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Author Embon, L.; Anahory, Y.; Jelić, Z.L.; Lachman, E.O.; Myasoedov, Y.; Huber, M.E.; Mikitik, G.P.; Silhanek, A.V.; Milošević, M.V.; Gurevich, A.; Zeldov, E.
Title Imaging of super-fast dynamics and flow instabilities of superconducting vortices Type (up) A1 Journal article
Year 2017 Publication Nature communications Abbreviated Journal Nat Commun
Volume 8 Issue Pages 85
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract Quantized magnetic vortices driven by electric current determine key electromagnetic properties of superconductors. While the dynamic behavior of slow vortices has been thoroughly investigated, the physics of ultrafast vortices under strong currents remains largely unexplored. Here, we use a nanoscale scanning superconducting quantum interference device to image vortices penetrating into a superconducting Pb film at rates of tens of GHz and moving with velocities of up to tens of km/s, which are not only much larger than the speed of sound but also exceed the pair-breaking speed limit of superconducting condensate. These experiments reveal formation of mesoscopic vortex channels which undergo cascades of bifurcations as the current and magnetic field increase. Our numerical simulations predict metamorphosis of fast Abrikosov vortices into mixed Abrikosov-Josephson vortices at even higher velocities. This work offers an insight into the fundamental physics of dynamic vortex states of superconductors at high current densities, crucial for many applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000405900400002 Publication Date 2017-07-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2041-1723 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.124 Times cited 124 Open Access
Notes ; We would like to thank M.L. Rappaport for fruitful discussions and technical support. This work was supported by the US-Israel Binational Science Foundation (BSF) grant No. 2014155 and the Israel Science Foundation grant No. 132/14. A.G. was also supported by the United States Department of Energy under Grant No. DE-SC0010081. M.V.M. acknowledges support from Research Foundation-Flanders (FWO). The work of Z.L.J. and A.V.S. was partially supported by “Mandat d'Impulsion Scientifique” MIS F.4527.13 of the F.R.S.-FNRS. This work benefited from the support of COST action MP-1201. ; Approved Most recent IF: 12.124
Call Number UA @ lucian @ c:irua:144832 Serial 4720
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Author Bekaert, J.; Aperis, A.; Partoens, B.; Oppeneer, P.M.; Milošević, M.V.
Title Evolution of multigap superconductivity in the atomically thin limit : strain-enhanced three-gap superconductivity in monolayer MgB2 Type (up) A1 Journal article
Year 2017 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 96 Issue 9 Pages 094510
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Starting from first principles, we show the formation and evolution of superconducting gaps in MgB2 at its ultrathin limit. Atomically thin MgB2 is distinctly different from bulk MgB2 in that surface states become comparable in electronic density to the bulklike sigma and pi bands. Combining the ab initio electron-phonon coupling with the anisotropic Eliashberg equations, we showthat monolayer MgB2 develops three distinct superconducting gaps, on completely separate parts of the Fermi surface due to the emergent surface contribution. These gaps hybridize nontrivially with every extra monolayer added to the film owing to the opening of additional coupling channels. Furthermore, we reveal that the three-gap superconductivity in monolayer MgB2 is robust over the entire temperature range that stretches up to a considerably high critical temperature of 20 K. The latter can be boosted to >50K under biaxial tensile strain of similar to 4%, which is an enhancement that is stronger than in any other graphene-related superconductor known to date.
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Corporate Author Thesis
Publisher American Physical Society Place of Publication New York, N.Y Editor
Language Wos 000410166800008 Publication Date 2017-09-11
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 56 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 first-principles calculations have been carried out on the HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Centre (VSC), supported financially by the Hercules Foundation and the Flemish Government (EWI Department). 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:145623 Serial 4741
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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 (up) 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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Corporate Author Thesis
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 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 (up) 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 de Aquino, B.R.H.; Neek-Amal, M.; Milošević, M.V.
Title Unconventional two-dimensional vibrations of a decorated carbon nanotube under electric field : linking actuation to advanced sensing ability Type (up) A1 Journal article
Year 2017 Publication Scientific reports Abbreviated Journal Sci Rep-Uk
Volume 7 Issue Pages 13481
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract We show that a carbon nanotube decorated with different types of charged metallic nanoparticles exhibits unusual two-dimensional vibrations when actuated by applied electric field. Such vibrations and diverse possible trajectories are not only fundamentally important but also have minimum two characteristic frequencies that can be directly linked back to the properties of the constituents in the considered nanoresonator. Namely, those frequencies and the maximal deflection during vibrations are very distinctively dependent on the geometry of the nanotube, the shape, element, mass and charge of the nanoparticle, and are vastly tunable by the applied electric field, revealing the unique sensing ability of devices made of molecular filaments and metallic nanoparticles.
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Corporate Author Thesis
Publisher Nature Publishing Group Place of Publication London Editor
Language Wos 000413188600005 Publication Date 2017-10-12
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 Shahid Rajaee Teacher Training University. ; Approved Most recent IF: 4.259
Call Number UA @ lucian @ c:irua:146672 Serial 4796
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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 (up) 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 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 (up) 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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Corporate Author Thesis
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 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 (up) 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 Zhang, L.-F.; Covaci, L.; Milošević, M.V.
