to the H+ induced repulsion to the Li atoms. The binding energy of Li decreases as the Li concentration increases due to enhanced repulsive interaction between the positively charged Li ions; (3) Ti2CO2/graphene and V2CO2/graphene heterostructures exhibit large Li atom binding energies making them the most promising candidates for battery applications. When fully loaded with Li atoms, the binding energy is -1.43 eV per Li atom and -1.78 eV per Li atom for Ti2CO2/graphene and V2CO2/graphene, respectively. These two heterostructures exhibit a nice compromise between storage capacity and kinetics. For example, the diffusion barrier of Li in Ti2CO2/graphene is around 0.3 eV which is comparable to that of graphite. Additionally, the calculated average voltages are 1.49 V and 1.93 V for Ti2CO2/graphene and V2CO2/graphene structures, respectively; (4) a small change in the in-plane lattice parameters (<1%), interatomic bond lengths and interlayer distances (<0.5 angstrom) proves the stability of the heterostructures against Li intercalation, and the impending phase separation into constituent layers and capacity fading during charge-discharge cycles in real battery applications; (5) as compared to bare M2CX2 bilayers, M2CX2/graphene heterostructures have lower molecular mass, offering high storage capacity; (6) the presence of graphene ensures good electrical conductivity that is essential for battery applications. Given these advantages, Ti2CO2/graphene and V2CO2/graphene heterostructures are predicted to be promising for lithium-ion battery applications. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Cambridge | Editor | ||
Language | Wos | 000423981200049 | Publication Date | 2018-01-02 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2050-7488; 2050-7496 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 8.867 | Times cited | 131 | Open Access | |
Notes | ; This work was supported by the bilateral project between the Scientific and Technological Research Council of Turkey (TUBITAK) and FWO-Flanders, Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by the TUBITAK ULAKBIM, High Performance and Grid Computing Center (TRGrid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. We acknowledge the support from the TUBITAK (Grant No. 115F024 and 116F080). Part of this work was supported by the BAGEP Award of the Science Academy. ; | Approved | Most recent IF: 8.867 | ||
Call Number | UA @ lucian @ c:irua:149265UA @ admin @ c:irua:149265 | Serial | 4945 | ||
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Author | Berdiyorov, G.R.; Milošević, M.V.; Kusmartsev, F.; Peeters, F.M.; Savel'ev, S. | ||||
Title | Josephson vortex loops in nanostructured Josephson junctions | Type | A1 Journal article | ||
Year | 2018 | Publication | Scientific reports | Abbreviated Journal | Sci Rep-Uk |
Volume | 8 | Issue | 8 | Pages | 2733 |
Keywords | A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) | ||||
Abstract | Linked and knotted vortex loops have recently received a revival of interest. Such three-dimensional topological entities have been observed in both classical-and super-fluids, as well as in optical systems. In superconductors, they remained obscure due to their instability against collapse – unless supported by inhomogeneous magnetic field. Here we reveal a new kind of vortex matter in superconductors -the Josephson vortex loops – formed and stabilized in planar junctions or layered superconductors as a result of nontrivial cutting and recombination of Josephson vortices around the barriers for their motion. Engineering latter barriers opens broad perspectives on loop manipulation and control of other possible knotted/linked/entangled vortex topologies in nanostructured superconductors. In the context of Josephson devices proposed to date, the high-frequency excitations of the Josephson loops can be utilized in future design of powerful emitters, tunable filters and waveguides of high-frequency electromagnetic radiation, thereby pushing forward the much needed Terahertz technology. | ||||
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Corporate Author | Thesis | ||||
Publisher | Nature Publishing Group | Place of Publication | London | Editor | |
Language | Wos | 000424630400046 | Publication Date | 2018-02-05 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2045-2322 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.259 | Times cited | 10 | Open Access | |
Notes | ; This work was supported by EU Marie-Curie program (project No: 253057), Special Research Funds of the University of Antwerp (BOF-UA), and by the Research Foundation – Flanders (FWO). ; | Approved | Most recent IF: 4.259 | ||
Call Number | UA @ lucian @ c:irua:149262UA @ admin @ c:irua:149262 | Serial | 4940 | ||
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Author | Li, L.L.; Peeters, F.M. | ||||
Title | Quantum transport in defective phosphorene nanoribbons : effects of atomic vacancies | Type | A1 Journal article | ||
Year | 2018 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
Volume | 97 | Issue | 7 | Pages | 075414 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Defects are almost inevitably present in realistic materials and defective materials are expected to exhibit very different properties than their nondefective (perfect) counterparts. Here, using a combination of the tight-binding approach and the scattering matrix formalism, we investigate the electronic transport properties of defective phosphorene nanoribbons (PNRs) containing atomic vacancies. We find that for both armchair PNRs (APNRs) and zigzag PNRs (ZPNRs), single vacancies can create quasilocalized states, which can affect their conductance. With increasing vacancy concentration, three different transport regimes are identified: ballistic, diffusive, and Anderson localized ones. In particular, ZPNRs that are known to be metallic due to the presence of edge states become semiconducting: edge conductance vanishes and transport gap appears due to Anderson localization. Moreover, we find that for a fixed vacancy concentration, both APNRs and ZPNRs of narrower width and/or longer length are more sensitive to vacancy disorder than their wider and/or shorter counterparts, and that for the same ribbon length and width, ZPNRs are more sensitive to vacancy disorder than APNRs. | ||||
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Publisher | American Physical Society | Place of Publication | New York, N.Y | Editor | |
Language | Wos | 000424901800006 | Publication Date | 2018-02-13 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2469-9969; 2469-9950 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 30 | Open Access | |
Notes | ; This work was financially supported by the Flemish Science Foundation (FWO-Vl), the FLAG-ERA TRANS 2D TMD, and by the Chinese Academy of Sciences (CAS). ; | Approved | Most recent IF: 3.836 | ||
Call Number | UA @ lucian @ c:irua:149255UA @ admin @ c:irua:149255 | Serial | 4946 | ||
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Author | Schulenborg, J.; Di Marco, A.; Vanherck, J.; Wegewijs, M.R.; Splettstoesser, J. | ||||
Title | Thermoelectrics of interacting nanosystems-exploiting superselection instead of time-reversal symmetry | Type | A1 Journal article | ||
Year | 2017 | Publication | Entropy: an international and interdisciplinary journal of entropy and information studies | Abbreviated Journal | Entropy-Switz |
