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Author Zebrowski, D.P.; Peeters, F.M.; Szafran, B.
Title Double quantum dots defined in bilayer graphene Type A1 Journal article
Year 2017 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 96 Issue 3 Pages (down) 035434
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Artificial molecular states of double quantum dots defined in bilayer graphene are studied with the atomistic tight-binding method and its low-energy continuum approximation. We indicate that the extended electron wave functions have opposite parities on sublattices of the layers and that the ground-state wave-function components change from bonding to antibonding with the interdot distance. In the weak-coupling limit, the one most relevant for quantum dots defined electrostatically, the signatures of the interdot coupling include, for the two-electron ground state, formation of states with symmetric or antisymmetric spatial wave functions split by the exchange energy. In the high-energy part of the spectrum the states with both electrons in the same dot are found with the splitting of energy levels corresponding to simultaneous tunneling of the electron pair from one dot to the other.
Address
Corporate Author Thesis
Publisher American Physical Society Place of Publication New York, N.Y Editor
Language Wos 000406284200005 Publication Date 2017-07-26
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 6 Open Access
Notes ; ; Approved Most recent IF: 3.836
Call Number UA @ lucian @ c:irua:145758 Serial 4739
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Author Wang, J.; Van Pottelberge, R.; Zhao, W.-S.; Peeters, F.M.
Title Coulomb impurity on a Dice lattice : atomic collapse and bound states Type A1 Journal article
Year 2022 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 105 Issue 3 Pages (down) 035427
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The modification of the quantum states in a Dice lattice due to a Coulomb impurity are investigated. The energy-band structure of a pristine Dice lattice consists of a Dirac cone and a flat band at the Dirac point. We use the tight-binding formalism and find that the flat band states transform into a set of discrete bound states whose electron density is localized on a ring around the impurity mainly on two of the three sublattices. Its energy is proportional to the strength of the Coulomb impurity. Beyond a critical strength of the Coulomb potential atomic collapse states appear that have some similarity with those found in graphene with the difference that the flat band states contribute with an additional ringlike electron density that is spatially decoupled from the atomic collapse part. At large value of the strength of the Coulomb impurity the flat band bound states anticross with the atomic collapse states.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000749375200002 Publication Date 2022-01-28
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 1 Open Access Not_Open_Access
Notes Approved Most recent IF: 3.7
Call Number UA @ admin @ c:irua:186387 Serial 6977
Permanent link to this record
 
 
Author Wang, J.; Van Pottelberge, R.; Jacobs, A.; Van Duppen, B.; Peeters, F.M.
Title Confinement and edge effects on atomic collapse in graphene nanoribbons Type A1 Journal article
Year 2021 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 103 Issue 3 Pages (down) 035426
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Atomic collapse in graphene nanoribbons behaves in a fundamentally different way as compared to monolayer graphene due to the presence of multiple energy bands and the effect of edges. For armchair nanoribbons we find that bound states gradually transform into atomic collapse states with increasing impurity charge. This is very different in zigzag nanoribbons where multiple quasi-one-dimensional bound states are found that originates from the zero-energy zigzag edge states. They are a consequence of the flat band and the electron distribution of these bound states exhibits two peaks. The lowest-energy edge state transforms from a bound state into an atomic collapse resonance and shows a distinct relocalization from the edge to the impurity position with increasing impurity charge.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000610779200008 Publication Date 2021-01-22
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 OpenAccess
Notes Approved Most recent IF: 3.836
Call Number UA @ admin @ c:irua:176585 Serial 6719
Permanent link to this record
 
 
Author Sabzalipour, A.; Partoens, B.
Title Anomalous Hall effect in magnetic topological insulators : semiclassical framework Type A1 Journal article
Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 100 Issue 3 Pages (down) 035419
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The anomalous Hall effect (AHE) is studied on the surface of a 3D magnetic topological insulator. By applying a modified semiclassical framework, all three contributions to the AHE, the Berry curvature effect, the side jump effect and the skew scattering effects are systematically treated, and analytical expressions for the conductivities are obtained in terms of the Fermi level, the spatial orientation of the surface magnetization and the concentration of magnetic and nonmagnetic impurities. We demonstrate that the AHE can change sign by altering the orientation of the surface magnetization, the concentration of the impurities and also the position of the Fermi level, in agreement with recent experimental observations. We show how each contribution to the AHE, or even the whole AHE, can be turned off by properly adjusting the given parameters. For example, one can turn off the anomalous hall conductivity in a system with in-plane magnetization by pushing the system into the fully metallic regime.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000475499200007 Publication Date 2019-07-15
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 2 Open Access
Notes ; ; Approved Most recent IF: 3.836
Call Number UA @ admin @ c:irua:161219 Serial 5406
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Author da Costa; Zarenia, M.; Chaves, A.; Pereira, J.M., Jr.; Farias, G.A.; Peeters, F.M.
