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Author Nguyen, H.T.T.; Obeid, M.M.; Bafekry, A.; Idrees, M.; Vu, T.V.; Phuc, H., V; Hieu, N.N.; Le Hoa, T.; Amin, B.; Nguyen, C., V
Title Interfacial characteristics, Schottky contact, and optical performance of a graphene/Ga2SSe van der Waals heterostructure: Strain engineering and electric field tunability Type A1 Journal article
Year 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 102 Issue 7 Pages 075414-10
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Two-dimensional graphene-based van der Waals heterostructures have received considerable interest because of their intriguing characteristics compared with the constituent single-layer two-dimensional materials. Here, we investigate the interfacial characteristics, Schottky contact, and optical performance of graphene/Ga2SSe van der Waals (vdW) heterostructure using first-principles calculations. The effects of stacking patterns, electric gating, and interlayer coupling on the interfacial properties of graphene/Ga2SSe heterostructures are also examined. Our results demonstrate that the Dirac cone of graphene is well preserved at the F point in all stacking patterns due to the weak vdW interactions, which keep the heterostructures feasible such that they can be obtained in further experiments. Moreover, depending on the stacking patterns, a small band gap of about 13-17 meV opens in graphene and has a high carrier mobility, indicating that the graphene/Ga2SSe heterostructures are potential candidates for future high-speed nanoelectronic applications. In the ground state, the graphene/Ga2SSe heterostructures form an n-type Schottky contact. The transformation from an n-type to a p-type Schottky contact or to an Ohmic contact can be forced by electric gating or by varying the interlayer coupling. Our findings could provide physical guidance for designing controllable Schottky nanodevices with high electronic and optical performances.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000557294500006 Publication Date 2020-08-07
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 3.7 Times cited 12 Open Access
Notes ; This research is funded by Vietnam National Foundation for Science and Technology Development (NAFOSTED) under Grant No. 103.01-2019.05. The authors declare that there are no conflicts of interest regarding the publication of this paper. ; Approved Most recent IF: 3.7; 2020 IF: 3.836
Call Number UA @ admin @ c:irua:171163 Serial 6549
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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 035123
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) 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
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Author Seyedmohammadzadeh, M.; Sevik, C.; Guelseren, O.
Title Two-dimensional heterostructures formed by graphenelike ZnO and MgO monolayers for optoelectronic applications Type A1 Journal article
Year 2022 Publication Physical review materials Abbreviated Journal
Volume 6 Issue 10 Pages 104004-104013
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Two-dimensional heterostructures are an emerging class of materials for novel applications because of extensive engineering potential by tailoring intriguing properties of different layers as well as the ones arising from their interface. A systematic investigation of mechanical, electronic, and optical properties of possible heterostructures formed by bilayer structures graphenelike ZnO and MgO monolayers is presented. Different functionality of each layer makes these heterostructures very appealing for device applications. ZnO layer is convenient for electron transport in these structures, while MgO layer improves electron collection. At the outset, all of the four possible stacking configurations across the heterostructure are mechanically stable. In addition, stability analysis using phonon dispersion reveals that the AB stacking formed by placing the Mg atom on top of the O atom of the ZnO layer is also dynamically stable at zero temperature. Henceforth, we have investigated the optical properties of these stable heterostructures by applying many-body perturbation theory within the framework of GW approximation and solving the Bethe-Salpeter equation. It is demonstrated that strong excitonic effects reduce the optical band gap to the visible light spectrum range. These results show that this new two-dimensional form of ZnO/MgO heterostructures open an avenue for novel optoelectronic device applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000877514900005 Publication Date 2022-10-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2475-9953 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.4 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 3.4
Call Number UA @ admin @ c:irua:192167 Serial 7346
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Author Kocabas, T.; Keceli, M.; Vazquez-Mayagoitia, A.; Sevik, C.
Title Gaussian approximation potentials for accurate thermal properties of two-dimensional materials Type A1 Journal article
Year 2023 Publication Nanoscale Abbreviated Journal
Volume 15 Issue 19 Pages 8772-8780
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract (up) Two-dimensional materials (2DMs) continue to attract a lot of attention, particularly for their extreme flexibility and superior thermal properties. Molecular dynamics simulations are among the most powerful methods for computing these properties, but their reliability depends on the accuracy of interatomic interactions. While first principles approaches provide the most accurate description of interatomic forces, they are computationally expensive. In contrast, classical force fields are computationally efficient, but have limited accuracy in interatomic force description. Machine learning interatomic potentials, such as Gaussian Approximation Potentials, trained on density functional theory (DFT) calculations offer a compromise by providing both accurate estimation and computational efficiency. In this work, we present a systematic procedure to develop Gaussian approximation potentials for selected 2DMs, graphene, buckled silicene, and h-XN (X = B, Al, and Ga, as binary compounds) structures. We validate our approach through calculations that require various levels of accuracy in interatomic interactions. The calculated phonon dispersion curves and lattice thermal conductivity, obtained through harmonic and anharmonic force constants (including fourth order) are in excellent agreement with DFT results. HIPHIVE calculations, in which the generated GAP potentials were used to compute higher-order force constants instead of DFT, demonstrated the first-principles level accuracy of the potentials for interatomic force description. Molecular dynamics simulations based on phonon density of states calculations, which agree closely with DFT-based calculations, also show the success of the generated potentials in high-temperature simulations.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000976615200001 Publication Date 2023-04-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364; 2040-3372 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.7 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 6.7; 2023 IF: 7.367
Call Number UA @ admin @ c:irua:196722 Serial 8873
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Author Chaney, G.; Cakir, D.; Peeters, F.M.; Ataca, C.