Title Topological phase transitions in small mesoscopic chiral p-wave superconductors Type (up) 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 Mulkers, J.; Van Waeyenberge, B.; Milošević, M.V.
Title Tunable Snell's law for spin waves in heterochiral magnetic films Type (up) A1 Journal article
Year 2018 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 97 Issue 10 Pages 104422
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Thin ferromagnetic films with an interfacially induced DMI exhibit nontrivial asymmetric dispersion relations that lead to unique and useful magnonic properties. Here we derive an analytical expression for the magnon propagation angle within the micromagnetic framework and show how the dispersion relation can be approximated with a comprehensible geometrical interpretation in the k space of the propagation of spin waves. We further explore the refraction of spin waves at DMI interfaces in heterochiral magnetic films, after deriving a generalized Snell's law tunable by an in-plane magnetic field, that yields analytical expressions for critical incident angles. The found asymmetric Brewster angles at interfaces of regions with different DMI strengths, adjustable by magnetic field, support the conclusion that heterochiral ferromagnetic structures are an ideal platform for versatile spin-wave guides.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000428238600006 Publication Date 2018-03-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 20 Open Access
Notes This work was supported by the Research Foundation- Flanders (FWO-Vlaanderen) through Project No. G098917N. Approved Most recent IF: 3.836
Call Number CMT @ cmt @c:irua:150118UA @ admin @ c:irua:150118 Serial 4915
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Author Klimin, S.N.; Tempere, J.; Milošević, M.V.
Title Diversified vortex phase diagram for a rotating trapped two-band Fermi gas in the BCS-BEC crossover Type (up) A1 Journal article
Year 2018 Publication New journal of physics Abbreviated Journal New J Phys
Volume 20 Issue 20 Pages 025010
Keywords A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT)
Abstract We report the equilibrium vortex phase diagram of a rotating two-band Fermi gas confined to a cylindrically symmetric parabolic trapping potential, using the recently developed finite-temperature effective field theory (Klimin et al 2016 Phys. Rev. A 94 023620). A non-monotonic resonant dependence of the free energy as a function of the temperature and the rotation frequency is revealed for a two-band superfluid. We particularly focus on novel features that appear as a result of interband interactions and can be experimentally resolved. The resonant dependence of the free energy is directly manifested in vortex phase diagrams, where areas of stability for both integer and fractional vortex states are found. The study embraces the BCS-BEC crossover regime and the entire temperature range below the critical temperature T-c. Significantly different behavior of vortex matter as a function of the interband coupling is revealed in the BCS and BEC regimes.
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Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos 000426002900001 Publication Date 2018-02-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1367-2630 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.786 Times cited 6 Open Access
Notes ; We thank C A R Sa de Melo and N Verhelst for valuable discussions. This work has been supported by the Research Foundation-Flanders (FWO-Vl), project nrs. G.0115.12N, G.0119.12N, G.0122.12N, G.0429.15N, G.0666.16N, by the Scientific Research Network of the Flemish Research Foundation, WO.033.09N, and by the Research Fund of the University of Antwerp. ; Approved Most recent IF: 3.786
Call Number UA @ lucian @ c:irua:149909UA @ admin @ c:irua:149909 Serial 4930
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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 (up) 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 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 (up) 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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Corporate Author Thesis
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 Berdiyorov, G.R.; Milošević, M.V.; Kusmartsev, F.; Peeters, F.M.; Savel'ev, S.
Title Josephson vortex loops in nanostructured Josephson junctions Type (up) 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 Pinto, N.; Rezvani, S.J.; Perali, A.; Flammia, L.; Milošević, M.V.; Fretto, M.; Cassiago, C.; De Leo, N.
Title Dimensional crossover and incipient quantum size effects in superconducting niobium nanofilms Type (up) A1 Journal article
Year 2018 Publication Scientific reports Abbreviated Journal Sci Rep-Uk
Volume 8 Issue 8 Pages 4710
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract Superconducting and normal state properties of Niobium nanofilms have been systematically investigated as a function of film thickness, on different substrates. The width of the superconductingto- normal transition for all films is remarkably narrow, confirming their high quality. The superconducting critical current density exhibits a pronounced maximum for thickness around 25 nm, marking the 3D-to-2D crossover. The magnetic penetration depth shows a sizeable enhancement for the thinnest films. Additional amplification effects of the superconducting properties have been obtained with sapphire substrates or squeezing the lateral size of the nanofilms. For thickness close to 20 nm we measured a doubled perpendicular critical magnetic field compared to its large thickness value, indicating shortening of the correlation length and the formation of small Cooper pairs. Our data analysis indicates an exciting interplay between quantum-size and proximity effects together with strong-coupling effects and the importance of disorder in the thinnest films, placing these nanofilms close to the BCS-BEC crossover regime.