Title Hexagonal-shaped monolayer-bilayer quantum disks in graphene : a tight-binding approach Type A1 Journal article
Year 2016 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 94 Issue 94 Pages (down) 035415
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using the tight-binding approach, we investigate confined states in two different hybrid monolayer-bilayer systems: (i) a hexagonal monolayer area surrounded by bilayer graphene in the presence of a perpendicularly applied electric field and (ii) a hexagonal bilayer graphene dot surrounded by monolayer graphene. The dependence of the energy levels on dot size and external magnetic field is calculated. We find that the energy spectrum for quantum dots with zigzag edges consists of states inside the gap which range from dot-localized states, edge states, to mixed states coexisting together, whereas for dots with armchair edges, only dot-localized states are observed.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000379502200008 Publication Date 2016-07-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9950;2469-9969; 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 financially supported by CNPq, under contract NanoBioEstruturas No. 555183/2005-0, PRONEX/FUNCAP, CAPES Foundation, under the process No. BEX 7178/13-1, the Flemish Science Foundation (FWO-Vl), the Bilateral programme between CNPq and FWO-Vl, the Brazilian Program Science Without Borders (CsF), and the Lemann Foundation. ; Approved Most recent IF: 3.836
Call Number UA @ lucian @ c:irua:134947 Serial 4190
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Author Mobaraki, A.; Sevik, C.; Yapicioglu, H.; Cakir, D.; Gulseren, O.
Title Temperature-dependent phonon spectrum of transition metal dichalcogenides calculated from the spectral energy density: Lattice thermal conductivity as an application Type A1 Journal article
Year 2019 Publication Physical review B Abbreviated Journal
Volume 100 Issue 3 Pages (down) 035402
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Predicting the mechanical and thermal properties of quasi-two-dimensional (2D) transition metal dichalco-genides (TMDs) is an essential task necessary for their implementation in device applications. Although rigorous density-functional-theory-based calculations are able to predict mechanical and electronic properties, mostly they are limited to zero temperature. Classical molecular dynamics facilitates the investigation of temperature-dependent properties, but its performance highly depends on the potential used for defining interactions between the atoms. In this study, we calculated temperature-dependent phonon properties of single-layer TMDs, namely, MoS2, MoSe2, WS2, and WSe2, by utilizing Stillinger-Weber-type potentials with optimized sets of parameters with respect to the first-principles results. The phonon lifetimes and contribution of each phonon mode in thermal conductivities in these monolayer crystals are systematically investigated by means of the spectralenergy-density method based on molecular dynamics simulations. The obtained results from this approach are in good agreement with previously available results from the Green-Kubo method. Moreover, detailed analysis of lattice thermal conductivity, including temperature-dependent mode decomposition through the entire Brillouin zone, shed more light on the thermal properties of these 2D crystals. The LA and TA acoustic branches contribute most to the lattice thermal conductivity, while ZA mode contribution is less because of the quadratic dispersion around the Brillouin zone center, particularly in MoSe2 due to the phonon anharmonicity, evident from the redshift, especially in optical modes, by increasing temperature. For all the considered 2D crystals, the phonon lifetime values are compelled by transition metal atoms, whereas the group velocity spectrum is dictated by chalcogen atoms. Overall, the lattice thermal conductivity is linearly proportional with inverse temperature.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000473536400003 Publication Date 2019-07-02
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 Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:193764 Serial 8645
Permanent link to this record
 
 
Author Miranda, L.P.; Milovanović, S.P.; Filho, R.N.C.; Peeters, F.M.
Title Hall and bend resistance of a phosphorene Hall bar Type A1 Journal article
Year 2021 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 104 Issue 3 Pages (down) 035401
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The dependence of the Hall and bend resistances on a perpendicular magnetic field and on vacancy defects in a four-terminal phosphorene single layer Hall bar is investigated. A tight-binding model in combination with the Landauer-Buttiker formalism is used to calculate the energy spectrum, the lead-to-lead transmissions, and the Hall and bend resistances of the system. It is shown that the terminals with zigzag edge orientation are responsible for the absence of quantized plateaus in the Hall resistance and peaks in the longitudinal resistance. A negative bend resistance in the ballistic regime is found due to the presence of high- and low-energy transport modes in the armchair and zigzag terminals, respectively. The system density of states, with single vacancy defects, shows that the presence of in-gap states is proportional to the number of vacancies. Quantized plateaus in the Hall resistance are only formed in a sufficiently clean system. The effects of different kinds of vacancies where the plateaus are destroyed and a diffusive regime appears in the bend resistance are investigated.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000669002000003 Publication Date 2021-07-01
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 2 Open Access OpenAccess
Notes Approved Most recent IF: 3.836
Call Number UA @ admin @ c:irua:179704 Serial 6997
Permanent link to this record
 
 
Author Dharma-Wardana, M.W.C.; Neilson, D.; Peeters, F.M.
Title Correlation functions in electron-electron and electron-hole double quantum wells : temperature, density, and barrier-width dependence Type A1 Journal article
Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 99 Issue 3 Pages (down) 035303
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The classical-map hypernetted-chain (CHNC) scheme, developed for treating fermion fluids at strong coupling and at finite temperatures, is applied to electron-electron and electron-hole double quantum wells. The pair-distribution functions and the local field factors needed in linear-response theory are determined for a range of temperatures, carrier densities, and barrier widths typical for experimental double-quantum-well systems in GaAs-GaAlAs. For electron-hole double quantum wells, a large enhancement in the pair-distribution functions is found for small carrier separations. The CHNC equations for electron-hole systems no longer hold at low densities where bound-state formation occurs.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000455163800004 Publication Date 2019-01-08
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 6 Open Access
Notes ; This work was partially supported by the Flemish Science Foundation (FWO-Vl). M.W.C.D.-W. acknowledges with thanks the hospitality and stimulating atmosphere of the Condensed Matter Theory group at the University of Antwerp. ; Approved Most recent IF: 3.836
Call Number UA @ admin @ c:irua:156734 Serial 5201
Permanent link to this record
 
 
Author Santos-Castro, G.; Pandey, T.; Bruno, C.H.V.; Santos Caetano, E.W.; Milošević, M.V.; Chaves, A.; Freire, V.N.