Volume | 19 | Issue | 12 | Pages | 668 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | <script type='text/javascript'>document.write(unpmarked('Thermoelectric transport is traditionally analyzed using relations imposed by time-reversal symmetry, ranging from Onsager\u0027s results to fluctuation relations in counting statistics. In this paper, we show that a recently discovered duality relation for fermionic systems-deriving from the fundamental fermion-parity superselection principle of quantum many-particle systems-provides new insights into thermoelectric transport. Using a master equation, we analyze the stationary charge and heat currents through a weakly coupled, but strongly interacting single-level quantum dot subject to electrical and thermal bias. In linear transport, the fermion-parity duality shows that features of thermoelectric response coefficients are actually dominated by the average and fluctuations of the charge in a dual quantum dot system, governed by attractive instead of repulsive electron-electron interaction. In the nonlinear regime, the duality furthermore relates most transport coefficients to much better understood equilibrium quantities. Finally, we naturally identify the fermion-parity as the part of the Coulomb interaction relevant for both the linear and nonlinear Fourier heat. Altogether, our findings hence reveal that next to time-reversal, the duality imposes equally important symmetry restrictions on thermoelectric transport. As such, it is also expected to simplify computations and clarify the physical understanding for more complex systems than the simplest relevant interacting nanostructure model studied here.')); | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000419007900037 | Publication Date | 2017-12-06 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1099-4300 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 1.821 | Times cited | 3 | Open Access | |
Notes | ; We thank Rafael Sanchez for useful comments on the manuscript. We acknowledge funding from the Knut and Alice Wallenberg foundation through their Academy Fellows program (J.Sp. and A.D.M.), from the Swedish VR (J.Sp. and J.Sc.), from the Erasmus Mundus program (J.V.), and from the DFG project SCHO 641/7-1 (M.R.W.). ; | Approved | Most recent IF: 1.821 | ||
Call Number | UA @ lucian @ c:irua:148548 | Serial | 4900 | ||
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Author | Dutta, S.; Zografos, O.; Gurunarayanan, S.; Radu, I.; Sorée, B.; Catthoor, F.; Naeemi, A. | ||||
Title | Proposal for nanoscale cascaded plasmonic majority gates for non-Boolean computation | Type | A1 Journal article | ||
Year | 2017 | Publication | Scientific reports | Abbreviated Journal | Sci Rep-Uk |
Volume | 7 | Issue | Pages | 17866 | |
Keywords | A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) | ||||
Abstract | <script type='text/javascript'>document.write(unpmarked('Surface-plasmon-polariton waves propagating at the interface between a metal and a dielectric, hold the key to future high-bandwidth, dense on-chip integrated logic circuits overcoming the diffraction limitation of photonics. While recent advances in plasmonic logic have witnessed the demonstration of basic and universal logic gates, these CMOS oriented digital logic gates cannot fully utilize the expressive power of this novel technology. Here, we aim at unraveling the true potential of plasmonics by exploiting an enhanced native functionality – the majority voter. Contrary to the state-of-the-art plasmonic logic devices, we use the phase of the wave instead of the intensity as the state or computational variable. We propose and demonstrate, via numerical simulations, a comprehensive scheme for building a nanoscale cascadable plasmonic majority logic gate along with a novel referencing scheme that can directly translate the information encoded in the amplitude and phase of the wave into electric field intensity at the output. Our MIM-based 3-input majority gate displays a highly improved overall area of only 0.636 mu m(2) for a single-stage compared with previous works on plasmonic logic. The proposed device demonstrates non-Boolean computational capability and can find direct utility in highly parallel real-time signal processing applications like pattern recognition.')); | ||||
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Publisher | Nature Publishing Group | Place of Publication | London | Editor | |
Language | Wos | 000418359600116 | Publication Date | 2017-12-13 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2045-2322 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.259 | Times cited | 2 | Open Access | |
Notes | ; ; | Approved | Most recent IF: 4.259 | ||
Call Number | UA @ lucian @ c:irua:148514 | Serial | 4891 | ||
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Author | Andrikopoulos, D.; Sorée, B. | ||||
Title | Skyrmion electrical detection with the use of three-dimensional Topological Insulators/Ferromagnetic bilayers | Type | A1 Journal article | ||
Year | 2017 | Publication | Scientific reports | Abbreviated Journal | Sci Rep-Uk |
Volume | 7 | Issue | Pages | 17871 | |
Keywords | A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) | ||||
Abstract | <script type='text/javascript'>document.write(unpmarked('The effect of the magnetic skyrmion texture on the electronic transport properties of the Tl surface state coupled to a thin-film FM is numerically investigated. It is shown that both Bloch (vortex) and Neel (hedgehog) skyrmion textures induce additional scattering on top of a homogeneous background FM texture which can modify the conductance of the system. The change in conductance depends on several factors including the skyrmion size, the dimensions of the FM and the exchange interaction strength. For the Neel skyrmion, the result of the interaction strongly depends on the skyrmion number N-sk and the skyrmion helicity h. For both skyrmion types, significant change of the resistance can be achieved, which is in the order of k Omega.')); | ||||
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Publisher | Nature Publishing Group | Place of Publication | London | Editor | |
Language | Wos | 000418359600121 | Publication Date | 2017-12-13 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2045-2322 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.259 | Times cited | 3 | Open Access | |
Notes | ; ; | Approved | Most recent IF: 4.259 | ||
Call Number | UA @ lucian @ c:irua:148513 | Serial | 4896 | ||
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Author | Conti, S.; Perali, A.; Peeters, F.M.; Neilson, D. | ||||
Title | Multicomponent electron-hole superfluidity and the BCS-BEC crossover in double bilayer graphene | Type | A1 Journal article | ||
Year | 2017 | Publication | Physical review letters | Abbreviated Journal | Phys Rev Lett |
Volume | 119 | Issue | 25 | Pages | 257002 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | <script type='text/javascript'>document.write(unpmarked('Superfluidity in coupled electron-hole sheets of bilayer graphene is predicted here to be multicomponent because of the conduction and valence bands. We investigate the superfluid crossover properties as functions of the tunable carrier densities and the tunable energy band gap Eg. For small band gaps there is a significant boost in the two superfluid gaps, but the interaction-driven excitations from the valence to the conduction band can weaken the superfluidity, even blocking the system from entering the Bose-Einstein condensate (BEC) regime at low densities. At a given larger density, a band gap E-g similar to 80-120 meV can carry the system into the strong-pairing multiband BCS-BEC crossover regime, the optimal range for realization of high-Tc superfluidity.')); | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | New York, N.Y. | Editor | ||
Language | Wos | 000418619100017 | Publication Date | 2017-12-22 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0031-9007 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 8.462 | Times cited | 18 | Open Access | |