Title Stability of adsorption of Mg and Na on sulfur-functionalized MXenes Type A1 Journal article
Year 2021 Publication Physical Chemistry Chemical Physics Abbreviated Journal Phys Chem Chem Phys
Volume 23 Issue 44 Pages 25424-25433
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Two-dimensional materials composed of transition metal carbides and nitrides (MXenes) are poised to revolutionize energy conversion and storage. In this work, we used density functional theory (DFT) to investigate the adsorption of Mg and Na adatoms on five M2CS2 monolayers (where M = Mo, Nb, Ti, V, and Zr) for battery applications. We assessed the stability of the adatom (i.e. Na and Mg)-monolayer systems by calculating adsorption and formation energies, as well as voltages as a function of surface coverage. For instance, we found that Mo2CS2 cannot support a full layer of Na nor even a single Mg atom. Na and Mg exhibit the strongest binding on Zr2CS2, followed by Ti2CS2, Nb2CS2 and V2CS2. Using the nudged elastic band method (NEB), we computed promising diffusion barriers for both dilute and nearly full ion surface coverage cases. In the dilute ion adsorption case, a single Mg and Na atom on Ti2CS2 experience similar to 0.47 eV and similar to 0.10 eV diffusion barriers between the lowest energy sites, respectively. For a nearly full surface coverage, a Na ion moving on Ti2CS2 experiences a similar to 0.33 eV energy barrier, implying a concentration-dependent diffusion barrier. Our molecular dynamics results indicate that the three (one) layers (layer) of the Mg (Na) ion on both surfaces of Ti2CS2 remain stable at T = 300 K. While, according to voltage calculations, Zr2CS2 can store Na up to three atomic layers, our MD simulations predict that the outermost layers detach from the Zr2CS2 monolayer due to the weak interaction between Na ions and the monolayer. This suggests that MD simulations are essential to confirm the stability of an ion-electrode system – an insight that is mostly absent in previous studies.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000716024400001 Publication Date 2021-10-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1463-9076; 1463-9084 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 3 Open Access Not_Open_Access
Notes Approved Most recent IF: 4.123
Call Number UA @ admin @ c:irua:184075 Serial 7020
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Author Yorulmaz, U.; Demiroglu, I.; Cakir, D.; Gulseren, O.; Sevik, C.
Title A systematicalab-initioreview of promising 2D MXene monolayers towards Li-ion battery applications Type A1 Journal article
Year 2020 Publication JPhys Energy Abbreviated Journal
Volume 2 Issue 3 Pages 032006
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract (up) Two-dimensional materials have been attracting increasing interests because of their outstanding properties for Lithium-ion battery applications. In particular, a material family called MXenes (Mn+1Cn, where n = 1, 2, 3) have been recently attracted immense interest in this respect due to their incomparable fast-charging properties and high capacity promises. In this article, we review the state-of-the-art computational progress on Li-ion battery applications of MXene materials in accordance with our systematical DFT calculations. Structural, mechanical, dynamical, and electrical properties of 20 distinct MXene (M: Sc, Ti, V, Cr, Nb, Mo, Hf, Ta, W, and Zr) have been discussed. The battery performances of these MXene monolayers are further investigated by Li-ion binding energies, open circuit voltage values, and Li migration energy barriers. The experimental and theoretical progress up to date demonstrates particularly the potential of non-terminated or pristine MXene materials in Li ion-storage applications. Stability analyses show most of the pristine MXenes should be achievable, however susceptible to the development progress on the experimental growth procedures. Among pristine MXenes, Ti2C, V2C, Sc2C, and Zr2C compounds excel with their high charge/discharge rate prospect due to their extremely low Li diffusion energy barriers. Considering also their higher predicted gravimetric capacities, Sc, Ti, V, and Zr containing MXenes are more promising for their utilization in energy storage applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000569868600001 Publication Date 2020-07-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2515-7655 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.9 Times cited Open Access
Notes Approved Most recent IF: 6.9; 2020 IF: NA
Call Number UA @ admin @ c:irua:193748 Serial 7399
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Author Bafekry, A.; Shayesteh, S.F.; Peeters, F.M.
Title C3N Monolayer: Exploring the Emerging of Novel Electronic and Magnetic Properties with Adatom Adsorption, Functionalizations, Electric Field, Charging, and Strain Type A1 Journal article
Year 2019 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 123 Issue 19 Pages 12485-12499
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract (up) Two-dimensional polyaniline with structural unit C3N is an indirect semiconductor with 0.4 eV band gap, which has attracted a lot of interest because of its unusual electronic, optoelectronic, thermal, and mechanical properties useful for various applications. Adsorption of adatoms is an effective method to improve and tune the properties of C3N. Using first-principles calculations, we investigated the adsorption of adatoms, including H, O, S, F, Cl, B, C, Si, N, P, Al, Li, Na, K, Be, Mg, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn, on C3N. Depending on the adatom size and the number of valence electrons, they may induce metallic, half-metallic, semiconducting, and ferromagnetic-metallic behavior. In addition, we investigate the effects of an electrical field, charging, and strain on C3N and found how the electronic and magnetic properties are modified. Semi- and full hydrogenation are studied. From the mechanical and thermal stability of C3N monolayer, we found it to be a hard material that can withstand large strain. From our calculations, we gained novel insights into the properties of C3N demonstrating its unique electronic and magnetic properties that can be useful for semiconducting, nanosensor, and catalytic applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000468368800053 Publication Date 2019-04-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447; 1932-7455 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 67 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FW0-V1). The authors thank Keyvan Nazifi from the Cluster Center of Faculty of Science, Guilan University, for his help. They acknowledge OpenMX team for OpenMX code. ; Approved Most recent IF: 4.536
Call Number UA @ admin @ c:irua:160323 Serial 5196
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Author de Araujo, J.L.B.; Munarin, F.F.; Farias, G.A.; Peeters, F.M.; Ferreira, W.P.