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Corporate Author Thesis
Publisher Nature Publishing Group Place of Publication London Editor
Language Wos 000427588300011 Publication Date 2018-03-12
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 37 Open Access
Notes ; We thank Antonio Bianconi, Mauro Doria and Vincenzo Lacquaniti for useful discussions. We acknowledge the collaboration with Federica Celegato for AFM analysis and Sara Quercetti for the electrical properties characterization. A. P. and N. P. acknowledge financial support from University of Camerino FAR project CESEMN. We also acknowledge the collaboration within the MultiSuper International Network (http://www.multisuper.org) for exchange of ideas and suggestions. ; Approved Most recent IF: 4.259
Call Number UA @ lucian @ c:irua:150843UA @ admin @ c:irua:150843 Serial 4965
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Author Flammia, L.; Zhang, L.-F.; Covaci, L.; Perali, A.; Milošević, M.V.
Title Superconducting nanoribbon with a constriction : a quantum-confined Josephson junction Type (up) A1 Journal article
Year 2018 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 97 Issue 13 Pages 134514
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Extended defects are known to strongly affect nanoscale superconductors. Here, we report the properties of superconducting nanoribbons with a constriction formed between two adjacent step edges by solving the Bogoliubov-de Gennes equations self-consistently in the regime where quantum confinement is important. Since the quantum resonances of the superconducting gap in the constricted area are different from the rest of the nanoribbon, such constriction forms a quantum-confined S-S'-S Josephson junction, with a broadly tunable performance depending on the length and width of the constriction with respect to the nanoribbon, and possible gating. These findings provide an intriguing approach to further tailor superconducting quantum devices where Josephson effect is of use.
Address
Corporate Author Thesis
Publisher American Physical Society Place of Publication New York, N.Y Editor
Language Wos 000430161500004 Publication Date 2018-04-17
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), the Italian MIUR through the PRIN 2015 program (Contract No. 2015C5SEJJ001), the MultiSuper network, and the EU-COST NANOCOHYBRI action CA16218. ; Approved Most recent IF: 3.836
Call Number UA @ lucian @ c:irua:150754UA @ admin @ c:irua:150754 Serial 4980
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Author Mulkers, J.; Hals, K.M.D.; Leliaert, J.; Milošević, M.V.; Van Waeyenberge, B.; Everschor-Sitte, K.
Title Effect of boundary-induced chirality on magnetic textures in thin films Type (up) A1 Journal article
Year 2018 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 98 Issue 6 Pages 064429
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract In the quest for miniaturizing magnetic devices, the effects of boundaries and surfaces become increasingly important. Here we show how the recently predicted boundary-induced Dzyaloshinskii-Moriya interaction (DMI) affects the magnetization of ferromagnetic films with a C-infinity v symmetry and a perpendicular magnetic anisotropy. For an otherwise uniformly magnetized film, we find a surface twist when the magnetization in the bulk is canted by an in-plane external field. This twist at the surfaces caused by the boundary-induced DMI differs from the common canting caused by internal DMI observed at the edges of a chiral magnet. Furthermore, we find that the surface twist due to the boundary-induced DMI strongly affects the width of the domain wall at the surfaces. We also find that the skyrmion radius increases in the depth of the film, with the average size of the skyrmion increasing with boundary-induced DMI. This increase suggests that the boundary-induced DMI contributes to the stability of the skyrmion.
Address
Corporate Author Thesis
Publisher American Physical Society Place of Publication New York, N.Y Editor
Language Wos 000443394600004 Publication Date 2018-08-31
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 9 Open Access
Notes ; The authors thank Matthias Sitte and Andre Thiaville for fruitful discussions. This work was supported by the Fonds Wetenschappelijk Onderzoek (FWO-Vlaanderen) through Project No. G098917N and the German Research Foundation (DFG) under the Project No. EV 196/2-1. J.L. is supported by the Ghent University Special Research Fund with a BOF postdoctoral fellowship. ; Approved Most recent IF: 3.836
Call Number UA @ lucian @ c:irua:153706UA @ admin @ c:irua:153706 Serial 5093
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Author Leliaert, J.; Gypens, P.; Milošević, M.V.; Van Waeyenberge, B.; Mulkers, J.
Title Coupling of the skyrmion velocity to its breathing mode in periodically notched nanotracks Type (up) A1 Journal article
Year 2019 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys
Volume 52 Issue 2 Pages 024003
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract A thorough understanding of the skyrmion motion through nanotracks is a prerequisite to realize the full potential of spintronic applications like the skyrmion racetrack memory. One of the challenges is to place the data, i.e. skyrmions, on discrete fixed positions, e.g. below a read or write head. In the domain-wall racetrack memory, one proposed solution to this problem was patterning the nanotrack with notches. Following this approach, this paper reports on the skyrmion mobility through a nanotrack with periodic notches (constrictions) made using variations in the chiral Dzyaloshinskii-Moriya interaction. We observe that such notches induce a coupling between the mobility and the skyrmion breathing mode, which manifests itself as velocity-dependent oscillations of the skyrmion diameter and plateaus in which the velocity is independent of the driving force. Despite the fact that domain walls are far more rigid objects than skyrmions, we were able to perform an analogous study and, surprisingly, found even larger plateaus of constant velocity. For both systems it is straightforward to tune the velocity at these plateaus by changing the design of the notched nanotrack geometry, e.g. by varying the distance between the notches. Therefore, the notch-induced coupling between the excited modes and the mobility could offer a strategy to stabilize the velocity against unwanted perturbations in racetrack-like applications. In the last part of the paper we focus on the low-current mobility regimes, whose very rich dynamics at nonzero temperatures are very similar to the operating principle of recently developed probabilistic logic devices. This proves that the mobility of nanomagnetic structures through a periodically modulated track is not only interesting from a fundamental point of view, but has a future in many spintronic applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000449169100001 Publication Date 2018-10-11
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 10 Open Access
Notes ; This work is supported by Fonds Wetenschappelijk Onderzoek (FWO-Vlaanderen) through Project No. G098917N. JL acknowledges his postdoctoral fellowships by the Ghent University special research fund (BOF) and FWO-Vlaanderen. The authors gratefully acknowledge the support of NVIDIA Corporation through donation of Titan Xp and Titan V GPU cards used for this research. ; Approved Most recent IF: 2.588
Call Number UA @ admin @ c:irua:155359 Serial 5202
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Author Menezes, R.M.; Mulkers, J.; de Souza Silva, C.C.; Milošević, M.V.