Title Silicon and germanium adamantane and diamantane monolayers as two-dimensional anisotropic direct-gap semiconductors Type A1 Journal article
Year 2023 Publication Physical review B Abbreviated Journal
Volume 108 Issue 3 Pages (down) 035302-35310
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Structural and electronic properties of silicon and germanium monolayers with two different diamondoid crystal structures are detailed ab initio. Our results show that, despite Si and Ge being well-known indirect gap semiconductors in their bulk form, their adamantane and diamantane monolayers can exhibit optically active direct gap in the visible frequency range, with highly anisotropic effective masses, depending on the monolayer crystal structure. Moreover, we reveal that gaps in these materials are highly tunable with applied strain. These stable monolayer forms of Si and Ge are therefore expected to help bridging the gap between the fast growing area of opto-electronics in two-dimensional materials and the established silicon-based technologies.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001074455300012 Publication Date 2023-07-05
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
Impact Factor 3.7 Times cited Open Access
Notes Approved Most recent IF: 3.7; 2023 IF: 3.836
Call Number UA @ admin @ c:irua:200348 Serial 9089
Permanent link to this record
 
 
Author Van der Donck, M.; Zarenia, M.; Peeters, F.M.
Title Excitons and trions in monolayer transition metal dichalcogenides : a comparative study between the multiband model and the quadratic single-band model Type A1 Journal article
Year 2017 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 96 Issue 3 Pages (down) 035131
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The electronic and structural properties of excitons and trions in monolayer transition metal dichalcogenides are investigated using both a multiband and a single- band model. In the multiband model we construct the excitonic Hamiltonian in the product base of the single-particle states at the conduction and valence band edges. We decouple the corresponding energy eigenvalue equation and solve the resulting differential equation self-consistently, using the finite element method (FEM), to determine the energy eigenvalues and the wave functions. As a comparison, we also consider the simple single-band model which is often used in numerical studies. We solve the energy eigenvalue equation using the FEM as well as with the stochastic variational method (SVM) in which a variational wave function is expanded in a basis of a large number of correlated Gaussians. We find good agreement between the results of both methods, as well as with other theoretical works for excitons, and we also compare with available experimental data. For trions the agreement between both methods is not as good due to our neglect of angular correlations when using the FEM. Finally, when comparing the two models, we see that the presence of the valence bands in the mutiband model leads to differences with the single- band model when (interband) interactions are strong.
Address
Corporate Author Thesis
Publisher American Physical Society Place of Publication New York, N.Y Editor
Language Wos 000405706600005 Publication Date 2017-07-18
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 50 Open Access
Notes ; This work was supported by the Research Foundation of Flanders (FWO-Vl) through an aspirant research grant for MVDD. ; Approved Most recent IF: 3.836
Call Number UA @ lucian @ c:irua:145209 Serial 4716
Permanent link to this record
 
 
Author Kong, X.; Li, L.; Leenaerts, O.; Liu, X.-J.; Peeters, F.M.
Title New group-V elemental bilayers : a tunable structure model with four-, six-, and eight-atom rings Type A1 Journal article
Year 2017 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 96 Issue 3 Pages (down) 035123
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Two-dimensional group-V elemental materials have attracted widespread attention due to their nonzero band gap while displaying high electron mobility. Using first-principles calculations, we propose a series of new elemental bilayers with group-V elements (Bi, Sb, As). Our study reveals the dynamical stability of four-, six-, and eight-atom ring structures, demonstrating their possible coexistence in such bilayer systems. The proposed structures for Sb and As are large-gap semiconductors that are potentially interesting for applications in future nanodevices. The Bi structures have nontrivial topological properties with a direct nontrivial band gap. The nontrivial gap is shown to arise from a band inversion at the Brillouin zone center due to the strong intrinsic spin-orbit coupling in Bi atoms. Moreover, we demonstrate the possibility of tuning the properties of these materials by enhancing the ratio of six-atom rings to four-and eight-atom rings, which results in wider nontrivial band gaps and lower formation energies.
Address
Corporate Author Thesis
Publisher American Physical Society Place of Publication New York, N.Y Editor
Language Wos 000405363900005 Publication Date 2017-07-14
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 14 Open Access
Notes ; This work is supported by Ministry of Science and Technology of China (MOST) (Grant No. 2016YFA0301604), National Natural Science Foundation of China (NSFC) ( No. 11574008), the Thousand-Young-Talent Program of China, and the Fonds voor Wetenschappelijk Onderzoek (FWO-Vl). 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, and the National Supercomputing Center in Tianjin, funded by the Collaborative Innovation Center of Quantum Matter. ; Approved Most recent IF: 3.836
Call Number UA @ lucian @ c:irua:144834 Serial 4721
Permanent link to this record
 
 
Author Shafiei, M.; Fazileh, F.; Peeters, F.M.; Milošević, M.V.