Notes | ; We thank Mohammad Zarenia for useful discussions. Part of this work was supported by FWO-VI (Flemish Science Foundation) and the Methusalem program. ; | Approved | Most recent IF: 8.462 | ||
Call Number | UA @ lucian @ c:irua:148509 | Serial | 4885 | ||
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Author | Zhang, L.-F.; Covaci, L.; Milošević, M.V. | ||||
Title | Topological phase transitions in small mesoscopic chiral p-wave superconductors | Type | A1 Journal article | ||
Year | 2017 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
Volume | 96 | Issue | 22 | Pages | 224512 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | <script type='text/javascript'>document.write(unpmarked('Spin-triplet chiral p-wave superconductivity is typically described by a two-component order parameter, and as such is prone to unique emergent effects when compared to the standard single-component superconductors. Here we present the equilibrium phase diagram for small mesoscopic chiral p-wave superconducting disks in the presence of magnetic field, obtained by solving the microscopic Bogoliubov-de Gennes equations self-consistently. In the ultrasmall limit, the cylindrically symmetric giant-vortex states form the ground state of the system. However, with increasing sample size, the cylindrical symmetry is broken as the two components of the order parameter segregate into domains, and the number of fragmented domain walls between them characterizes the resulting states. Such domain walls are topological defects unique for the p-wave order, and constitute a dominant phase in the mesoscopic regime. Moreover, we find two possible types of domain walls, identified by their chirality-dependent interaction with the edge states.')); | ||||
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Corporate Author | Thesis | ||||
Publisher | American Physical Society | Place of Publication | New York, N.Y | Editor | |
Language | Wos | 000418653500012 | Publication Date | 2017-12-26 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2469-9969; 2469-9950 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 18 | Open Access | |
Notes | ; This work was supported by the Research Foundation Flanders (FWO-Vlaanderen) and the Special Research Funds of the University of Antwerp. ; | Approved | Most recent IF: 3.836 | ||
Call Number | UA @ lucian @ c:irua:148504 | Serial | 4901 | ||
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Author | Kundys, D.; Van Duppen, B.; Marshall, O.P.; Rodriguez, F.; Torre, I.; Tomadin, A.; Polini, M.; Grigorenko, A.N. | ||||
Title | Nonlinear light mixing by graphene plasmons | Type | A1 Journal article | ||
Year | 2018 | Publication | Nano letters | Abbreviated Journal | Nano Lett |
Volume | 18 | Issue | 1 | Pages | 282-287 |
Keywords | A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) | ||||
Abstract | <script type='text/javascript'>document.write(unpmarked('Graphene is known to possess strong optical nonlinearity which turned out to be suitable for creation of efficient saturable absorbers in mode locked fiber lasers. Nonlinear response of graphene can be further enhanced by the presence of graphene plasmons. Here, we report a novel nonlinear effect observed in nanostructured graphene which comes about due to excitation of graphene plasmons. We experimentally detect and theoretically explain enhanced mixing of near-infrared and mid-infrared light in arrays of graphene nanoribbons. Strong compression of light by graphene plasmons implies that the described effect of light mixing is nonlocal in nature and orders of magnitude larger than the conventional local graphene nonlinearity. Both second and third order nonlinear effects were observed in our experiments with the recalculated third-order nonlinearity coefficient reaching values of 4.5 x 10(-6) esu. The suggested effect could be used in variety of applications including nonlinear light modulators, light multiplexers, light logic, and sensing devices.')); | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Washington | Editor | ||
Language | Wos | 000420000000039 | Publication Date | 2017-12-11 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1530-6984 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 12.712 | Times cited | 12 | Open Access | |
Notes | ; This work was supported by the European Union's Horizon 2020 research and innovation programme under Grant Agreement 696656 “GrapheneCorel”, Bluestone Global Technology, and Fondazione Istituto Italiano di Tecnologia. B.V.D. is supported by a postdoctoral fellowship granted by FWO-Vl and wishes to thank Scuola Normale Superiore (Pisa, Italy) for their hospitality during the final stages of preparation of this work. ; | Approved | Most recent IF: 12.712 | ||
Call Number | UA @ lucian @ c:irua:148457UA @ admin @ c:irua:148457 | Serial | 4887 | ||
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Author | Bekaert, J.; Aperis, A.; Partoens, B.; Oppeneer, P.M.; Milošević, M.V. | ||||
Title | Advanced first-principles theory of superconductivity including both lattice vibrations and spin fluctuations : the case of FeB4 | Type | A1 Journal article | ||
Year | 2018 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
Volume | 97 | Issue | 1 | Pages | 014503 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | <script type='text/javascript'>document.write(unpmarked('We present an advanced method to study spin fluctuations in superconductors quantitatively and entirely from first principles. This method can be generally applied to materials where electron-phonon coupling and spin fluctuations coexist. We employ it here to examine the recently synthesized superconductor iron tetraboride (FeB4) with experimental T-c similar to 2.4 K [H. Gou et al., Phys. Rev. Lett, 111, 157002 (2013)]. We prove that FeB4 is particularly prone to ferromagnetic spin fluctuations due to the presence of iron, resulting in a large Stoner interaction strength, I = 1.5 eV, as calculated from first principles. The other important factor is its Fermi surface that consists of three separate sheets, among which two are nested ellipsoids. The resulting susceptibility has a ferromagnetic peak around q = 0, from which we calculated the repulsive interaction between Cooper pair electrons using the random phase approximation. Subsequently, we combined the electron-phonon interaction calculated from first principles with the spin fluctuation interaction in fully anisotropic Eliashberg theory calculations. We show that the resulting superconducting gap spectrum is conventional, yet very strongly depleted due to coupling to the spin fluctuations. The critical temperature decreases from T-c = 41 K, if they are not taken into account, to T-c = 1.7 K, in good agreement with the experimental value.')); | ||||
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Corporate Author | Thesis | ||||
Publisher | American Physical Society | Place of Publication | New York, N.Y | Editor | |
Language | Wos | 000419229100004 | Publication Date | 2018-01-04 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2469-9969; 2469-9950 | 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 TOPBOF-UAntwerp, Research Foundation Flanders (FWO), the Swedish Research Council (VR), and the Rontgen-Angstrom Cluster. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Research Foundation Flanders (FWO) and the Flemish Government-department EWI. Anisotropic Eliashberg theory calculations were supported through the Swedish National Infrastructure for Computing (SNIC). ; | Approved | Most recent IF: 3.836 | ||
Call Number | UA @ lucian @ c:irua:148447UA @ admin @ c:irua:148447 | Serial | 4866 | ||
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Author | Lane, T.L.M.; Andelkovic, M.; Wallbank, J.R.; Covaci, L.; Peeters, F.M.; Fal'ko, V.I. | ||||