Title Structure and reentrant percolation in an inverse patchy colloidal system Type A1 Journal article
Year 2017 Publication Physical Review E Abbreviated Journal
Volume 95 Issue 6 Pages 062606
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Two-dimensional systems of inverse patchy colloids modeled as disks with a central charge and having their surface decorated with oppositely pointlike charged patches are investigated using molecular dynamics simulations. The self-assembly of the patchy colloids leads to diverse ground state configurations ranging from crystalline arrangements of monomers to linear clusters, ramified linear clusters and to percolated configurations. Two structural phase diagrams are constructed: (1) as a function of the net charge and area fraction, and (2) as a function of the net charge and the range of the pair interaction potential. An interesting reentrant percolation transition is obtained as a function of the net charge of the colloids. We identify distinct mechanisms that lead to the percolation transition.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000404545700005 Publication Date 2017-06-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 5 Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:152628 Serial 8587
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Author Bekaert, J.; Sevik, C.; Milošević, M.V.
Title Enhancing superconductivity in MXenes through hydrogenation Type A1 Journal article
Year 2022 Publication Nanoscale Abbreviated Journal Nanoscale
Volume 14 Issue 27 Pages 9918-9924
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract (up) Two-dimensional transition metal carbides and nitrides (MXenes) are an emerging class of atomically-thin superconductors, whose characteristics are highly prone to tailoring by surface functionalization. Here we explore the use of hydrogen adatoms to enhance phonon-mediated superconductivity in MXenes, based on first-principles calculations combined with Eliashberg theory. We first demonstrate the stability of three different structural models of hydrogenated Mo- and W-based MXenes. Particularly high critical temperatures of over 30 K are obtained for hydrogenated Mo2N and W2N. Several mechanisms responsible for the enhanced electron-phonon coupling are uncovered, namely (i) hydrogen-induced changes in the phonon spectrum of the host MXene, (ii) emerging hydrogen-based phonon modes, and (iii) charge transfer from hydrogen to the MXene layer, boosting the density of states at the Fermi level. Finally, we demonstrate that hydrogen adatoms are moreover able to induce superconductivity in MXenes that are not superconducting in pristine form, such as Nb2C.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000820350600001 Publication Date 2022-06-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364; 2040-3372 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.7 Times cited 2 Open Access OpenAccess
Notes Approved Most recent IF: 6.7
Call Number UA @ admin @ c:irua:189580 Serial 7155
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Author Demirkol, Ö.; Sevik, C.; Demiroğlu, I.
Title First principles assessment of the phase stability and transition mechanisms of designated crystal structures of pristine and Janus transition metal dichalcogenides Type A1 Journal article
Year 2022 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 24 Issue 12 Pages 7430-7441
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Two-dimensional Transition Metal Dichalcogenides (TMDs) possessing extraordinary physical properties at reduced dimensionality have attracted interest due to their promise in electronic and optical device applications. However, TMD monolayers can show a broad range of different properties depending on their crystal phase; for example, H phases are usually semiconductors, while the T phases are metallic. Thus, controlling phase transitions has become critical for device applications. In this study, the energetically low-lying crystal structures of pristine and Janus TMDs are investigated by using ab initio Nudged Elastic Band and molecular dynamics simulations to provide a general explanation for their phase stability and transition properties. Across all materials investigated, the T phase is found to be the least stable and the H phase is the most stable except for WTe2, while the T' and T '' phases change places according to the TMD material. The transition energy barriers are found to be large enough to hint that even the higher energy phases are unlikely to undergo a phase transition to a more stable phase if they can be achieved except for the least stable T phase, which has zero barrier towards the T ' phase. Indeed, in molecular dynamics simulations the thermodynamically least stable T phase transformed into the T ' phase spontaneously while in general no other phase transition was observed up to 2100 K for the other three phases. Thus, the examined T ', T '' and H phases were shown to be mostly stable and do not readily transform into another phase. Furthermore, so-called mixed phase calculations considered in our study explain the experimentally observed lateral hybrid structures and point out that the coexistence of different phases is strongly stable against phase transitions. Indeed, stable complex structures such as metal-semiconductor-metal architectures, which have immense potential to be used in future device applications, are also possible based on our investigation.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000766791000001 Publication Date 2022-02-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1463-9076; 1463-9084 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.3 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 3.3
Call Number UA @ admin @ c:irua:187184 Serial 7164
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Author Li, L.; Kong, X.; Chen, X.; Li, J.; Sanyal, B.; Peeters, F.M.
Title Monolayer 1T-LaN₂ : Dirac spin-gapless semiconductor of p-state and Chern insulator with a high Chern number Type A1 Journal article
Year 2020 Publication Applied Physics Letters Abbreviated Journal Appl Phys Lett
Volume 117 Issue 14 Pages 143101
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Two-dimensional transition-metal dinitrides have attracted considerable attention in recent years due to their rich magnetic properties. Here, we focus on rare-earth-metal elements and propose a monolayer of lanthanum dinitride with a 1T structural phase, 1T-LaN2. Using first-principles calculations, we systematically investigated the structure, stability, magnetism, and band structure of this material. It is a flexible and stable monolayer exhibiting a low lattice thermal conductivity, which is promising for future thermoelectric devices. The monolayer shows the ferromagnetic ground state with a spin-polarized band structure. Two linear spin-polarized bands cross at the Fermi level forming a Dirac point, which is formed by the p atomic orbitals of the N atoms, indicating that monolayer 1T-LaN2 is a Dirac spin-gapless semiconductor of p-state. When the spin-orbit coupling is taken into account, a large nontrivial indirect bandgap (86/354meV) can be opened at the Dirac point, and three chiral edge states are obtained, corresponding to a high Chern number of C=3, implying that monolayer 1T-LaN2 is a Chern insulator. Importantly, this kind of band structure is expected to occur in more monolayers of rare-earth-metal dinitride with a 1T structural phase.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000578551800001 Publication Date 2020-10-06
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 13 Open Access
Notes ; This work was supported by the Natural Science Foundation of Hebei Province (Grant No. A2020202031), the FLAG-ERA project TRANS2DTMD, the Swedish Research Council project grant (No. 2016-05366), and the Swedish Research Links program grant (No. 2017-05447). The 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, and Swedish National Infrastructure for Computing (SNIC). A portion of this research (Xiangru Kong) was conducted at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility. Xin Chen thanks the China scholarship council for financial support from the China Scholarship Council (CSC, No. 201606220031). ; Approved Most recent IF: 4; 2020 IF: 3.411
Call Number UA @ admin @ c:irua:172674 Serial 6564
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Author Sahin, H.; Tongay, S.; Horzum, S.; Fan, W.; Zhou, J.; Li, J.; Wu, J.; Peeters, F.M.