Title Controlling the hybridization gap and transport in a thin-film topological insulator : effect of strain, and electric and magnetic field Type A1 Journal article
Year 2022 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 106 Issue 3 Pages (down) 035119-7
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract In a thin-film topological insulator (TI), the edge states on two surfaces may couple by quantum tunneling, opening a gap known as the hybridization gap. Controlling the hybridization gap and transport has a variety of potential uses in photodetection and energy-harvesting applications. In this paper, we report the effect of strain, and electric and magnetic field, on the hybridization gap and transport in a thin Bi2Se3 film, investigated within the tight-binding theoretical framework. We demonstrate that vertical compression decreases the hybridization gap, as does tensile in-plane strain. Applying an electric field breaks the inversion symmetry and leads to a Rashba-like spin splitting proportional to the electric field, hence closing and reopening the gap. The influence of a magnetic field on thin-film TI is also discussed, starting from the role of an out-of-plane magnetic field on quantum Hall states. We further demonstrate that the hybridization gap can be controlled by an in-plane magnetic field, and that by applying a sufficiently strong field a quantum phase transition from an insulator to a semimetal can be achieved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000832277500001 Publication Date 2022-07-13
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 3.7 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 3.7
Call Number UA @ admin @ c:irua:189515 Serial 7140
Permanent link to this record
 
 
Author Zhang, L.; Fernández Becerra, V.; Covaci, L.; Milošević, M.V.
Title Electronic properties of emergent topological defects in chiral p-wave superconductivity Type A1 Journal article
Year 2016 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 94 Issue 94 Pages (down) 024520
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Chiral p-wave superconductors in applied magnetic field can exhibit more complex topological defects than just conventional superconducting vortices, due to the two-component order parameter (OP) and the broken time-reversal symmetry. We investigate the electronic properties of those exotic states, some of which contain clusters of one-component vortices in chiral components of the OP and/or exhibit skyrmionic character in the relative OP space, all obtained as a self-consistent solution of the microscopic Bogoliubov-de Gennes equations. We reveal the link between the local density of states (LDOS) of the novel topological states and the behavior of the chiral domain wall between the OP components, enabling direct identification of those states in scanning tunneling microscopy. For example, a skyrmion always contains a closed chiral domain wall, which is found to be mapped exactly by zero-bias peaks in LDOS. Moreover, the LDOS exhibits electron-hole asymmetry, which is different from the LDOS of conventional vortex states with same vorticity. Finally, we present the magnetic field and temperature dependence of the properties of a skyrmion, indicating that this topological defect can be surprisingly large in size, and can be pinned by an artificially indented nonsuperconducting closed path in the sample. These features are expected to facilitate the experimental observation of skyrmionic states, thereby enabling experimental verification of chirality in emerging superconducting materials.
Address
Corporate Author Thesis
Publisher American Physical Society Place of Publication New York, N.Y Editor
Language Wos 000381479500002 Publication Date 2016-07-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9969 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 27 Open Access
Notes ; This work was supported by the Fonds Wetenschappelijk Onderzoek (FWO). ; Approved Most recent IF: 3.836
Call Number UA @ lucian @ c:irua:135742 Serial 4303
Permanent link to this record
 
 
Author Zhao, H.J.; Wu, W.; Zhou, W.; Shi, Z.X.; Misko, V.R.; Peeters, F.M.
Title Reentrant dynamics of driven pancake vortices in layered superconductors Type A1 Journal article
Year 2016 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 94 Issue 94 Pages (down) 024514
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The dynamics of driven pancake vortices in layered superconductors is studied using molecular-dynamics simulations. We found that, with increasing driving force, for strong interlayer coupling, the preexisted vortex lines either directly depin or first transform to two-dimensional (2D) pinned states before they are depinned, depending on the pinning strength. In a narrow region of pinning strengths, we found an interesting repinning process, which results in a negative differential resistance. For weak interlayer coupling, individually pinned pancake vortices first form disordered 2D flow and then transform to ordered three-dimensional (3D) flow with increasing driving force. However, for extremely strong pinning, the random pinning-induced thermal-like Langevin forces melt 3D vortex lines, which results in a persistent 2D flow in the fast-sliding regime. In the intermediate regime, the peak effect is found: With increasing driving force, the moving pancake vortices first crystallize to moving 3D vortex lines, and then these 3D vortex lines are melted, leading to the appearance of a reentrant 2D flow state. Our results are summarized in a dynamical phase diagram.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000380097800006 Publication Date 2016-07-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9950;2469-9969; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 3 Open Access
Notes ; We acknowledge useful discussions with C. Olson Reichhardt. This work was supported by the Natural Science Foundation of Jiangsu Province (Grant No. BK20150595), National Natural Science Foundation of China (Grants No. NSFC-U1432135 and No. 11611140101). V.R.M. acknowledges support from the “Odysseus” program of the Flemish Government and Flemish Science Foundation (FWO-Vl), the FWO-Vl, and the Research Fund of the University of Antwerp. ; Approved Most recent IF: 3.836
Call Number UA @ lucian @ c:irua:134943 Serial 4238
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Author Behera, B.C.; Jana, S.; Bhat, S.G.; Gauquelin, N.; Tripathy, G.; Kumar, P.S.A.; Samal, D.