Title Deflection of ferromagnetic and antiferromagnetic skyrmions at heterochiral interfaces Type (up) A1 Journal article
Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 99 Issue 10 Pages 104409
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Devising magnetic nanostructures with spatially heterogeneous Dzyaloshinskii-Moriya interaction (DMI) is a promising pathway toward advanced confinement and control of magnetic skyrmions in potential devices. Here we discuss theoretically how a skyrmion interacts with a heterochiral interface using micromagnetic simulations and analytic arguments. We show that a heterochiral interface deflects the trajectory of ferromagnetic (FM) skyrmions, and that the extent of such deflection is tuned by the applied spin-polarized current and the difference in DMI across the interface. Further, we show that this deflection is characteristic of the FM skyrmion, and it is completely absent in the antiferromagnetic (AFM) case. In turn, we reveal that the AFM skyrmion achieves much higher velocities than its FM counterpart, yet experiences far stronger confinement in nanoengineered heterochiral tracks, which reinforces AFM skyrmions as a favorable choice for skyrmion-based devices.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000460720600005 Publication Date 2019-03-07
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 19 Open Access
Notes ; This work was supported by the Research Foundation-Flanders (FWO-Vlaanderen) and Brazilian Agencies FACEPE under Grant No. APQ-0198-1.05/14, CAPES and CNPq. ; Approved Most recent IF: 3.836
Call Number UA @ admin @ c:irua:158557 Serial 5203
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Author Lozano, D.P.; Couet, S.; Petermann, C.; Hamoir, G.; Jochum, J.K.; Picot, T.; Menendez, E.; Houben, K.; Joly, V.; Antohe, V.A.; Hu, M.Y.; Leu, B.M.; Alatas, A.; Said, A.H.; Roelants, S.; Partoens, B.; Milošević, M.V.; Peeters, F.M.; Piraux, L.; Van de Vondel, J.; Vantomme, A.; Temst, K.; Van Bael, M.J.
Title Experimental observation of electron-phonon coupling enhancement in Sn nanowires caused by phonon confinement effects Type (up) A1 Journal article
Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 99 Issue 6 Pages 064512
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Reducing the size of a superconductor below its characteristic length scales can either enhance or suppress its critical temperature (T-c). Depending on the bulk value of the electron-phonon coupling strength, electronic and phonon confinement effects will play different roles in the modification of T-c. Experimentally disentangling each contribution has remained a challenge. We have measured both the phonon density of states and T-c of Sn nanowires with diameters of 18, 35, and 100 nm in order to quantify the effects of phonon confinement on superconductivity. We observe a shift of the phonon frequency towards the low-energy region and an increase in the electron-phonon coupling constant that can account for the measured increase in T-c.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000459322400005 Publication Date 2019-02-21
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 8 Open Access
Notes ; We would like to thanks Jeroen Scheerder and Wout Keijers for their help and assistance during the low-temperature measurements. This work was supported by the Research Foundation Flanders (FWO), the Concerted Research Action (GOA/14/ 007), the Federation Wallonie-Bruxelles (ARC 13/18-052, Supracryst) and the Fonds de la Recherche Scientifique -FNRS under Grant No. T.0006.16. The authors acknowledge Hercules Stichting (Project Nos. AKUL/13/19 and AKUL/13/25). D.P.L. thanks the FWO for financial support. This research used resources of the Advanced Photon Source, a US Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. ; Approved Most recent IF: 3.836
Call Number UA @ admin @ c:irua:158621 Serial 5212
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Author Gonzalez-Garcia, A.; Lopez-Perez, W.; Gonzalez-Hernandez, R.; Rodriguez, J.A.; Milošević, M.V.; Peeters, F.M.