Title | Ballistic electron channels including weakly protected topological states in delaminated bilayer graphene | Type | A1 Journal article | ||
Year | 2018 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
Volume | 97 | Issue | 4 | Pages | 045301 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | <script type='text/javascript'>document.write(unpmarked('We show that delaminations in bilayer graphene (BLG) with electrostatically induced interlayer symmetry can provide one with ballistic channels for electrons with energies inside the electrostatically induced BLG gap. These channels are formed by a combination of valley-polarized evanescent states propagating along the delamination edges (which persist in the presence of a strong magnetic field) and standing waves bouncing between them inside the delaminated region (in a strong magnetic field, these transform into Landau levels in the monolayers). For inverted stackings in BLGs on the left and right of the delamination (AB-2ML-BA or BA-2ML-AB, where 2ML indicates two decoupled monolayers of graphene), the lowest-energy ballistic channels are gapless, have linear dispersion, and appear to be weakly topologically protected. When BLG stackings on both sides of the delamination are the same (AB-2ML-AB or BA-2ML-BA), the lowest-energy ballistic channels are gapped, with a gap epsilon(g) scaling as epsilon(g) alpha W-1 with delamination width and epsilon(g) alpha delta(-1) with the on-layer energy difference in the delaminated part of the structure. Depending on the width, delaminations may also support several \u0022higher-energy\u0022 waveguide modes. Our results are based on both the analytical study of the wave matching of Dirac states and tight-binding model calculations, and we analyze in detail the dependence of the delamination spectrum on the electrostatic conditions in the structure, such as the vertical displacement field.')); | ||||
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Corporate Author | Thesis | ||||
Publisher | American Physical Society | Place of Publication | New York, N.Y | Editor | |
Language | Wos | 000419772200005 | Publication Date | 2018-01-11 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2469-9969; 2469-9950 | 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 funded by EPSRC via EPSRC Grand Engineering Chellenges Grant No. EP/N010345, the Manchester NOWNANO CDT EP/L-1548X, the Flemish Science Foundation (FWO-VI), the European Graphene Flagship project, ERC Synergy grant Hetero2D, and FLAG-ERA project TRANS2DTMD. The authors would like to acknowledge useful discussions with M. Zarenia, S. Slizovskiy, E. McCann, and K. Novesolov. ; | Approved | Most recent IF: 3.836 | ||
Call Number | UA @ lucian @ c:irua:148441UA @ admin @ c:irua:148441 | Serial | 4868 | ||
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Author | Jakovljevic, D.Z.; Grujic, M.M.; Tadic, M.Z.; Peeters, F.M. | ||||
Title | Helical edge states in silicene and germanene nanorings in perpendicular magnetic field | Type | A1 Journal article | ||
Year | 2018 | Publication | Journal of physics : condensed matter | Abbreviated Journal | J Phys-Condens Mat |
Volume | 30 | Issue | 3 | Pages | 035301 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | <script type='text/javascript'>document.write(unpmarked('Due to nonzero intrinsic spin-orbit interaction in buckled honeycomb crystal structures, silicene and germanene exhibit interesting topological properties, and are therefore candidates for the realization of the quantum spin Hall effect. We employ the Kane-Mele model to investigate the electron states in hexagonal silicene and germanene nanorings having either zigzag or armchair edges in the presence of a perpendicular magnetic field. We present results for the energy spectra as function of magnetic field, the electron density of the spin-up and spin-down states in the ring plane, and the calculation of the probability current density. The quantum spin Hall phase is found at the edges between the nontrivial topological phase in silicene and germanene and vacuum. We demonstrate that the helical edge states in zigzag silicene and germanene nanorings can be qualitatively well understood by means of classical magnetic moments. However, this is not the case for comparable-sized armchair nanorings, where the eigenfunctions spread throughout the ring. Finally, we note that the energy spectra of silicene and germanene nanorings are similar and that the differences between the two are mainly related to the difference in magnitude of the spin-orbit coupling.')); | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | London | Editor | ||
Language | Wos | 000418354400001 | Publication Date | 2017-11-30 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0953-8984 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.649 | Times cited | 4 | Open Access | |
Notes | ; This work was supported by Erasmus+ and the Serbian Ministry of Education, Science and Technological Development (Project No. III45003). ; | Approved | Most recent IF: 2.649 | ||
Call Number | UA @ lucian @ c:irua:148426UA @ admin @ c:irua:148426 | Serial | 4878 | ||
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Author | Leliaert, J.; Mulkers, J.; De Clercq, J.; Coene, A.; Dvornik, M.; Van Waeyenberge, B. | ||||
Title | Adaptively time stepping the stochastic Landau-Lifshitz-Gilbert equation at nonzero temperature: Implementation and validation in MuMax3 | Type | A1 Journal article | ||
Year | 2017 | Publication | AIP advances | Abbreviated Journal | Aip Adv |
Volume | 7 | Issue | 12 | Pages | 125010 |
Keywords | A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) | ||||
Abstract | Thermal fluctuations play an increasingly important role in micromagnetic research relevant for various biomedical and other technological applications. Until now, it was deemed necessary to use a time stepping algorithm with a fixed time step in order to perform micromagnetic simulations at nonzero temperatures. However, Berkov and Gorn have shown in [D. Berkov and N. Gorn, J. Phys.: Condens. Matter,14, L281, 2002] that the drift term which generally appears when solving stochastic differential equations can only influence the length of the magnetization. This quantity is however fixed in the case of the stochastic Landau-Lifshitz-Gilbert equation. In this paper, we exploit this fact to straightforwardly extend existing high order solvers with an adaptive time stepping algorithm. We implemented the presented methods in the freely available GPU-accelerated micromagnetic software package MuMax3 and used it to extensively validate the presented methods. Next to the advantage of having control over the error tolerance, we report a twenty fold speedup without a loss of accuracy, when using the presented methods as compared to the hereto best practice of using Heun’s solver with a small fixed time step. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000418492500010 | Publication Date | 2017-12-11 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2158-3226 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 1.568 | Times cited | 13 | Open Access | |
Notes | This work was supported by the Fonds Wetenschappelijk Onderzoek (FWO-Vlaanderen) through Project No. G098917N and a postdoctoral fellowship (A.C.). J. L. is supported by the Ghent University Special Research Fund (BOF postdoctoral fellowship). We gratefully acknowl- edge the support of NVIDIA Corporation with the donation of the Titan Xp GPU used for this research. | Approved | Most recent IF: 1.568 | ||
Call Number | CMT @ cmt @c:irua:147860 | Serial | 4799 | ||
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Author | Wang, Y.-L.; Glatz, A.; Kimmel, G.J.; Aranson, I.S.; Thoutam, L.R.; Xiao, Z.-L.; Berdiyorov, G.R.; Peeters, F.M.; Crabtree, G.W.; Kwok, W.-K. | ||||