Title Evidence for exchange bias coupling at the perovskite/brownmillerite interface in spontaneously stabilized SrCoO3-\delta/SrCoO2.5 bilayers Type A1 Journal article
Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 99 Issue 2 Pages (down) 024425
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Interface effect in complex oxide thin-film heterostructures lies at the vanguard of current research to design technologically relevant functionality and explore emergent physical phenomena. While most of the previous works focus on the perovskite/perovskite heterostructures, the study of perovskite/brownmillerite interfaces remains in its infancy. Here, we investigate spontaneously stabilized perovskite-ferromagnet (SrCoO3-delta)/brownmillerite-antiferromagnet (SrCoO2.5) bilayer with T-N > T-C and discover an unconventional interfacial magnetic exchange bias effect. From magnetometry investigations, it is rationalized that the observed effect stems from the interfacial ferromagnet/antiferromagnet coupling. The possibility for coupled ferromagnet/spin-glass interface engendering such effect is ruled out. Strikingly, a finite coercive field persists in the paramagnetic state of SrCoO3-delta,whereas the exchange bias field vanishes at T-C . We conjecture the observed effect to be due to the effective external quenched staggered field provided by the antiferromagnetic layer for the ferromagnetic spins at the interface. Our results not only unveil a paradigm to tailor the interfacial magnetic properties in oxide heterostructures without altering the cations at the interface, but also provide a purview to delve into the fundamental aspects of exchange bias in such unusual systems, paving a big step forward in thin-film magnetism.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000456481900003 Publication Date 2019-01-23
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 2 Open Access OpenAccess
Notes ; We are grateful to Sachin Sarangi for his superb technical support during magnetic measurements. We thank Gopal Pradhan for fruitful discussion. We thank Zhicheng Zhong for reading the manuscript and for suggestions. We thank T. Som for extending laboratory facility. D.S. and B.C.B. acknowledge the financial support from Max-Planck Society through Max Planck Partner Group. S.G.B. acknowledges the INSPIRE Faculty Fellowship Programme (DSTO1899) for the financial support. ; Approved Most recent IF: 3.836
Call Number UA @ admin @ c:irua:157562 Serial 5248
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Author Das, S.; Rata, A.D.; Maznichenko, I., V; Agrestini, I.S.; Pippel, E.; Gauquelin, N.; Verbeeck, J.; Chen, K.; Valvidares, S.M.; Vasili, H.B.; Herrero-Martin, J.; Pellegrin, E.; Nenkov, K.; Herklotz, A.; Ernst, A.; Mertig, I.; Hu, Z.; Doerr, K.
Title Low-field switching of noncollinear spin texture at La0.7Sr0.3MnO3-SrRuO3interfaces Type A1 Journal article
Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 99 Issue 2 Pages (down) 024416
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Interfaces of ferroic oxides can show complex magnetic textures which have strong impact on spintronics devices. This has been demonstrated recently for interfaces with insulating antiferromagnets such as BiFeO3. Here, noncollinear spin textures which can be switched in very low magnetic field are reported for conducting ferromagnetic bilayers of La0.7Sr0.3MnO3-SrRuO3 (LSMO-SRO). The magnetic order and switching are fundamentally different for bilayers coherently grown in reversed stacking sequence. The SRO top layer forms a persistent exchange spring which is antiferromagnetically coupled to LSMO and drives switching in low fields of a few milliteslas. Density functional theory reveals the crucial impact of the interface termination on the strength of Mn-Ru exchange coupling across the interface. The observation of an exchange spring agrees with ultrastrong coupling for the MnO2/SrO termination. Our results demonstrate low-field switching of noncollinear spin textures at an interface between conducting oxides, opening a pathway for manipulating and utilizing electron transport phenomena in controlled spin textures at oxide interfaces.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000455821400005 Publication Date 2019-01-15
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 OpenAccess
Notes ; The research in Halle was supported by Deutsche Forschungsgemeinschaft (DFG), SFB 762 Functional Oxide Interfaces (Projects No. A9 and No. B1). K.C. benefited from support of the DFG (Project 600575). Discussions with M. Trassin, M. Ziese, H. M. Christen, E.-J. Guo, F. Grcondciel, M. Bibes, and H. N. Lee are gratefully acknowledged. N. G. and J. V. acknowledge funding under the GOA project “Solarpaint” of the University of Antwerp. The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government. ; Approved Most recent IF: 3.836
Call Number UA @ admin @ c:irua:156717 Serial 5255
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Author Yu, Y.; Chen, X.; Liu, X.; Li, J.; Sanyal, B.; Kong, X.; Peeters, F.M.; Li, L.
Title Ferromagnetism with in-plane magnetization, Dirac spin-gapless semiconducting properties, and tunable topological states in two-dimensional rare-earth metal dinitrides Type A1 Journal article
Year 2022 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 105 Issue 2 Pages (down) 024407
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Since the successful synthesis of bulk single crystals MoN2 and ReN2, which have a layered structure, transition-metal dinitrides have attracted considerable attention in recent years. Here, we focus on rare-earth metal (Rem) elements, and propose seven stable Rem dinitride monolayers with a 1T structure, namely, 1T-RemN2. We use first-principles calculations, and find that these monolayers have a ferromagnetic ground state with in-plane magnetization. Without spin-orbit coupling (SOC), the band structures are spin-polarized with Dirac points at the Fermi level. Remarkably, the 1T-LuN2 monolayer exhibits an isotropic magnetocrystalline anisotropy energy in the xy plane with in-plane magnetization, indicating easy tunability of the magnetization direction. When rotating the magnetization vector in the xy plane, we propose a model that accurately describes the variation of the SOC band gap and the two possible topological states (Weyl-like semimetal and Chern insulator states) whose properties are tunable. The Weyl-like semimetal state is a critical point between the two Chern insulator states with opposite sign of the Chern numbers (+/- 1). The nontrivial band gap (up to 60.3 meV) and the Weyl-like semimetal state are promising for applications in spintronic devices.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000742384700001 Publication Date 2022-01-06
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 4 Open Access Not_Open_Access: Available from 06.07.2202
Notes Approved Most recent IF: 3.7
Call Number UA @ admin @ c:irua:186514 Serial 6991
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Author Yagmurcukardes, M.