Title Anomalous Raman spectra and thickness-dependent electronic properties of WSe2 Type A1 Journal article
Year 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 87 Issue 16 Pages 165409-6
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Typical Raman spectra of transition-metal dichalcogenides (TMDs) display two prominent peaks, E-2g and A(1g), that are well separated from each other. We find that these modes are degenerate in bulk WSe2 yielding one single Raman peak in contrast to other TMDs. As the dimensionality is lowered, the observed peak splits in two. In contrast, our ab initio calculations predict that the degeneracy is retained even for WSe2 monolayers. Interestingly, for minuscule biaxial strain, the degeneracy is preserved, but once the crystal symmetry is broken by a small uniaxial strain, the degeneracy is lifted. Our calculated phonon dispersion for uniaxially strained WSe2 shows a good match to the measured Raman spectrum, which suggests that uniaxial strain exists in WSe2 flakes, possibly induced during the sample preparation and/or as a result of the interaction between WSe2 and the substrate. Furthermore, we find that WSe2 undergoes an indirect-to-direct band-gap transition from bulk to monolayers, which is ubiquitous for semiconducting TMDs. These results not only allow us to understand the vibrational and electronic properties of WSe2, but also point to effects of the interaction between the monolayer TMDs and the substrate on the vibrational and electronic properties. DOI: 10.1103/PhysRevB.87.165409
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000317195400007 Publication Date 2013-04-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 365 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem programme of the Flemish government. Computational resources were partially provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H. S. is supported by the FWO Pegasus Marie Curie Long Fellowship program. ; Approved Most recent IF: 3.836; 2013 IF: 3.664
Call Number UA @ lucian @ c:irua:108471 Serial 134
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Author Zeng, Y.-J.; Schouteden, K.; Amini, M.N.; Ruan, S.-C.; Lu, Y.-F.; Ye, Z.-Z.; Partoens, B.; Lamoen, D.; Van Haesendonck, C.
Title Electronic band structures and native point defects of ultrafine ZnO nanocrystals Type A1 Journal article
Year 2015 Publication ACS applied materials and interfaces Abbreviated Journal Acs Appl Mater Inter
Volume 7 Issue 7 Pages 10617-10622
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract (up) Ultrafine ZnO nanocrystals with a thickness down to 0.25 nm are grown by a metalorganic chemical vapor deposition method. Electronic band structures and native point defects of ZnO nanocrystals are studied by a combination of scanning tunneling microscopy/spectroscopy and first-principles density functional theory calculations. Below a critical thickness of nm ZnO adopts a graphitic-like structure and exhibits a wide band gap similar to its wurtzite counterpart. The hexagonal wurtzite structure, with a well-developed band gap evident from scanning tunneling spectroscopy, is established for a thickness starting from similar to 1.4 nm. With further increase of the thickness to 2 nm, V-O-V-Zn defect pairs are easily produced in ZnO nanocrystals due to the self-compensation effect in highly doped semiconductors.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000355055000063 Publication Date 2015-04-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1944-8244;1944-8252; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.504 Times cited 15 Open Access
Notes Hercules; EWI Approved Most recent IF: 7.504; 2015 IF: 6.723
Call Number c:irua:126408 Serial 999
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Author Guidini, A.; Flammia, L.; Milošević, M.V.; Perali, A.
Title BCS-BEC crossover in quantum confined superconductors Type A1 Journal article
Year 2016 Publication Journal of superconductivity and novel magnetism Abbreviated Journal J Supercond Nov Magn
Volume 29 Issue 29 Pages 711-715
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Ultranarrow superconductors are in the strong quantum confinement regime with formation of multiple coherent condensates associated with the many subbands of the electronic structure. Here, we analyze the multiband BCS-BEC crossover induced by the chemical potential tuned close to a subband bottom, in correspondence of a superconducting shape resonance. The evolution of the condensate fraction and of the pair correlation length in the ground state as functions of the chemical potential demonstrates the tunability of the BCS-BEC crossover for the condensate component of the selected subband. The extension of the crossover regime increases when the pairing strength and/or the characteristic energy of the interaction get larger. Our results indicate the coexistence of large and small Cooper pairs in the crossover regime, leading to the optimal parameter configuration for high transition temperature superconductivity.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000371089500034 Publication Date 2015-12-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1557-1939 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.18 Times cited 12 Open Access
Notes ; We acknowledge A. Bianconi and A.A. Shanenko for useful discussions. A.P. acknowledges financial support from the University of Camerino under the project FAR “Control and enhancement of superconductivity by engineering materials at the nanoscale”. M.V.M. acknowledges support from the Research Foundation – Flanders (FWO) and the Special Research Funds of the University of Antwerp (BOF-UA). A.P. and M.V.M. acknowledge the collaboration within the MultiSuper International Network (http://www.multisuper.org) for exchange of ideas and suggestions. ; Approved Most recent IF: 1.18
Call Number UA @ lucian @ c:irua:132287 Serial 4143
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Author Cariglia, M.; Vargas-Paredes, A.; Doria, M.M.; Bianconi, A.; Milošević, M.V.; Perali, A.