Title | Parallel magnetic field suppresses dissipation in superconducting nanostrips | Type | A1 Journal article | ||
Year | 2017 | Publication | America | Abbreviated Journal | P Natl Acad Sci Usa |
Volume | 114 | Issue | 48 | Pages | E10274-E10280 |
Keywords | A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) | ||||
Abstract | <script type='text/javascript'>document.write(unpmarked('The motion of Abrikosov vortices in type-II superconductors results in a finite resistance in the presence of an applied electric current. Elimination or reduction of the resistance via immobilization of vortices is the \u0022holy grail\u0022 of superconductivity research. Common wisdom dictates that an increase in the magnetic field escalates the loss of energy since the number of vortices increases. Here we show that this is no longer true if the magnetic field and the current are applied parallel to each other. Our experimental studies on the resistive behavior of a superconducting Mo0.79Ge0.21 nanostrip reveal the emergence of a dissipative state with increasing magnetic field, followed by a pronounced resistance drop, signifying a reentrance to the superconducting state. Large-scale simulations of the 3D time-dependent Ginzburg-Landau model indicate that the intermediate resistive state is due to an unwinding of twisted vortices. When the magnetic field increases, this instability is suppressed due to a better accommodation of the vortex lattice to the pinning configuration. Our findings show that magnetic field and geometrical confinement can suppress the dissipation induced by vortex motion and thus radically improve the performance of superconducting materials.')); | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Washington, D.C. | Editor | ||
Language | Wos | 000416891600007 | Publication Date | 2017-11-13 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0027-8424; 1091-6490 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 9.661 | Times cited | 18 | Open Access | |
Notes | ; This work was supported by the US Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division. The simulation was supported by the Scientific Discovery through Advanced Computing program funded by US DOE, Office of Science, Advanced Scientific Computing Research and Basic Energy Science, Division of Materials Science and Engineering. L.R.T. and Z.-L.X. acknowledge support through National Science Foundation Grant DMR-1407175. Use of the Center for Nanoscale Materials, an Office of Science user facility, was supported by the DOE, Office of Science, Office of Basic Energy Sciences, under Contract DE-AC02-06CH11357. ; | Approved | Most recent IF: 9.661 | ||
Call Number | UA @ lucian @ c:irua:147697 | Serial | 4889 | ||
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Author | Stosic, D.; Ludermir, T.B.; Milošević, M.V. | ||||
Title | Pinning of magnetic skyrmions in a monolayer Co film on Pt(111) : Theoretical characterization and exemplified utilization | Type | A1 Journal article | ||
Year | 2017 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
Volume | 96 | Issue | 21 | Pages | 214403 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | <script type='text/javascript'>document.write(unpmarked('Magnetic skyrmions are nanoscale windings of the spin structure that can be observed in chiral magnets and hold promise for potential applications in storing or processing information. Pinning due to ever-present material imperfections crucially affects the mobility of skyrmions. Therefore, a proper understanding of how magnetic skyrmions pin to defects is necessary for the development and performance of spintronic devices. Here we present a fundamental analysis on the interactions of single skyrmions with atomic defects of distinctly different origins, in a Co monolayer on Pt, based on minimum-energy paths considerations and atomic-spin simulations. We first report the preferred pinning loci of the skyrmion as a function of its nominal size and the type of defect being considered, to further reveal the manipulation and \u0022breathing\u0022 of skyrmion core in the vicinity of a defect. We also show the behavior of skyrmions in the presence of an extended defect of particular geometry, that can lead to ratcheted skyrmion motion or a facilitated guidance on a defect \u0022trail.\u0022 We close the study with reflections on the expected thermal stability of the skyrmion against collapse on itself for a given nature of the defect, and discuss the applications where control of skyrmions by defects is of particular interest.')); | ||||
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Corporate Author | Thesis | ||||
Publisher | American Physical Society | Place of Publication | New York, N.Y | Editor | |
Language | Wos | 000416846900002 | Publication Date | 2017-12-01 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2469-9969; 2469-9950 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 52 | Open Access | |
Notes | ; This work was supported by the Research Foundation, Flanders (FWO-Vlaanderen) and Brazilian agency CNPq (Grants No. 442668/2014-7 and No. 140840/2016-8). ; | Approved | Most recent IF: 3.836 | ||
Call Number | UA @ lucian @ c:irua:147684 | Serial | 4890 | ||
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Author | Bekaert, J.; Bignardi, L.; Aperis, A.; van Abswoude, P.; Mattevi, C.; Gorovikov, S.; Petaccia, L.; Goldoni, A.; Partoens, B.; Oppeneer, P.M.; Peeters, F.M.; Milošević, M.V.; Rudolf, P.; Cepek, C. | ||||
Title | Free surfaces recast superconductivity in few-monolayer MgB2 : combined first-principles and ARPES demonstration | Type | A1 Journal article | ||
Year | 2017 | Publication | Scientific reports | Abbreviated Journal | Sci Rep-Uk |
Volume | 7 | Issue | Pages | 14458 | |
Keywords | A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) | ||||
Abstract | <script type='text/javascript'>document.write(unpmarked('Two-dimensional materials are known to harbour properties very different from those of their bulk counterparts. Recent years have seen the rise of atomically thin superconductors, with a caveat that superconductivity is strongly depleted unless enhanced by specific substrates, intercalants or adatoms. Surprisingly, the role in superconductivity of electronic states originating from simple free surfaces of two-dimensional materials has remained elusive to date. Here, based on first-principles calculations, anisotropic Eliashberg theory, and angle-resolved photoemission spectroscopy (ARPES), we show that surface states in few-monolayer MgB2 make a major contribution to the superconducting gap spectrum and density of states, clearly distinct from the widely known, bulk-like sigma-and pi-gaps. As a proof of principle, we predict and measure the gap opening on the magnesium-based surface band up to a critical temperature as high as similar to 30 K for merely six monolayers thick MgB2. These findings establish free surfaces as an unavoidable ingredient in understanding and further tailoring of superconductivity in atomically thin materials.')); | ||||
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Publisher | Nature Publishing Group | Place of Publication | London | Editor | |
Language | Wos | 000414231000059 | Publication Date | 2017-10-25 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2045-2322 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.259 | Times cited | 27 | Open Access | |