Title Tunable 2D-gallium arsenide and graphene bandgaps in a graphene/GaAs heterostructure : an ab initio study Type (up) A1 Journal article
Year 2019 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat
Volume 31 Issue 26 Pages 265502
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The bandgap behavior of 2D-GaAs and graphene have been investigated with van der Waals heterostructured into a yet unexplored graphene/GaAs bilayer, under both uniaxial stress along c axis and different planar strain distributions. The 2D-GaAs bandgap nature changes from Gamma-K indirect in isolated monolayer to Gamma-Gamma direct in graphene/GaAs bilayer. In the latter, graphene exhibits a bandgap of 5 meV. The uniaxial stress strongly affects the graphene electronic bandgap, while symmetric in-plane strain does not open the bandgap in graphene. Nevertheless, it induces remarkable changes on the GaAs bandgap-width around the Fermi level. However, when applying asymmetric in-plane strain to graphene/GaAs, the graphene sublattice symmetry is broken, and the graphene bandgap is open at the Fermi level to a maximum width of 814 meV. This value is much higher than that reported for just graphene under asymmetric strain. The Gamma-Gamma direct bandgap of GaAs remains unchanged in graphene/ GaAs under different types of applied strain. The analyses of phonon dispersion and the elastic constants yield the dynamical and mechanical stability of the graphene/GaAs system, respectively. The calculated mechanical properties for bilayer heterostructure are better than those of their constituent monolayers. This finding, together with the tunable graphene bandgap not only by the strength but also by the direction of the strain, enhance the potential for strain engineering of ultrathin group-III-V electronic devices hybridized by graphene.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000465887100001 Publication Date 2019-03-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.649 Times cited 6 Open Access
Notes ; This work has been carried out with the financial support of Universidad del Norte and Colciencias (Administrative Department of Science, Technology and Research of Colombia) under Convocatoria 712-Convocatoria para proyectos de investigacion en Ciencias Basicas, ano 2015, Cod: 121571250192, Contrato 110-216; and the partial support of DGAPA-UNAM project IN114817-3. The authors gratefully acknowledge the support from the High Performance Computing core facility CalcUA and the TOPBOF project at the University of Antwerp, Belgium; DGTIC-UNAM under project LANCAD-UNAM-DGTIC-150, and the computing time granted on the supercomputer Mogon at Johannes Gutenberg University Mainz (hpc.uni-mainz.de). ; Approved Most recent IF: 2.649
Call Number UA @ admin @ c:irua:160216 Serial 5236
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Author Bekaert, J.; Petrov, M.; Aperis, A.; Oppeneer, P.M.; Milošević, M.V.
Title Hydrogen-induced high-temperature superconductivity in two-dimensional materials : the example of hydrogenated monolayer MgB2 Type (up) A1 Journal article
Year 2019 Publication Physical review letters Abbreviated Journal Phys Rev Lett
Volume 123 Issue 7 Pages 077001
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Hydrogen-based compounds under ultrahigh pressure, such as the polyhydrides H3S and LaH10, superconduct through the conventional electron-phonon coupling mechanism to attain the record critical temperatures known to date. Here we exploit the intrinsic advantages of hydrogen to strongly enhance phonon-mediated superconductivity in a completely different system, namely, a two-dimensional material with hydrogen adatoms. We find that van Hove singularities in the electronic structure, originating from atomiclike hydrogen states, lead to a strong increase of the electronic density of states at the Fermi level, and thus of the electron-phonon coupling. Additionally, the emergence of high-frequency hydrogen-related phonon modes in this system boosts the electron-phonon coupling further. As a concrete example, we demonstrate the effect of hydrogen adatoms on the superconducting properties of monolayer MgB2, by solving the fully anisotropic Eliashberg equations, in conjunction with a first-principles description of the electronic and vibrational states, and their coupling. We show that hydrogenation leads to a high critical temperature of 67 K, which can be boosted to over 100 K by biaxial tensile strain.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000480611900017 Publication Date 2019-08-14
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 42 Open Access
Notes ; This work was supported by TOPBOF-UAntwerp, Research Foundation-Flanders (FWO), the Swedish Research Council (VR), the Rontgen-Angstrom Cluster, and the EU-COST Action CA16218. J.B. acknowledges support of a postdoctoral fellowship of the FWO. 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 FWO and the Flemish Government-department EWI. Eliashberg theory calculations were supported through the Swedish National Infrastructure for Computing (SNIC). We would also like to acknowledge useful discussions with Bart Partoens, Jacques Tempere, and Matthieu Verstraete. ; Approved Most recent IF: 8.462
Call Number UA @ admin @ c:irua:161816 Serial 5415
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Author Houben, K.; Jochum, J.K.; Lozano, D.P.; Bisht, M.; Menendez, E.; Merkel, D.G.; Ruffer, R.; Chumakov, A., I; Roelants, S.; Partoens, B.; Milošević, M.V.; Peeters, F.M.; Couet, S.; Vantomme, A.; Temst, K.; Van Bael, M.J.