Title Shape-Resonant Superconductivity in Nanofilms: from Weak to Strong Coupling Type A1 Journal article
Year 2016 Publication Journal of superconductivity and novel magnetism Abbreviated Journal J Supercond Nov Magn
Volume 29 Issue 29 Pages 3081-3086
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Ultrathin superconductors of different materials are becoming a powerful platform to find mechanisms for enhancement of superconductivity, exploiting shape resonances in different superconducting properties. Here, we evaluate the superconducting gap and its spatial profile, the multiple gap components, and the chemical potential, of generic superconducting nanofilms, considering the pairing attraction and its energy scale as tunable parameters, from weak to strong coupling, at fixed electron density. Superconducting properties are evaluated at mean field level as a function of the thickness of the nanofilm, in order to characterize the shape resonances in the superconducting gap. We find that the most pronounced shape resonances are generated for weakly coupled superconductors, while approaching the strong coupling regime the shape resonances are rounded by a mixing of the subbands due to the large energy gaps extending over large energy scales. Finally, we find that the spatial profile, transverse to the nanofilm, of the superconducting gap acquires a flat behavior in the shape resonance region, indicating that a robust and uniform multigap superconducting state can arise at resonance.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000390030600016 Publication Date 2016-08-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1557-1939 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.18 Times cited 11 Open Access
Notes ; We acknowledge D. Valentinis, D. Van der Marel, and C. Berthod for useful discussions. A. Ricci is also acknowledged for his comments on the experimental detection of the predictions of this paper. A. Bianconi acknowledges financial support from Superstripes non-profit organization. M. Cariglia acknowledges CNPq support from project (205029 / 2014-0) and FAPEMIG support from project APQ-02164-14. M.M. Doria acknowledges CNPq support from funding (23079.014992 / 2015-39). M.V. Milosevic acknowledges support from Research Foundation – Flanders (FWO). A. Perali acknowledges financial support from the University of Camerino under the project FAR “Control and enhancement of superconductivity by engineering materials at the nanoscale”. All authors acknowledge the collaboration within the MultiSuper Network (http://www.multisuper.org) for exchange of ideas and suggestions. ; Approved Most recent IF: 1.18
Call Number UA @ lucian @ c:irua:140347 Serial 4461
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Author Kahraman, Z.; Kandemir, A.; Yagmurcukardes, M.; Sahin, H.
Title Single-layer Janus-type platinum dichalcogenides and their heterostructures Type A1 Journal article
Year 2019 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 123 Issue 7 Pages 4549-4557
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract (up) Ultrathin two-dimensional Janus-type platinum dichalcogenide crystals formed by two different atoms at opposite surfaces are investigated by performing state-of-the-art density functional theory calculations. First, it is shown that single-layer PtX2 structures (where X = S, Se, or Te) crystallize into the dynamically stable IT phase and are indirect band gap semiconductors. It is also found that the substitutional chalcogen doping in all PtX2 structures is favorable via replacement of surface atoms with a smaller chalcogen atom, and such a process leads to the formation of Janus-type platinum dichalcogenides (XPtY, where X and Y stand for S, Se, or Te) which are novel single-layer crystals. While all Janus structures are indirect band gap semiconductors as their binary analogues, their Raman spectra show distinctive features that stem from the broken out-of-plane symmetry. In addition, it is revealed that the construction of Janus crystals enhances the piezoelectric constants of PtX2 crystals significantly both in the in plane and in the out-of-plane directions. Moreover, it is shown that vertically stacked van der Waals heterostructures of binary and ternary (Janus) platinum dichalcogenides offer a wide range of electronic features by forming bilayer heterojunctions of type-I, type-II, and type-III, respectively. Our findings reveal that Janus-type ultrathin platinum dichalcogenide crystals are quite promising materials for optoelectronic device applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000459836900071 Publication Date 2019-01-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447; 1932-7455 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 20 Open Access
Notes ; Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H.S. and Z.K. acknowledge financial support from the TUBITAK under the project number 117F095. This work is supported by the Flemish Science Foundation (FWO-Vl) by a post-doctoral fellowship (M.Y.). H.S. acknowledges support from Turkiye Bilimler Akademisi-Turkish Academy of Sciences under the GEBIP program. ; Approved Most recent IF: 4.536
Call Number UA @ admin @ c:irua:158617 Serial 5229
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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 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 (up) 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.
Address
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 Neek-Amal, M.; Rashidi, R.; Nair, R.R.; Neilson, D.; Peeters, F.M.
Title Electric-field-induced emergent electrical connectivity in graphene oxide Type A1 Journal article
Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 99 Issue 11 Pages 115425
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Understanding the appearance of local electrical connectivity in liquid filled layered graphene oxide subjected to an external electric field is important to design electrically controlled smart permeable devices and also to gain insight into the physics behind electrical effects on confined water permeation. Motivated by recent experiments [K. G. Zhou et al. Nature (London) 559, 236 (2018)], we introduce a new model with random percolating paths for electrical connectivity in micron thick water filled layered graphene oxide, which mimics parallel resistors connected across the top and bottom electrodes. We find that a strong nonuniform radial electric field of the order similar to 10-50 mV/nm can be induced between layers depending on the current flow through the formed conducting paths. The maxima of the induced fields are not necessarily close to the electrodes and may be localized in the middle region of the layered material. The emergence of electrical connectivity and the associated electrical effects have a strong influence on the surrounding fluid in terms of ionization and wetting which subsequently determines the permeation properties.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000461960100001 Publication Date 2019-03-19
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 3 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem program. ; Approved Most recent IF: 3.836
Call Number UA @ admin @ c:irua:158534 Serial 5206
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Author McNaughton, B.; Pinto, N.; Perali, A.; Milošević, M.V.