Notes | ; This work was supported by TOPBOF-UAntwerp, Research Foundation Flanders (FWO), the Foundation for Fundamental Research on Matter (FOM)-part of the Netherlands Organisation for Scientific Research, the Swedish Research Council (VR) and the Rontgen-Angstrom Cluster. P.v.A. acknowledges an Ubbo Emmius fellowship for his PhD studies. The computational resources and services used for the first-principles calculations in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Research Foundation Flanders (FWO) and the Flemish Government – department EWI. Eliashberg theory calculations were supported through the Swedish National Infrastructure for Computing (SNIC). We thank D. Lonza for technical assistance in the experimental part. ; | Approved | Most recent IF: 4.259 | ||
Call Number | UA @ lucian @ c:irua:147426 | Serial | 4875 | ||
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Author | Jiang, Y.; Mao, J.; Moldovan, D.; Masir, M.R.; Li, G.; Watanabe, K.; Taniguchi, T.; Peeters, F.M.; Andrei, E.Y. | ||||
Title | Tuning a circular p-n junction in graphene from quantum confinement to optical guiding | Type | A1 Journal article | ||
Year | 2017 | Publication | Nature nanotechnology | Abbreviated Journal | Nat Nanotechnol |
Volume | 12 | Issue | 11 | Pages | 1045-+ |
Keywords | A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) | ||||
Abstract | <script type='text/javascript'>document.write(unpmarked('The photon-like propagation of the Dirac electrons in graphene, together with its record-high electronic mobility(1-3), can lead to applications based on ultrafast electronic response and low dissipation(4-6). However, the chiral nature of the charge carriers that is responsible for the high mobility also makes it difficult to control their motion and prevents electronic switching. Here, we show how to manipulate the charge carriers by using a circular p-n junction whose size can be continuously tuned from the nanometre to the micrometre scale(7,8). The junction size is controlled with a dual-gate device consisting of a planar back gate and a point-like top gate made by decorating a scanning tunnelling microscope tip with a gold nanowire. The nanometre-scale junction is defined by a deep potential well created by the tip-induced charge. It traps the Dirac electrons in quantum-confined states, which are the graphene equivalent of the atomic collapse states (ACSs) predicted to occur at supercritically charged nuclei(9-13). As the junction size increases, the transition to the optical regime is signalled by the emergence of whispering-gallery modes(14-16), similar to those observed at the perimeter of acoustic or optical resonators, and by the appearance of a Fabry-Perot interference pattern(17-20) for junctions close to a boundary.')); | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000414531800011 | Publication Date | 2017-09-15 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1748-3387; 1748-3395 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 38.986 | Times cited | 65 | Open Access | |
Notes | ; The authors acknowledge funding provided by DOE-FG02-99ER45742 (STM/STS) and NSF DMR 1708158 (fabrication). Theoretical work was supported by ESF-EUROCORES-EuroGRAPHENE, FWO VI and the Methusalem program of the Flemish government. ; | Approved | Most recent IF: 38.986 | ||
Call Number | UA @ lucian @ c:irua:147406 | Serial | 4902 | ||
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Author | Moldovan, D.; Masir, M.R.; Peeters, F.M. | ||||
Title | Magnetic field dependence of the atomic collapse state in graphene | Type | A1 Journal article | ||
Year | 2018 | Publication | 2D materials | Abbreviated Journal | 2D Mater |
Volume | 5 | Issue | 1 | Pages | 015017 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | <script type='text/javascript'>document.write(unpmarked('Quantum electrodynamics predicts that heavy atoms (Z \u003E Z(c) approximate to 170) will undergo the process of atomic collapse where electrons sink into the positron continuum and a new family of so-called collapsing states emerges. The relativistic electrons in graphene exhibit the same physics but at a much lower critical charge (Z(c) approximate to 1) which has made it possible to confirm this phenomenon experimentally. However, there exist conflicting predictions on the effect of a magnetic field on atomic collapse. These theoretical predictions are based on the continuum Dirac-Weyl equation, which does not have an exact analytical solution for the interplay of a supercritical Coulomb potential and the magnetic field. Approximative solutions have been proposed, but because the two effects compete on similar energy scales, the theoretical treatment varies depending on the regime which is being considered. These limitations are overcome here by starting from a tight-binding approach and computing exact numerical results. By avoiding special limit cases, we found a smooth evolution between the different regimes. We predict that the atomic collapse effect persists even after the magnetic field is activated and that the critical charge remains unchanged. We show that the atomic collapse regime is characterized: (1) by a series of Landau level anticrossings and (2) by the absence of root B scaling of the Landau levels with regard to magnetic field strength.')); | ||||
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Publisher | IOP Publishing | Place of Publication | Bristol | Editor | |
Language | Wos | 000415015000001 | Publication Date | 2017-10-26 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2053-1583 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.937 | Times cited | 13 | Open Access | |
Notes | ; We thank Eva Andrei, Jinhai Mao and Yuhang Jiang for insightful discussions. This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem Funding of the Flemish Government. ; | Approved | Most recent IF: 6.937 | ||
Call Number | UA @ lucian @ c:irua:147361UA @ admin @ c:irua:147361 | Serial | 4884 | ||
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Author | Kus, M.; Altantzis, T.; Vercauteren, S.; Caretti, I.; Leenaerts, O.; Batenburg, K.J.; Mertens, M.; Meynen, V.; Partoens, B.; Van Doorslaer, S.; Bals, S.; Cool, P. | ||||
Title | Mechanistic Insight into the Photocatalytic Working of Fluorinated Anatase {001} Nanosheets | Type | A1 Journal article | ||
Year | 2017 | Publication | The journal of physical chemistry: C : nanomaterials and interfaces | Abbreviated Journal | J Phys Chem C |
Volume | 121 | Issue | 121 | Pages | 26275-26286 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); Laboratory of adsorption and catalysis (LADCA) | ||||
Abstract | Anatase nanosheets with exposed {001} facets have gained increasing interest for photocatalytic applications. To fully understand the structure-to-activity relation, combined experimental and computational methods have been exploited. Anatase nanosheets were prepared under hydrothermal conditions in the presence of fluorine ions. High resolution scanning transmission electron microscopy was used to fully characterize the synthesized material, confirming the TiO2 nanosheet morphology. Moreover, the surface structure and composition of a single nanosheet could be determined by annular bright-field scanning transmission electron microscopy (ABF-STEM) and STEM electron energy loss spectroscopy (STEM-EELS). The photocatalytic activity was tested for the decomposition of organic dyes rhodamine 6G and methyl orange and compared to a reference TiO2 anatase sample. The anatase nanosheets with exposed {001} facets revealed a significantly lower photocatalytic activity compared to the reference. In order to understand the mechanism for the catalytic performance, and to investigate the role of the presence of F−, light-induced electron paramagnetic resonance (EPR) experiments were performed. The EPR results are in agreement with TEM, proving the presence of Ti3+ species close to the surface of the sample and allowing the analysis of the photoinduced formation of paramagnetic species. Further, ab initio calculations of the anisotropic effective mass of electrons and electron holes in anatase show a very high effective mass of electrons in the [001] direction, having a negative impact on the mobility of electrons toward the {001} surface and thus the photocatalysis. Finally, motivated by the experimental results that indicate the presence of fluorine atoms at the surface, we performed ab initio calculations to determine the position of the band edges in anatase slabs with different terminations of the {001} surface. The presence of fluorine atoms near the surface is shown to strongly shift down the band edges, which indicates another reason why it can be expected that the prepared samples with a large amount of {001} surface, but with fluorine atoms near the surface, show only a low photocatalytic activity. |