Title In situ study of the \alpha-Sn to \beta-Sn phase transition in low-dimensional systems : phonon behavior and thermodynamic properties Type (up) A1 Journal article
Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 100 Issue 7 Pages 075408
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The densities of phonon states of thin Sn films on InSb substrates are determined during different stages of the alpha-Sn to beta-Sn phase transition using nuclear inelastic x-ray scattering. The vibrational entropy and internal energy per atom as a function of temperature are obtained by numerical integration of the phonon density of states. The free energy as a function of temperature for the nanoscale samples is compared to the free energy obtained from ab initio calculations of bulk tin in the alpha-Sn and beta-Sn phase. In thin films this phase transition is governed by the interplay between the vibrational behavior of the film (the phase transition is driven by the vibrational entropy) and the stabilizing influence of the substrate (which depends on the film thickness). This brings a deeper understanding of the role of lattice vibrations in the phase transition of nanoscale Sn.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000478992800005 Publication Date 2019-08-08
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 8 Open Access
Notes ; This work was supported by the Research Foundation Flanders (FWO) and the Concerted Research Action (Grant No. GOA14/007). K.H., S.C., D.P.L., and E.M. wish to thank the FWO for financial support. The authors gratefully acknowledge the European Synchrotron Radiation Facility (ESRF) for the granted beam time and the use of the in situ UHV preparation chamber. The authors thank B. Opperdoes for technical support and T. Peissker and R. Lieten for fruitful discussions. ; Approved Most recent IF: 3.836
Call Number UA @ admin @ c:irua:161836 Serial 5416
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Author Cordoba, R.; Orus, P.; Jelić, Ž.L.; Sese, J.; Ricardo Ibarra, M.; Guillamon, I.; Vieira, S.; Jose Palacios, J.; Suderow, H.; Milošević, M.V.; Maria De Teresa, J.
Title Long-range vortex transfer in superconducting nanowires Type (up) A1 Journal article
Year 2019 Publication Scientific reports Abbreviated Journal Sci Rep-Uk
Volume 9 Issue 9 Pages 12386
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract Under high-enough values of perpendicularly-applied magnetic field and current, a type-II superconductor presents a finite resistance caused by the vortex motion driven by the Lorentz force. To recover the dissipation-free conduction state, strategies for minimizing vortex motion have been intensely studied in the last decades. However, the non-local vortex motion, arising in areas depleted of current, has been scarcely investigated despite its potential application for logic devices. Here, we propose a route to transfer vortices carried by non-local motion through long distances (up to 10 micrometers) in 50 nm-wide superconducting WC nanowires grown by Ga+ Focused Ion Beam Induced Deposition. A giant non-local electrical resistance of 36 Omega has been measured at 2 K in 3 mu m-long nanowires, which is 40 times higher than signals reported for wider wires of other superconductors. This giant effect is accounted for by the existence of a strong edge confinement potential that hampers transversal vortex displacements, allowing the long-range coherent displacement of a single vortex row along the superconducting channel. Experimental results are in good agreement with numerical simulations of vortex dynamics based on the time-dependent Ginzburg-Landau equations. Our results pave the way for future developments on information technologies built upon single vortex manipulation in nano-superconductors.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000482708800004 Publication Date 2019-08-27
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 13 Open Access
Notes ; This work was supported by the financial support from Spanish Ministry of Economy and Competitiveness through the projects MAT2015-69725-REDT, MAT2017-82970-C2-1-R and MAT2017-82970-C2-2-R, PIE201760E027, including FEDER funding, FIS2017-84330-R, MDM-2014-0377, FIS2016-80434-P and the Fundacion Ramon Areces, EU ERC (Grant Agreement No. 679080), COST Grant No. CA16128 and STSM Grant from COST Action CA16218, and from regional Gobierno de Aragon (grants E1317R and E2817R) with European Social Fund (Construyendo Europa desde Aragon) and Comunidad de Madrid through project Nanofrontmag-CM (Grant No. S2013/MIT-2850). R.C. acknowledges Juan de la Cierva-Incorporacion 2014 program. Authors strongly acknowledge Laura Casado and Isabel Rivas for TEM sample preparation, Rodrigo Fernandez-Pacheco for TEM experiments and Ruben Valero for the UV lithography process. The microscopy works have been conducted in the “Laboratorio de Microscopias Avanzadas” at “Instituto de Nanociencia de Aragon – Universidad de Zaragoza”. Authors acknowledge the LMA-INA for offering access to their instruments and expertise. Authors would like to acknowledge the use of Servicio General de Apoyo a la Investigacion-SAI, Universidad de Zaragoza, particularly the Servicio de Medidas Fisicas. We also acknowledge the computer resources and assistance provided by the Centro de Computacion Cientifica of the Universidad Autonoma de Madrid. ; Approved Most recent IF: 4.259
Call Number UA @ admin @ c:irua:162868 Serial 5420
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Author Menezes, R.M.; Neto, J.F.S.; de Souza Silva, C.C.; Milošević, M.V.