Title Causes and consequences of ordering and dynamic phases of confined vortex rows in superconducting nanostripes Type A1 Journal article
Year 2022 Publication Nanomaterials Abbreviated Journal Nanomaterials-Basel
Volume 12 Issue 22 Pages 4043-18
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract (up) Understanding the behaviour of vortices under nanoscale confinement in superconducting circuits is important for the development of superconducting electronics and quantum technologies. Using numerical simulations based on the Ginzburg-Landau theory for non-homogeneous superconductivity in the presence of magnetic fields, we detail how lateral confinement organises vortices in a long superconducting nanostripe, presenting a phase diagram of vortex configurations as a function of the stripe width and magnetic field. We discuss why the average vortex density is reduced and reveal that confinement influences vortex dynamics in the dissipative regime under sourced electrical current, mapping out transitions between asynchronous and synchronous vortex rows crossing the nanostripe as the current is varied. Synchronous crossings are of particular interest, since they cause single-mode modulations in the voltage drop along the stripe in a high (typically GHz to THz) frequency range.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000887683200001 Publication Date 2022-11-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2079-4991 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.3 Times cited 2 Open Access OpenAccess
Notes Approved Most recent IF: 5.3
Call Number UA @ admin @ c:irua:192731 Serial 7286
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Author Pandey, T.; Peeters, F.M.; Milošević, M.V.
Title Pivotal role of magnetic ordering and strain in lattice thermal conductivity of chromium-trihalide monolayers Type A1 Journal article
Year 2022 Publication 2D materials Abbreviated Journal 2D Mater
Volume 9 Issue 1 Pages 015034
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Understanding the coupling between spin and phonons is critical for controlling the lattice thermal conductivity (kappa ( l )) in magnetic materials, as we demonstrate here for CrX3 (X = Br and I) monolayers. We show that these compounds exhibit large spin-phonon coupling (SPC), dominated by out-of-plane vibrations of Cr atoms, resulting in significantly different phonon dispersions in ferromagnetic (FM) and paramagnetic (PM) phases. Lattice thermal conductivity calculations provide additional evidence for strong SPC, where particularly large kappa ( l ) is found for the FM phase. Most strikingly, PM and FM phases exhibit radically different behavior with tensile strain, where kappa ( l ) increases with strain for the PM phase, and strongly decreases for the FM phase-as we explain through analysis of phonon lifetimes and scattering rates. Taken all together, we uncover the high significance of SPC on the phonon transport in CrX3 monolayers, a result extendable to other 2D magnetic materials, that will be useful in further design of thermal spin devices.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000735170300001 Publication Date 2021-12-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2053-1583 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.5 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 5.5
Call Number UA @ admin @ c:irua:184642 Serial 7010
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Author Zarenia, M.; Leenaerts, O.; Partoens, B.; Peeters, F.M.
Title Substrate-induced chiral states in graphene Type A1 Journal article
Year 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 86 Issue 8 Pages 085451
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Unidirectional chiral states are predicted in single layer graphene which originate from the breaking of the sublattice symmetry due to an asymmetric mass potential. The latter can be created experimentally using boron-nitride (BN) substrates with a line defect (B-B or N-N) that changes the induced mass potential in graphene. Solving the Dirac-Weyl equation, the obtained energy spectrum is compared with the one calculated using ab initio density functional calculations. We found that these one-dimensional chiral states are very robust and they can even exist in the presence of a small gap between the mass regions. In the latter case additional bound states are found that are topologically different from those chiral states.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000308005600015 Publication Date 2012-08-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 41 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl), and the European Science Foundation (ESF) under the EUROCORES Program: EuroGRAPHENE (project CONGRAN). ; Approved Most recent IF: 3.836; 2012 IF: 3.767
Call Number UA @ lucian @ c:irua:101100 Serial 3347
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Author Milošević, M.V.; Peeters, F.M.; Jankó, B.
Title Vortex manipulation in superconducting films with tunable magnetic topology Type A1 Journal article
Year 2011 Publication Superconductor science and technology Abbreviated Journal Supercond Sci Tech
Volume 24 Issue 2 Pages 024001-024001,6
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Using a combination of the phenomenological GinzburgLandau theory and micromagnetic simulations, we study properties of a superconducting film with an array of soft magnetic dots on top. An external in-plane magnetic field gradually drives the magnets from an out-of-plane or magnetic vortex state to an in-plane single-domain state, which changes spatially the distribution of the superconducting condensate. If induced by the magnets, the vortexantivortex molecules exhibit rich transitions as a function of the applied in-plane field. At the same time, we show how the magnetic dots act as very effective dynamic pinning centers for vortices in an applied perpendicular magnetic field.
Address
Corporate Author Thesis
Publisher Place of Publication Bristol Editor
Language Wos 000286379900002 Publication Date 2011-01-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-2048;1361-6668; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.878 Times cited 8 Open Access
Notes ; This research was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), the JSPS/ESF-NES program, the bilateral project between Flanders and the USA, NSF NIRT, ECS-0609249, and the Institute for Theoretical Sciences. ; Approved Most recent IF: 2.878; 2011 IF: 2.662
Call Number UA @ lucian @ c:irua:88731 Serial 3870
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Author Muñoz, W.A.; Covaci, L.; Peeters, F.M.
Title Superconducting current and proximity effect in ABA and ABC multilayer graphene Josephson junctions Type A1 Journal article
Year 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 88 Issue 88 Pages 214502
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Using a numerical tight-binding approach based on the Chebyshev–Bogoliubov–de Gennes method we describe Josephson junctions made of multilayer graphene contacted by top superconducting gates. Both Bernal (ABA) and rhombohedral (ABC) stacking are considered and we find that the type of stacking has a strong effect on the proximity effect and the supercurrent flow. For both cases the pair amplitude shows a polarization between dimer and nondimer atoms, being more pronounced for rhombohedral stacking. Even though the proximity effect in nondimer sites is enhanced when compared to single-layer graphene, we find that the supercurrent is suppressed. The spatial distribution of the supercurrent shows that for Bernal stacking the current flows only in the topmost layers while for rhombohedral stacking the current flows throughout the whole structure.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000328569900004 Publication Date 2013-12-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 4 Open Access
Notes This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem funding of the Flemish Government Approved Most recent IF: 3.836; 2013 IF: 3.664
Call Number CMT @ cmt @ c:irua:128896 Serial 3962
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Author Souza, J.C.B.; Vizarim, N.P.; Reichhardt, C.J.O.; Reichhardt, C.; Venegas, P.A.