Title Monolayer fluoro-InSe : formation of a thin monolayer via fluorination of InSe Type A1 Journal article
Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 100 Issue 2 Pages (down) 024108
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract By performing density functional theory-based first-principles calculations, the formation of a thin monolayer structure, namely InSeF, via fluorination of monolayer InSe is predicted. It is shown that strong interaction of F and In atoms leads to the detachment of In-Se layers in monolayer InSe and 1T-like monolayer InSeF structure is formed. Monolayer InSeF is found to be dynamically stable in terms of its phonon band dispersions. In addition, its Raman spectrum is shown to exhibit totally distinctive features as compared to monolayer InSe. The electronic band dispersions reveal that monolayer InSeF is a direct gap semiconductor whose valence and conduction band edges reside at the Gamma point. Moreover, the orientation-dependent linear elastic properties of monolayer InSeF are investigated in terms of the in-plane stiffness and Poisson ratio. It is found that monolayer InSeF displays strong in-plane anisotropy in elastic constants and it is slightly softer material as compared to monolayer InSe. Overall, it is proposed that a thin, direct gap semiconducting monolayer InSeF can be formed by full fluorination of monolayer InSe as a new member of the two-dimensional family.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000477885700003 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 9 Open Access
Notes ; Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). This work is supported by the Flemish Science Foundation (FWO-Vl) by a postdoctoral fellowship (M.Y.). ; Approved Most recent IF: 3.836
Call Number UA @ admin @ c:irua:161891 Serial 5423
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Author Fernández Becerra, V.; Sardella, E.; Peeters, F.M.; Milošević, M.V.
Title Vortical versus skyrmionic states in mesoscopic p-wave superconductors Type A1 Journal article
Year 2016 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 93 Issue 93 Pages (down) 014518
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We investigate the superconducting states that arise as a consequence of mesoscopic confinement and a multicomponent order parameter in the Ginzburg-Landau model for p-wave superconductivity. Conventional vortices, but also half-quantum vortices and skyrmions, are found as the applied magnetic field and the anisotropy parameters of the Fermi surface are varied. The solutions are well differentiated by a topological charge that for skyrmions is given by the Hopf invariant and for vortices by the circulation of the superconducting velocity. We revealed several unique states combining vortices and skyrmions, their possible reconfiguration with varied magnetic field, as well as temporal and field-induced transitions between vortical and skyrmionic states.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000369217400004 Publication Date 2016-01-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9950;2469-9969; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 28 Open Access
Notes ; This work was supported by the Research Foundation – Flanders (FWO). E.S. acknowledges support from the Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP). ; Approved Most recent IF: 3.836
Call Number UA @ lucian @ c:irua:131581 Serial 4275
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Author Misko, V.R.; Fomin, V.M.; Devreese, J.T.
Title Strong enhancement of superconductivity in a nanosized Pb bridge Type A1 Journal article
Year 2001 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 64 Issue Pages (down) 014517,1-13
Keywords A1 Journal article; Electron Microscopy for Materials Science (EMAT);
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000169711900093 Publication Date 2002-07-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0163-1829;1095-3795; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 28 Open Access
Notes Approved Most recent IF: 3.836; 2001 IF: NA
Call Number UA @ lucian @ c:irua:34316 Serial 3181
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Author Moura, V.N.; Dantas, D.S.; Farias, G.A.; Chaves, A.; Milošević, M.V.
Title Latent superconductivity at parallel interfaces in a superlattice dominated by another collective quantum phase Type A1 Journal article
Year 2022 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 106 Issue 1 Pages (down) 014516-10
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We theoretically examine behavior of superconductivity at parallel interfaces separating the domains of another dominant collective excitation, such as charge density waves or spin density waves. Due to their competitive coupling in a two-component Ginzburg-Landau model, suppression of the dominant order parameter at the interfacial planes allows for nucleation of the (hidden) superconducting order parameter at those planes. In such a case, we demonstrate how the number of the parallel interfacial planes and the distance between them are linked to the number and the size of the emerging superconducting gaps in the system, as well as the versatility and temperature evolution of the possible superconducting phases. These findings bear relevance to a broad selection of known layered superconducting materials, as well as to further design of artificial (e.g., oxide) superlattices, where the interplay between competing order parameters paves the way towards otherwise unattainable superconducting states, some with enhanced superconducting critical temperature.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000834346000004 Publication Date 2022-07-22
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
Impact Factor 3.7 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 3.7
Call Number UA @ admin @ c:irua:189520 Serial 7179
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Author Covaci, L.; Marsiglio, F.
Title Proximity effect and Josephson current in clean strong/weak/strong superconducting trilayers Type A1 Journal article
Year 2006 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 73 Issue 1 Pages (down) 014503
Keywords A1 Journal article
Abstract Recent measurements of the Josephson critical current through LSCO/LCO/LSCO thin films showed an unusually large proximity effect. Using the Bogoliubov-de Gennes equations for a tight-binding Hamiltonian we describe the proximity effect in weak links between a superconductor with critical temperature T-c and one with critical temperature T-c('), where T-c > T-c('). The weak link (N-') is therefore a superconductor above its own critical temperature and the superconducting regions are considered to have either s-wave or d-wave symmetry. We note that the proximity effect is enhanced due to the presence of superconducting correlations in the weak link. The dc Josephson current is calculated, and we obtain a nonzero value for temperatures greater than T-c(') for sizes of the weak links that can be almost an order of magnitude greater than the conventional coherence length. Considering pockets of superconductivity in the N-' layer, we show that this can lead to an even larger effect on the Josephson critical current by effectively shortening the weak link.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000235009000103 Publication Date 2006-01-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121 ISBN Additional Links
Impact Factor 3.836 Times cited 31 Open Access
Notes Approved Most recent IF: 3.836; 2006 IF: 3.107
Call Number UA @ lucian @ Serial 4427
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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 (down) 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.'));
Address
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 Jiang, J.; Wang, Y.-L.; Milošević, M.V.; Xiao, Z.-L.; Peeters, F.M.; Chen, Q.-H.