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000417228500017 | Publication Date | 2017-11-30 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1932-7447 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.536 | Times cited | 20 | Open Access | OpenAccess |
Notes | The authors acknowledge the University of Antwerp for financial support in the frame of a GOA project. S.B. acknowledges funding from the European Research Council under the Seventh Framework Program (FP7), ERC Grant No. 335078 COLOURATOM. S.V.D. and V.M. acknowledge funding from the Fund for Scientific Research-Flanders (G.0687.13). T.A. acknowledges financial support from the Research Foundation Flanders (FWO, Belgium) through a postdoctoral grant. (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); saraecas; ECAS_Sara; | Approved | Most recent IF: 4.536 | ||
Call Number | EMAT @ emat @c:irua:147240UA @ admin @ c:irua:147240 | Serial | 4771 | ||
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Author | De Beule, C. | ||||
Title | Confined quantum systems in topological insulator heterostructures | Type | Doctoral thesis | ||
Year | 2017 | Publication | Abbreviated Journal | ||
Volume | Issue | Pages | 141 p. | ||
Keywords | Doctoral thesis; Condensed Matter Theory (CMT) | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | Publication Date | |||
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ISSN | ISBN | Additional Links | UA library record | ||
Impact Factor | Times cited | Open Access | |||
Notes | Approved | no | |||
Call Number | UA @ admin @ c:irua:147217 | Serial | 7725 | ||
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Author | Momot, A.; Amini, M.N.; Reekmans, G.; Lamoen, D.; Partoens, B.; Slocombe, D.R.; Elen, K.; Adriaensens, P.; Hardy, A.; Van Bael, M.K. | ||||
Title | A novel explanation for the increased conductivity in annealed Al-doped ZnO: an insight into migration of aluminum and displacement of zinc | Type | A1 Journal article | ||
Year | 2017 | Publication | Physical chemistry, chemical physics | Abbreviated Journal | Phys Chem Chem Phys |
Volume | 19 | Issue | 40 | Pages | 27866-27877 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | A combined experimental and first-principles study is performed to study the origin of conductivity in ZnO:Al nanoparticles synthesized under controlled conditions via a reflux route using benzylamine as a solvent. The experimental characterization of the samples by Raman, nuclear magnetic resonance (NMR) and conductivity measurements indicates that upon annealing in nitrogen, the Al atoms at interstitial positions migrate to the substitutional positions, creating at the same time Zn interstitials. We provide evidence for the fact that the formed complex of AlZn and Zni corresponds to the origin of the Knight shifted peak (KS) we observe in 27Al NMR. As far as we know, the role of this complex has not been discussed in the literature to date. However, our first-principles calculations show that such a complex is indeed energetically favoured over the isolated Al interstitial positions. In our calculations we also address the charge state of the Al interstitials. Further, Zn interstitials can migrate from Al_Zn and possibly also form Zn clusters, leading to the observed increased conductivity. |
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000413290500073 | Publication Date | 2017-10-09 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1463-9076 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.123 | Times cited | 26 | Open Access | OpenAccess |
Notes | We want to thank the Interuniversity Attraction Poles Programme (P7/05) initiated by the Belgian Science Policy Office (BELSPO) for the financial support. We also acknowledge the Research Foundation Flanders (FWO-Vlaanderen) for support via the MULTIMAR WOG project and under project No. G018914. The computational parts were carried out using the HPC infrastructure at the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center VSC, supported financially by the Hercules foundation and the Flemish Government (EWI Department). | Approved | Most recent IF: 4.123 | ||
Call Number | EMAT @ emat @c:irua:146878 | Serial | 4760 | ||
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Author | Nascimento, J.S.; da Costa, D.R.; Zarenia, M.; Chaves, A.; Pereira, J.M., Jr. | ||||
Title | Magnetic properties of bilayer graphene quantum dots in the presence of uniaxial strain | Type | A1 Journal article | ||
Year | 2017 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
Volume | 96 | Issue | 11 | Pages | 115428 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Using the tight-binding approach coupled with mean-field Hubbard model, we theoretically study the effect of mechanical deformations on the magnetic properties of bilayer graphene (BLG) quantum dots (QDs). Results are obtained for AA-and AB(Bernal)-stacked BLG QDs, considering different geometries (hexagonal, triangular and square shapes) and edge types (armchair and zigzag edges). In the absence of strain, our results show that (i) the magnetization is affected by taking different dot sizes only for hexagonal BLG QDs with zigzag edges, exhibiting different critical Hubbard interactions, and (ii) the magnetization does not depend on the interlayer hopping energies, except for the geometries with zigzag edges and AA stacking. In the presence of in-plane and uniaxial strain, for all geometries we obtain two different magnetization regimes depending on the applied strain amplitude. The appearance of such different regimes is due to the breaking of layer and sublattice symmetries in BLG QDs. | ||||
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Publisher | American Physical Society | Place of Publication | New York, N.Y | Editor | |
Language | Wos | 000411077400008 | Publication Date | 2017-09-18 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2469-9969; 2469-9950 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 4 | Open Access | |
Notes | ; This work was financially supported by CNPq, FUNCAP, CAPES Foundation, the Flemish Science Foundation (FWO-Vl), and the Brazilian Program Science Without Borders (CsF). ; | Approved | Most recent IF: 3.836 | ||
Call Number | UA @ lucian @ c:irua:146751 | Serial | 4788 | ||
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Author | Zhang, L.-F.; Flammia, L.; Covaci, L.; Perali, A.; Milošević, M.V. | ||||
Title | Multifaceted impact of a surface step on superconductivity in atomically thin films | Type | A1 Journal article | ||
Year | 2017 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