Title Magnus induced diode effect for skyrmions in channels with periodic potentials Type A1 Journal article
Year 2023 Publication Journal of physics : condensed matter Abbreviated Journal
Volume 35 Issue 1 Pages 015804-15810
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Using a particle based model, we investigate the skyrmion dynamical behavior in a channel where the upper wall contains divots of one depth and the lower wall contains divots of a different depth. Under an applied driving force, skyrmions in the channels move with a finite skyrmion Hall angle that deflects them toward the upper wall for -x direction driving and the lower wall for +x direction driving. When the upper divots have zero height, the skyrmions are deflected against the flat upper wall for -x direction driving and the skyrmion velocity depends linearly on the drive. For +x direction driving, the skyrmions are pushed against the lower divots and become trapped, giving reduced velocities and a nonlinear velocity-force response. When there are shallow divots on the upper wall and deep divots on the lower wall, skyrmions get trapped for both driving directions; however, due to the divot depth difference, skyrmions move more easily under -x direction driving, and become strongly trapped for +x direction driving. The preferred -x direction motion produces what we call a Magnus diode effect since it vanishes in the limit of zero Magnus force, unlike the diode effects observed for asymmetric sawtooth potentials. We show that the transport curves can exhibit a series of jumps or dips, negative differential conductivity, and reentrant pinning due to collective trapping events. We also discuss how our results relate to recent continuum modeling on a similar skyrmion diode system.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000880827900001 Publication Date 2022-10-22
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 2.7 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 2.7; 2023 IF: 2.649
Call Number UA @ admin @ c:irua:192031 Serial 7320
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Author Vizarim, N.P.; Souza, J.C.B.; Reichhardt, C.J.O.; Reichhardt, C.; Milošević, M.V.; Venegas, P.A.
Title Soliton motion in skyrmion chains : stabilization and guidance by nanoengineered pinning Type A1 Journal article
Year 2022 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 105 Issue 22 Pages 224409-224412
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Using a particle-based model we examine the depinning motion of solitons in skyrmion chains in quasi -onedimensional (1D) and two-dimensional (2D) systems containing embedded 1D interfaces. The solitons take the form of a particle or hole in a commensurate chain of skyrmions. Under an applied drive, just above a critical depinning threshold, the soliton moves with a skyrmion Hall angle of zero. For higher drives, the entire chain depins, and in a 2D system we observe that both the solitons and chain move at zero skyrmion Hall angle and then transition to a finite skyrmion Hall angle as the drive increases. In a 2D system with a 1D interface that is at an angle to the driving direction, there can be a reversal of the sign of the skyrmion Hall angle from positive to negative. Our results suggest that solitons in skyrmion systems could be used as information carriers in racetrack geometries that would avoid the drawbacks of finite skyrmion Hall angles. The soliton states become mobile at significantly lower drives than the depinning transition of the skyrmion chains themselves.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000823038900004 Publication Date 2022-06-16
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 2 Open Access OpenAccess
Notes Approved Most recent IF: 3.7
Call Number UA @ admin @ c:irua:189671 Serial 7209
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Author Bellizotti Souza, J.C.; Vizarim, N.P.; Reichhardt, C.J.O.; Reichhardt, C.; Venegas, P.A.
Title Clogging, diode and collective effects of skyrmions in funnel geometries Type A1 Journal article
Year 2022 Publication New journal of physics Abbreviated Journal New J Phys
Volume 24 Issue 10 Pages 103030-14
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Using a particle-based model, we examine the collective dynamics of skyrmions interacting with a funnel potential under dc driving as the skyrmion density and relative strength of the Magnus and damping terms are varied. For driving in the easy direction, we find that increasing the skyrmion density reduces the average skyrmion velocity due to jamming of skyrmions near the funnel opening, while the Magnus force causes skyrmions to accumulate on one side of the funnel array. For driving in the hard direction, there is a critical skyrmion density below which the skyrmions become trapped. Above this critical value, a clogging effect appears with multiple depinning and repinning states where the skyrmions can rearrange into different clogged configurations, while at higher drives, the velocity-force curves become continuous. When skyrmions pile up near the funnel opening, the effective size of the opening is reduced and the passage of other skyrmions is blocked by the repulsive skyrmion-skyrmion interactions. We observe a strong diode effect in which the critical depinning force is higher and the velocity response is smaller for hard direction driving. As the ratio of Magnus force to dissipative term is varied, the skyrmion velocity varies in a non-linear and non-monotonic way due to the pile up of skyrmions on one side of the funnels. At high Magnus forces, the clogging effect for hard direction driving is diminished.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000873333400001 Publication Date 2022-10-04
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 3.3 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 3.3
Call Number UA @ admin @ c:irua:192178 Serial 7287
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Author Frota, D.A.; Chaves, A.; Ferreira, W.P.; Farias, G.A.; Milošević, M.V.