Title Reversible ratchet effects in a narrow superconducting ring Type A1 Journal article
Year 2021 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 103 Issue 1 Pages (down) 014502
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We study the ratchet effect in a narrow pinning-free superconductive ring based on time-dependent Ginzburg-Landau (TDGL) equations. Voltage responses to external dc and ac currents at various magnetic fields are studied. Due to asymmetric barriers for flux penetration and flux exit in the ring-shaped superconductor, the critical current above which the flux-flow state is reached, as well as the critical current for the transition to the normal state, are different for the two directions of applied current. These effects cooperatively cause ratchet signal reversal at high magnetic fields, which has not been reported to date in a pinning-free system. The ratchet signal found here is larger than those induced by asymmetric pinning potentials. Our results also demonstrate the feasibility of using mesoscopic superconductors to employ a superconducting diode effect in versatile superconducting devices.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000604821500003 Publication Date 2021-01-05
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 2 Open Access OpenAccess
Notes ; We are grateful to G. Berdiyorov for useful suggestions and comments. Q.-H.C. thanks Beiyi Zhu for helpful discussions during the early stage of this work. This work is supported in part by the National Key Research and Development Program of China, Grants No. 2017YFA0303002 (Q.-H.C. and J.J.), and No. 2018YFA0209002 (Y.-L.W.), and the National Natural Science Foundation of China Grants No. 11834005, No. 11674285, No. 61771235, and No. 61727805. Z.-L.X. acknowledges support by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering and the National Science Foundation under Grant No. DMR-1901843. F.M.P. and M.V.M. acknowledge support by the Research Foundation – Flanders (FWO). ; Approved Most recent IF: 3.836
Call Number UA @ admin @ c:irua:174984 Serial 6697
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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 A1 Journal article
Year 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 102 Issue 1 Pages (down) 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.
Address
Corporate Author Thesis
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 Tiwari, S.; Van de Put, M.L.; Sorée, B.; Vandenberghe, W.G.
Title Critical behavior of the ferromagnets CrI₃, CrBr₃, and CrGeTe₃ and the antiferromagnet FeCl₂ : a detailed first-principles study Type A1 Journal article
Year 2021 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 103 Issue 1 Pages (down) 014432
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We calculate the Curie temperature of layered ferromagnets, chromium tri-iodide (CrI3), chromium tri-bromide (CrBr3), chromium germanium tri-telluride (CrGeTe3), and the Ned temperature of a layered antiferromagnet iron di-chloride (FeCl2), using first-principles density functional theory calculations and Monte Carlo simulations. We develop a computational method to model the magnetic interactions in layered magnetic materials and calculate their critical temperature. We provide a unified method to obtain the magnetic exchange parameters (J) for an effective Heisenberg Hamiltonian from first principles, taking into account both the magnetic ansiotropy as well as the out-of-plane interactions. We obtain the magnetic phase change behavior, in particular the critical temperature, from the susceptibility and the specific-heat, calculated using the three-dimensional Monte Carlo (METROPOLIS) algorithm. The calculated Curie temperatures for ferromagnetic materials (CrI3, CrBr3, and CrGeTe3), match well with experimental values. We show that the interlayer interaction in bulk CrI3 with R (3) over bar stacking is significantly stronger than the C2/m stacking, in line with experimental observations. We show that the strong interlayer interaction in R (3) over bar CrI3 results in a competition between the in-plane and the out-of-plane magnetic easy axes. Finally, we calculate the Ned temperature of FeCl2 to be 47 +/- 8 K and show that the magnetic phase transition in FeCl2 occurs in two steps with a high-temperature intralayer ferromagnetic phase transition and a low-temperature interlayer antiferromagnetic phase transition.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000609012000002 Publication Date 2021-01-20
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 Open Access OpenAccess
Notes ; The project or effort depicted was or is sponsored by the Department of Defense, Defense Threat Reduction Agency Grant No. HDTRA1-18-1-0018. The content of the information does not necessarily reflect the position or the policy of the federal government, and no official endorsement should be inferred. This work was supported by imec's Industrial Affiliation Program. ; Approved Most recent IF: 3.836
Call Number UA @ admin @ c:irua:176081 Serial 6686
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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 A1 Journal article
Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 100 Issue 1 Pages (down) 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 Wang, W.; Van Duppen, B.; Peeters, F.M.