Volume | 96 | Issue | 10 | Pages | 104509 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Recent experiments show that an atomic step on the surface of atomically thin metallic films can strongly affect electronic transport. Here we reveal multiple and versatile effects that such a surface step can have on superconductivity in ultrathin films. By solving the Bogoliubov-de Gennes equations self-consistently in this regime, where quantum confinement dominates the emergent physics, we show that the electronic structure is profoundly modified on the two sides of the step, as is the spatial distribution of the superconducting order parameter and its dependence on temperature and electronic gating. Furthermore, the surface step changes nontrivially the transport properties both in the proximity-induced superconducting pair correlations and the Josephson effect, depending on the step height. These results offer a new route to tailor superconducting circuits and design atomically thin heterojunctions made of one same material. | ||||
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Corporate Author | Thesis | ||||
Publisher | American Physical Society | Place of Publication | New York, N.Y | Editor | |
Language | Wos | 000411076000012 | Publication Date | 2017-09-18 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2469-9969; 2469-9950 | 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 Research Foundation Flanders (FWO-Vlaanderen), the Special Research Funds of the University of Antwerp (TOPBOF project) and the Italian MIUR through the PRIN 2015 program (Contract No. 2015C5SEJJ001). ; | Approved | Most recent IF: 3.836 | ||
Call Number | UA @ lucian @ c:irua:146750 | Serial | 4790 | ||
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Author | Mirzakhani, M.; Zarenia, M.; Vasilopoulos, P.; Ketabi, S.A.; Peeters, F.M. | ||||
Title | Landau levels in biased graphene structures with monolayer-bilayer interfaces | Type | A1 Journal article | ||
Year | 2017 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
Volume | 96 | Issue | 12 | Pages | 125430 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | The electron energy spectrum in monolayer-bilayer-monolayer and in bilayer-monolayer-bilayer graphene structures is investigated and the effects of a perpendicular magnetic field and electric bias are studied. Different types of monolayer-bilayer interfaces are considered as zigzag (ZZ) or armchair (AC) junctions which modify considerably the bulk Landau levels (LLs) when the spectra are plotted as a function of the center coordinate of the cyclotron orbit. Far away from the two interfaces, one obtains the well-known LLs for extended monolayer or bilayer graphene. The LL structure changes significantly at the two interfaces or junctions where the valley degeneracy is lifted for both types of junctions, especially when the distance between them is approximately equal to the magnetic length. Varying the nonuniform bias and the width of this junction-to-junction region in either structure strongly influence the resulting spectra. Significant differences exist between ZZ and AC junctions in both structures. The densities of states (DOSs) for unbiased structures are symmetric in energy whereas those for biased structures are asymmetric. An external bias creates interface LLs in the gaps between the LLs of the unbiased system in which the DOS can be quite small. Such a pattern of LLs can be probed by scanning tunneling microscopy. | ||||
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Publisher | American Physical Society | Place of Publication | New York, N.Y | Editor | |
Language | Wos | 000411321800003 | Publication Date | 2017-09-21 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2469-9969; 2469-9950 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 6 | Open Access | |
Notes | ; This work was supported by the BOF-UA (Bijzonder Onderzoeks Fonds), the Canadian NSERC through Grant No. OGP0121756 (P.V.), and the Methusalem Program of the Flemish Government. ; | Approved | Most recent IF: 3.836 | ||
Call Number | UA @ lucian @ c:irua:146746 | Serial | 4787 | ||
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Author | Berdiyorov, G.R.; Milošević, M.V.; Hernandez-Nieves, A.D.; Peeters, F.M.; Dominguez, D. | ||||
Title | Microfluidic manipulation of magnetic flux domains in type-I superconductors : droplet formation, fusion and fission | Type | A1 Journal article | ||
Year | 2017 | Publication | Scientific reports | Abbreviated Journal | Sci Rep-Uk |
Volume | 7 | Issue | Pages | 12129 | |
Keywords | A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) | ||||
Abstract | The magnetic flux domains in the intermediate state of type-I superconductors are known to resemble fluid droplets, and their dynamics in applied electric current is often cartooned as a “dripping faucet”. Here we show, using the time-depended Ginzburg-Landau simulations, that microfluidic principles hold also for the determination of the size of the magnetic flux-droplet as a function of the applied current, as well as for the merger or splitting of those droplets in the presence of the nanoengineered obstacles for droplet motion. Differently from fluids, the flux-droplets in superconductors are quantized and dissipative objects, and their pinning/depinning, nucleation, and splitting occur in a discretized form, all traceable in the voltage measured across the sample. At larger applied currents, we demonstrate how obstacles can cause branching of laminar flux streams or their transformation into mobile droplets, as readily observed in experiments. | ||||
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Publisher | Nature Publishing Group | Place of Publication | London | Editor | |
Language | Wos | 000411416700032 | Publication Date | 2017-09-15 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2045-2322 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.259 | Times cited | 1 | Open Access | |
Notes | ; This work was supported by the Research Foundation Flanders (FWO) and the MINCYT-FWO FW/14/04 bilateral project. A.D.H. and D.D. acknowledge support from CONICET (Grant No. PIP111220150100218), CNEA and ANPCyT (Grant No. PICT2014-1382). ; | Approved | Most recent IF: 4.259 | ||
Call Number | UA @ lucian @ c:irua:146743 | Serial | 4789 | ||
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Author | Zografos, O.; Manfrini, M.; Vaysset, A.; Sorée, B.; Ciubotaru, F.; Adelmann, C.; Lauwereins, R.; Raghavan, P.; Radu, I.P. | ||||
Title | Exchange-driven magnetic logic | Type | A1 Journal article | ||
Year | 2017 | Publication | Scientific reports | Abbreviated Journal | Sci Rep-Uk |
Volume | 7 | Issue | Pages | 12154 | |
Keywords | A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) | ||||
Abstract | Direct exchange interaction allows spins to be magnetically ordered. Additionally, it can be an efficient manipulation pathway for low-powered spintronic logic devices. We present a novel logic scheme driven by exchange between two distinct regions in a composite magnetic layer containing a bistable canted magnetization configuration. By applying a magnetic field pulse to the input region, the magnetization state is propagated to the output via spin-to-spin interaction in which the output state is given by the magnetization orientation of the output region. The dependence of this scheme with input field conditions is extensively studied through a wide range of micromagnetic simulations. These results allow different logic operating modes to be extracted from the simulation results, and majority logic is successfully demonstrated. | ||||
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Corporate Author | Thesis | ||||
Publisher | Nature Publishing Group | Place of Publication | London | Editor | |
Language | Wos | 000411434900020 | Publication Date | 2017-09-18 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2045-2322 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.259 | Times cited | 7 | Open Access | |
Notes | ; ; | Approved | Most recent IF: 4.259 | ||
Call Number | UA @ lucian @ c:irua:146742 | Serial | 4784 | ||
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