Title Superconductor-ferromagnet bilayer under external drive : the role of vortex-antivortex matter Type A1 Journal article
Year 2016 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 119 Issue 119 Pages 093912
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Using advanced Ginzburg-Landau simulations, we study the superconducting state of a thin superconducting film under a ferromagnetic layer, separated by an insulating oxide, in applied external magnetic field and electric current. The taken uniaxial ferromagnet is organized into a series of parallel domains with alternating polarization of out-of-plane magnetization, sufficiently strong to induce vortex-antivortex pairs in the underlying superconductor in absence of other magnetic field. We show the organization of such vortex-antivortex matter into rich configurations, some of which are not matching the periodicity of the ferromagnetic film. The variety of possible configurations is enhanced by applied homogeneous magnetic field, where additional vortices in the superconductor may lower the energy of the system by either annihilating the present antivortices under negative ferromagnetic domains or by lowering their own energy after positioning under positive ferromagnetic domains. As a consequence, both the vortex-antivortex reordering in increasing external field and the evolution of the energy of the system are highly nontrivial. Finally, we reveal the very interesting effects of applied dc electric current on the vortex-antivortex configurations, since resulting Lorentzian force has opposite direction for vortices and antivortices, while direction of the applied current with respect to ferromagnetic domains is of crucial importance for the interaction of the applied and the Meissner current, as well as the consequent vortex-antivortex dynamics-both of which are reflected in the anisotropic critical current of the system. (C) 2016 AIP Publishing LLC.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000372351900018 Publication Date 2016-03-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979; 1089-7550 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.068 Times cited 4 Open Access
Notes ; This work was supported by the Brazilian agencies CNPq, PRONEX/FUNCAP, and CAPES, and the Research Foundation-Flanders (FWO). ; Approved Most recent IF: 2.068
Call Number UA @ lucian @ c:irua:133200 Serial 4255
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Author Berdiyorov, G.R.; Milošević, M.V.; Savel'ev, S.; Kusmartsev, F.; Peeters, F.M.
Title Parametric amplification of vortex-antivortex pair generation in a Josephson junction Type A1 Journal article
Year 2014 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 90 Issue 13 Pages 134505
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Using advanced three-dimensional simulations, we show that an Abrikosov vortex, trapped inside a cavity perpendicular to an artificial Josephson junction, can serve as a very efficient source for generation of Josephson vortex-antivortex pairs in the presence of the applied electric current. In such a case, the nucleation rate of the pairs can be tuned in a broad range by an out-of-plane ac magnetic field in a broad range of frequencies. This parametrically amplified vortex-antivortex nucleation can be considered as a macroscopic analog of the dynamic Casimir effect, where fluxon pairs mimic the photons and the ac magnetic field plays the role of the oscillating mirrors. The emerging vortex pairs in our system can be detected by the pronounced features in the measured voltage characteristics, or through the emitted electromagnetic radiation, and exhibit resonant dynamics with respect to the frequency of the applied magnetic field. Reported tunability of the Josephson oscillations can be useful for developing high-frequency emission devices.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000344025100003 Publication Date 2014-10-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 22 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-VI) and the Leverhulme Trust. G.R.B. acknowledges support from a EU-Marie Curie individual grant (Grant No. 253057) ; Approved Most recent IF: 3.836; 2014 IF: 3.736
Call Number UA @ lucian @ c:irua:121176 Serial 2553
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Author Govaerts, K.; Sluiter, M.H.F.; Partoens, B.; Lamoen, D.
Title Stability of Sb-Te layered structures : first-principles study Type A1 Journal article
Year 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 85 Issue 14 Pages 144114-144114,8
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract (up) Using an effective one-dimensional cluster expansion in combination with first-principles electronic structure calculations we have studied the energetics and electronic properties of Sb-Te layered systems. For a Te concentration between 0 and 60 at. % an almost continuous series of metastable structures is obtained consisting of consecutive Sb bilayers next to consecutive Sb2Te3 units, with the general formula (Sb-2)(n)(Sb2Te3)(m) (n, m = 1,2, ... ). Between 60 and 100 at.% no stable structures are found. We account explicitly for the weak van derWaals bonding between Sb bilayers and Sb2Te3 units by using a recently developed functional, which strongly improves the interlayer bonding distances. At T = 0 K, no evidence is found for the existence of two separate single-phase regions delta and gamma and a two-phase region delta + gamma. Metastable compounds with a Te concentration between 0 and 40 at. % are semimetallic, whereas compounds with a Te concentration between 50 and 60 at. % are semiconducting. Compounds with an odd number of Sb layers are metallic and have a much higher formation energy than those with an even number of consecutive Sb layers, thereby favoring the formation of Sb bilayers.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000303115400004 Publication Date 2012-04-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 14 Open Access
Notes Iwt; Fwo Approved Most recent IF: 3.836; 2012 IF: 3.767
Call Number UA @ lucian @ c:irua:98255 Serial 3129
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Author Nowak, M.P.; Szafran, B.; Peeters, F.M.; Partoens, B.; Pasek, W.J.
Title Tuning of the spin-orbit interaction in a quantum dot by an in-plane magnetic field Type A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 83 Issue 24 Pages 245324-245324,12
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Using an exact-diagonalization approach we show that one- and two-electron InAs quantum dots exhibit an avoided crossing in the energy spectra that is induced by the spin-orbit coupling in the presence of an in-plane external magnetic field. The width of the avoided crossings depends strongly on the orientation of the magnetic field, which reveals the intrinsic anisotropy of the spin-orbit-coupling interactions. We find that for specific orientations of the magnetic field avoided crossings vanish. A value of this orientation can be used to extract the ratio of the strength of Rashba and Dresselhaus interactions. The spin-orbit anisotropy effects for various geometries and orientations of the confinement potential are discussed. Our analysis explains the physics behind the recent measurements performed on a gated self-assembled quantum dot [ S. Takahashi et al. Phys. Rev. Lett. 104 246801 (2010)].
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000292254000005 Publication Date 2011-06-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 27 Open Access
Notes ; The authors thank S. Takahashi for helpful discussions. This work was supported by the “Krakow Interdisciplinary PhD Project in Nanoscience and Advanced Nanostructures” operated within the Foundation for Polish Science MPD Programme co-financed by the EU European Regional Development Fund, the Project No. N N202103938 supported by the Ministry of Science an Higher Education (MNiSW) for 2010-2013, and the Belgian Science Policy (IAP). W. J. P. has been partially supported by the EU Human Capital Operation Program, Polish Project No. POKL.04.0101-00-434/08-00. Calculations were performed in ACK-CYFRONET-AGH on the RackServer Zeus. ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number UA @ lucian @ c:irua:90923 Serial 3755
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