Title Manipulation of magnetic skyrmions by superconducting vortices in ferromagnet-superconductor heterostructures Type (up) A1 Journal article
Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 100 Issue 1 Pages 014431
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Dynamics of magnetic skyrmions in hybrid ferromagnetic films harbors interesting physical phenomena and holds promise for technological applications. In this work, we discuss the behavior of magnetic skyrmions when coupled to superconducting vortices in a ferromagnet-superconductor heterostructure. We use numerical simulations and analytic arguments within London and Thiele formalisms to reveal broader possibilities for manipulating the skyrmion-vortex dynamic correlations in the hybrid system, that are not possible in its separated constituents. We explore the thresholds of particular dynamic phases, and quantify the phase diagram as a function of the relevant material parameters, applied current, and induced magnetic torques. Finally, we demonstrate the broad and precise tunability of the skyrmion Hall angle in the presence of vortices, with respect to currents applied to either or both the superconductor and the ferromagnet within the heterostructure.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000477883500004 Publication Date 2019-07-29
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 17 Open Access
Notes ; This work was supported by the Research Foundation – Flanders (FWO-Vlaanderen) and Brazilian Agencies Fundacao de Amparo a Ciencia e Tecnologia do Estado de Pernambuco (FACEPE, under Grant No. APQ-0198-1.05/14), Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES), and Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq). ; Approved Most recent IF: 3.836
Call Number UA @ admin @ c:irua:161890 Serial 5421
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Author Xue, C.; He, A.; Milošević, M.V.; Silhanek, A., V; Zhou, Y.-H.
Title Open circuit voltage generated by dragging superconducting vortices with a dynamic pinning potential Type (up) A1 Journal article
Year 2019 Publication New journal of physics Abbreviated Journal New J Phys
Volume 21 Issue 11 Pages 113044
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We theoretically investigate, through Ginzburg?Landau simulations, the possibility to induce an open circuit voltage in absence of applied current, by dragging superconducting vortices with a dynamic pinning array as for instance that created by a nearby sliding vortex lattice or moving laser spots. Different dynamic regimes, such as synchronous vortex motion or dynamic vortex chains consisting of laggard vortices, can be observed by varying the velocity of the sliding pinning potential and the applied magnetic field. Additionally, due to the edge barrier, significantly different induced voltage is found depending on whether the vortices are dragged along the superconducting strip or perpendicular to the lateral edges. The output voltage in the proposed mesoscopic superconducting dynamo can be tuned by varying size, density and directions of the sliding pinning potential.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000498853700001 Publication Date 2019-11-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1367-2630 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.786 Times cited 6 Open Access
Notes Approved Most recent IF: 3.786
Call Number UA @ admin @ c:irua:165158 Serial 6317
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Author Gonzalez-Garcia, A.; Lopez-Perez, W.; Gonzalez-Hernandez, R.; Rivera-Julio, J.; Espejo, C.; Milošević, M.V.; Peeters, F.M.
Title Two-dimensional hydrogenated buckled gallium arsenide: an ab initio study Type (up) A1 Journal article
Year 2020 Publication Journal Of Physics-Condensed Matter Abbreviated Journal J Phys-Condens Mat
Volume 32 Issue 14 Pages 145502
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract First-principles calculations have been carried out to investigate the stability, structural and electronic properties of two-dimensional (2D) hydrogenated GaAs with three possible geometries: chair, zigzag-line and boat configurations. The effect of van der Waals interactions on 2D H-GaAs systems has also been studied. These configurations were found to be energetic and dynamic stable, as well as having a semiconducting character. Although 2D GaAs adsorbed with H tends to form a zigzag-line configuration, the energy differences between chair, zigzag-line and boat are very small which implies the metastability of the system. Chair and boat configurations display a – direct bandgap nature, while pristine 2D-GaAs and zigzag-line are indirect semiconductors. The bandgap sizes of all configurations are also hydrogen dependent, and wider than that of pristine 2D-GaAs with both PBE and HSE functionals. Even though DFT-vdW interactions increase the adsorption energies and reduce the equilibrium distances of H-GaAs systems, it presents, qualitatively, the same physical results on the stability and electronic properties of our studied systems with PBE functional. According to our results, 2D buckled gallium arsenide is a good candidate to be synthesized by hydrogen surface passivation as its group III-V partners 2D buckled gallium nitride and boron nitride. The hydrogenation of 2D-GaAs tunes the bandgap of pristine 2D-GaAs, which makes it a potential candidate for optoelectronic applications in the blue and violet ranges of the visible electromagnetic spectrum.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000507894400001 Publication Date 2019-12-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984 ISBN Additional Links UA library record; WoS full record
Impact Factor 2.7 Times cited Open Access
Notes ; This work has been carried out by the financial support of Universidad del Norte and Colciencias (Administrative Department of Science, Technology and Research of Colombia) under Convocatoria 712-Convocatoria para proyectos de investigacion en Ciencias Basicas, ano 2015, Cod: 121571250192, Contrato 110-216. The authors gratefully acknowledge the support from the High Performance Computing core facility CalcUA and the TOPBOF project at the University of Antwerp, Belgium; and the computing time granted on the supercomputer Mogon at Johannes Gutenberg University Mainz (hpc.uni-mainz.de). ; Approved Most recent IF: 2.7; 2020 IF: 2.649
Call Number UA @ admin @ c:irua:165644 Serial 6330
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Author Vanherck, J.; Bacaksiz, C.; Sorée, B.; Milošević, M.V.; Magnus, W.