Title Intense-terahertz-laser-modulated magnetopolaron effect on shallow-donor states in the presence of magnetic field in the Voigt configuration Type A1 Journal article
Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 99 Issue 1 Pages (down) 014114
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The laser-modulated magnetopolaron effect on shallow donors in semiconductors is investigated in the presence of a magnetic field in the Voigt configuration. A nonperturbative approach is used to describe the electron-photon interaction by including the radiation field in an exact way via a laser-dressed interaction potential. Through a variational approach we evaluate the donor binding energy. We find that the interaction strength of the laser-dressed Coulomb potential in the z direction cannot only be enhanced but also weakened by the radiation field, while that in the x-y plane is only weakened. In this way, the binding energy of the states with odd z parity, like 2p(z) can be decreased or increased with respect to its static binding energy by the radiation field, while that of the other states can be only decreased. Furthermore, all binding energies become insensitive to the magnetic field if the radiation field is strong. The magnetopolaron effect on these energies is studied within second-order time-dependent perturbation theory. In the nonresonant region, a laser-modulated magnetopolaron correction, including the effect of single-photon processes, is observed. In the resonant region, a laser-modulated magnetopolaron effect, accompanied by the emission and absorption of a single photon, is found. Moreover, the 1s -> 2p(+) transition, accompanied by the emission of a single photon, is tuned by the radiation field into resonance with the longitudinal-optical phonon branch. This is electrically analogous to the magnetopolaron effect, and therefore we name it the dynamical magnetopolaron effect. Finally, by changing the frequency of the radiation field, these interesting effects can be tuned to be far away from the reststrahlen band and, therefore, can be detected experimentally. This in turn provides a direct measure of the electron-phonon interaction.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000457057500001 Publication Date 2019-01-29
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 6 Open Access
Notes ; This work was supported by National Natural Science Foundation of China (Grants No. 11404214, No. 11455015, and No. 61504016) and the China Scholarship Council (CSC), and Science and Technology Research Foundation of Jiangxi Provincial Education Department (Grants No. GJJ161062 and No. GJJ180868). B.V.D. was supported by the Research Foundation – Flanders (FWO-Vl) through a postdoctoral fellowship. ; Approved Most recent IF: 3.836
Call Number UA @ admin @ c:irua:157555 Serial 5218
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Author Hassani, H.; Partoens, B.; Bousquet, E.; Ghosez, P.
Title First-principles study of lattice dynamical properties of the room-temperature P2₁/n and ground-state P2₁/c phases of WO₃ Type A1 Journal article
Year 2022 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 105 Issue 1 Pages (down) 014107
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using first-principles density functional theory, we investigate the dynamical properties of the roomtemperature P21/n and ground-state P21/c phases of WO3. As a preliminary step, we assess the validity of various standard and hybrid functionals, concluding that the best description is achieved with the B1-WC hybrid functional while a reliable description can also be provided using the standard LDA functional. We also carefully rediscuss the structure and energetics of all experimentally observed and a few hypothetical metastable phases in order to provide deeper insight into the unusual sequence of phase transition of WO3 with temperature. Then, we provide a comprehensive theoretical study of the lattice dynamical properties of the P21/n and P21/c phases, reporting zone-center phonons, infrared and Raman spectra, as well as the full phonon dispersion curves, which attest to the dynamical stability of both phases. We carefully discuss the spectra, explaining the physical origin of their main features and evolution from one phase to another. We reveal a systematic connection between the dynamical and structural properties of WO3, highlighting that the number of peaks in the high-frequency range of the Raman spectrum appears as a fingerprint of the number of antipolar distortions that are present in the structure and a practical way to discriminate between the different phases.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000747398100004 Publication Date 2022-01-24
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 5 Open Access Not_Open_Access
Notes Approved Most recent IF: 3.7
Call Number UA @ admin @ c:irua:186388 Serial 6994
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Author Ceyhan, E.; Yagmurcukardes, M.; Peeters, F.M.; Sahin, H.
Title Electronic and magnetic properties of single-layer FeCl₂ with defects Type A1 Journal article
Year 2021 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 103 Issue 1 Pages (down) 014106
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The formation of lattice defects and their effect on the electronic properties of single-layer FeCl2 are investigated by means of first-principles calculations. Among the vacancy defects, namely mono-, di-, and three-Cl vacancies and mono-Fe vacancy, the formation of mono-Cl vacancy is the most preferable. Comparison of two different antisite defects reveals that the formation of the Fe-antisite defect is energetically preferable to the Cl-antisite defect. While a single Cl vacancy leads to a 1 mu(B) decrease in the total magnetic moment of the host lattice, each Fe vacant site reduces the magnetic moment by 4 mu(B). However, adsorption of an excess Cl atom on the surface changes the electronic structure to a ferromagnetic metal or to a ferromagnetic semiconductor depending on the adsorption site without changing the ferromagnetic state of the host lattice. Both Cl-antisite and Fe-antisite defected domains change the magnetic moment of the host lattice by -1 mu(B) and +3 mu(B), respectively. The electronic ground state of defected structures reveals that (i) single-layer FeCl2 exhibits half-metallicity under the formation of vacancy and Cl-antisite defects; (ii) ferromagnetic metallicity is obtained when a single Cl atom is adsorbed on upper-Cl and Fe sites, respectively; and (iii) ferromagnetic semiconducting behavior is found when a Cl atom is adsorbed on a lower-Cl site or a Fe-antisite defect is formed. Simulated scanning electron microscope images show that atomic-scale identification of defect types is possible from their electronic charge density. Further investigation of the periodically Fe-defected structures reveals that the formation of the single-layer FeCl3 phase, which is a dynamically stable antiferromagnetic semiconductor, is possible. Our comprehensive analysis on defects in single-layer FeCl2 will complement forthcoming experimental observations.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000606969400002 Publication Date 2021-01-13
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 5 Open Access Not_Open_Access
Notes ; Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and by Flemish Supercomputer Center (VSC). H.S. acknowledges financial support from the Scientific and Technological Research Council of Turkey (TUBITAK) under Project No. 117F095. M.Y. was supported by the Flemish Science Foundation (FWO-Vl) by a postdoctoral fellowship. ; Approved Most recent IF: 3.836
Call Number UA @ admin @ c:irua:176039 Serial 6689
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