Title 2D ferromagnetism at finite temperatures under quantum scrutiny Type (up) A1 Journal article
Year 2020 Publication Applied Physics Letters Abbreviated Journal Appl Phys Lett
Volume 117 Issue 5 Pages 052401
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Recent years have seen a tremendous rise of two-dimensional (2D) magnetic materials, several of which were verified experimentally. However, most of the theoretical predictions to date rely on ab initio methods, at zero temperature and fluctuation-free, while one certainly expects detrimental quantum fluctuations at finite temperatures. Here, we present the solution of the quantum Heisenberg model for honeycomb/hexagonal lattices with anisotropic exchange interaction up to third nearest neighbors and in an applied field in arbitrary direction, which answers the question whether long-range magnetization can indeed survive in the ultrathin limit of materials, up to which temperature, and what the characteristic excitation (magnon) frequencies are, all essential to envisaged applications of magnetic 2D materials. We find that long-range magnetic order persists at finite temperature for materials with overall easy-axis anisotropy. We validate the calculations on the examples of monolayers CrI3, CrBr3, and MnSe2. Moreover, we provide an easy-to-use tool to calculate Curie temperatures of new 2D computational materials.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000559330100001 Publication Date 2020-08-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; 1077-3118 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4 Times cited 8 Open Access
Notes ; This work was supported by the Research Foundation-Flanders (FWO) and the special research funds of the University of Antwerp (BOF-UA). ; Approved Most recent IF: 4; 2020 IF: 3.411
Call Number UA @ admin @ c:irua:171176 Serial 6445
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Author Sabani, D.; Bacaksiz, C.; Milošević, M.V.
Title Ab initio methodology for magnetic exchange parameters: Generic four-state energy mapping onto a Heisenberg spin Hamiltonian Type (up) A1 Journal article
Year 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 102 Issue 1 Pages 014457-14458
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The recent development in the field of two-dimensional magnetic materials urges reliable theoretical methodology for determination of magnetic properties. Among the available methods, ab initio four-state energy mapping based on density functional theory stands out as a powerful technique to calculate the magnetic exchange interaction in the Heisenberg spin model. Although the required formulas were explained in earlier works, the considered Hamiltonian in those studies always corresponded to the specific case that the off-diagonal part of J matrix is antisymmetric, which may be misleading in other cases. Therefore, using the most general form of the Heisenberg spin Hamiltonian, we here derive the generic formulas. With a proper choice of four different magnetic states, a single formula governs all elements of the exchange interaction matrix for any considered pair of spin sites.
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Publisher Place of Publication Editor
Language Wos 000554409500002 Publication Date 2020-07-31
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 3.7 Times cited 13 Open Access
Notes ; This work was supported by the Research Foundation-Flanders (FWO-Vlaanderen) and the Special Research Funds of the University of Antwerp (TOPBOF). The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Research Foundation-Flanders (FWO-Vlaanderen) and the Flemish Government, Department EWI. ; Approved Most recent IF: 3.7; 2020 IF: 3.836
Call Number UA @ admin @ c:irua:171203 Serial 6448
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Author McNaughton, B.; Milošević, M.V.; Perali, A.; Pilati, S.
Title Boosting Monte Carlo simulations of spin glasses using autoregressive neural networks Type (up) A1 Journal article
Year 2020 Publication Physical Review E Abbreviated Journal Phys Rev E
Volume 101 Issue 5 Pages 053312
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The autoregressive neural networks are emerging as a powerful computational tool to solve relevant problems in classical and quantum mechanics. One of their appealing functionalities is that, after they have learned a probability distribution from a dataset, they allow exact and efficient sampling of typical system configurations. Here we employ a neural autoregressive distribution estimator (NADE) to boost Markov chain Monte Carlo (MCMC) simulations of a paradigmatic classical model of spin-glass theory, namely, the two-dimensional Edwards-Anderson Hamiltonian. We show that a NADE can be trained to accurately mimic the Boltzmann distribution using unsupervised learning from system configurations generated using standard MCMC algorithms. The trained NADE is then employed as smart proposal distribution for the Metropolis-Hastings algorithm. This allows us to perform efficient MCMC simulations, which provide unbiased results even if the expectation value corresponding to the probability distribution learned by the NADE is not exact. Notably, we implement a sequential tempering procedure, whereby a NADE trained at a higher temperature is iteratively employed as proposal distribution in a MCMC simulation run at a slightly lower temperature. This allows one to efficiently simulate the spin-glass model even in the low-temperature regime, avoiding the divergent correlation times that plague MCMC simulations driven by local-update algorithms. Furthermore, we show that the NADE-driven simulations quickly sample ground-state configurations, paving the way to their future utilization to tackle binary optimization problems.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000535862000014 Publication Date 2020-05-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1539-3755; 1550-2376 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.366 Times cited 15 Open Access
Notes ; The authors thank I. Murray, G. Carleo, and F. RicciTersenghi for useful discussions. Financial support from the FAR2018 project titled “Supervised machine learning for quantum matter and computational docking” of the University of Camerino and from the Italian MIUR under Project No. PRIN2017 CEnTraL 20172H2SC4 is gratefully acknowledged. S.P. also acknowledges the CINECA award under the ISCRA initiative, for the availability of high performance computing resources and support. M.V.M. gratefully acknowledges the Visiting Professorship program at the University of Camerino that facilitated the collaboration in this work. ; Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:170244 Serial 6463
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