Records |
Author |
Bafekry, A.; Ghergherehchi, M.; Shayesteh, S.F. |
Title |
Tuning the electronic and magnetic properties of antimonene nanosheets via point defects and external fields: first-principles calculations |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
Volume |
21 |
Issue |
20 |
Pages |
10552-10566 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Defects are inevitably present in materials, and their existence in a material strongly affects its fundamental physical properties. We have systematically investigated the effects of surface adsorption, substitutional impurities, defect engineering, an electric field and strain engineering on the structural, electronic and magnetic properties of antimonene nanosheets, using spin-polarized density functional calculations based on first-principles. The adsorption or substitution of atoms can locally modify the atomic and electronic structures as well as induce a variety of electronic behaviors including metal, half-metal, ferromagnetic metal, dilute magnetic semiconductor and spin-glass semiconductor. Our calculations show that the presence of typical defects (vacancies and Stone-Wales defect) in antimonene affects the geometrical symmetry as well as the band gap in the electronic band structure and induces magnetism to antimonene. Moreover, by applying an external electric field and strain (uniaxial and biaxial), the electronic structure of antimonene can be easily modified. The calculation results presented in this paper provide a fundamental insight into the tunable nature of the electronic properties of antimonene, supporting its promise for use in future applications. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000476561000031 |
Publication Date |
2019-04-25 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1463-9076; 1463-9084 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.123 |
Times cited |
17 |
Open Access |
|
Notes |
; ; |
Approved |
Most recent IF: 4.123 |
Call Number |
UA @ admin @ c:irua:161945 |
Serial |
5430 |
Permanent link to this record |
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Author |
Bafekry, A.; Stampfl, C.; Shayesteh, S.F. |
Title |
A first-principles study of C3N nanostructures : control and engineering of the electronic and magnetic properties of nanosheets, tubes and ribbons |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Chemphyschem |
Abbreviated Journal |
Chemphyschem |
Volume |
21 |
Issue |
2 |
Pages |
164-174 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Using first-principles calculations we systematically investigate the atomic, electronic and magnetic properties of novel two-dimensional materials (2DM) with a stoichiometry C3N which has recently been synthesized. We investigate how the number of layers affect the electronic properties by considering monolayer, bilayer and trilayer structures, with different stacking of the layers. We find that a transition from semiconducting to metallic character occurs which could offer potential applications in future nanoelectronic devices. We also study the affect of width of C3N nanoribbons, as well as the radius and length of C3N nanotubes, on the atomic, electronic and magnetic properties. Our results show that these properties can be modified depending on these dimensions, and depend markedly on the nature of the edge states. Functionalization of the nanostructures by the adsorption of H adatoms is found induce metallic, half-metallic, semiconducting and ferromagnetic behavior, which offers an approach to tailor the properties, as can the application of strain. Our calculations give insight into this new family of C3N nanostructures, which reveal unusual electronic and magnetic properties, and may have great potential in applications such as sensors, electronics and optoelectronic at the nanoscale. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000503453100001 |
Publication Date |
2019-11-09 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1439-4235 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.9 |
Times cited |
27 |
Open Access |
|
Notes |
; ; |
Approved |
Most recent IF: 2.9; 2020 IF: 3.075 |
Call Number |
UA @ admin @ c:irua:165045 |
Serial |
6282 |
Permanent link to this record |
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Author |
Kenawy, A.; Magnus, W.; Milošević, M.V.; Sorée, B. |
Title |
Electronically tunable quantum phase slips in voltage-biased superconducting rings as a base for phase-slip flux qubits |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Superconductor Science & Technology |
Abbreviated Journal |
Supercond Sci Tech |
Volume |
33 |
Issue |
12 |
Pages |
125002 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Quantum phase slips represent a coherent mechanism to couple flux states of a superconducting loop. Since their first direct observation, there have been substantial developments in building charge-insensitive quantum phase-slip circuits. At the heart of these devices is a weak link, often a nanowire, interrupting a superconducting loop. Owing to the very small cross-sectional area of such a nanowire, quantum phase slip rates in the gigahertz range can be achieved. Instead, here we present the use of a bias voltage across a superconducting loop to electrostatically induce a weak link, thereby amplifying the rate of quantum phase slips without physically interrupting the loop. Our simulations reveal that the bias voltage modulates the free energy barrier between subsequent flux states in a very controllable fashion, providing a route towards a phase-slip flux qubit with a broadly tunable transition frequency. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000577207000001 |
Publication Date |
2020-09-16 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0953-2048 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.6 |
Times cited |
4 |
Open Access |
|
Notes |
; ; |
Approved |
Most recent IF: 3.6; 2020 IF: 2.878 |
Call Number |
UA @ admin @ c:irua:172643 |
Serial |
6503 |
Permanent link to this record |
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Author |
Mao, J.; Milovanović, S.P.; Andelkovic, M.; Lai, X.; Cao, Y.; Watanabe, K.; Taniguchi, T.; Covaci, L.; Peeters, F.M.; Geim, A.K.; Jiang, Y.; Andrei, E.Y. |
Title |
Evidence of flat bands and correlated states in buckled graphene superlattices |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Nature |
Abbreviated Journal |
Nature |
Volume |
584 |
Issue |
7820 |
Pages |
215-220 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
Abstract |
Two-dimensional atomic crystals can radically change their properties in response to external influences, such as substrate orientation or strain, forming materials with novel electronic structure(1-5). An example is the creation of weakly dispersive, 'flat' bands in bilayer graphene for certain 'magic' angles of twist between the orientations of the two layers(6). The quenched kinetic energy in these flat bands promotes electron-electron interactions and facilitates the emergence of strongly correlated phases, such as superconductivity and correlated insulators. However, the very accurate fine-tuning required to obtain the magic angle in twisted-bilayer graphene poses challenges to fabrication and scalability. Here we present an alternative route to creating flat bands that does not involve fine-tuning. Using scanning tunnelling microscopy and spectroscopy, together with numerical simulations, we demonstrate that graphene monolayers placed on an atomically flat substrate can be forced to undergo a buckling transition(7-9), resulting in a periodically modulated pseudo-magnetic field(10-14), which in turn creates a 'post-graphene' material with flat electronic bands. When we introduce the Fermi level into these flat bands using electrostatic doping, we observe a pseudogap-like depletion in the density of states, which signals the emergence of a correlated state(15-17). This buckling of two-dimensional crystals offers a strategy for creating other superlattice systems and, in particular, for exploring interaction phenomena characteristic of flat bands. Buckled monolayer graphene superlattices are found to provide an alternative to twisted bilayer graphene for the study of flat bands and correlated states in a carbon-based material. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000559831500012 |
Publication Date |
2020-08-12 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0028-0836 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
64.8 |
Times cited |
109 |
Open Access |
Not_Open_Access |
Notes |
; ; |
Approved |
Most recent IF: 64.8; 2020 IF: 40.137 |
Call Number |
UA @ admin @ c:irua:171150 |
Serial |
6513 |
Permanent link to this record |
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Author |
Bafekry, A. |
Title |
Graphene-like BC₆N single-layer: tunable electronic and magnetic properties via thickness, gating, topological defects, and adatom/molecule |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Physica E-Low-Dimensional Systems & Nanostructures |
Abbreviated Journal |
Physica E |
Volume |
118 |
Issue |
|
Pages |
113850-15 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
By using density functional theory-based first-principles calculations, we investigate the structural, electronic, optical, and transport properties of pristine single-layer BC6N. Under different external actions and functionalization. Increasing the thickness of the structure results in a decrease of the band gap. Applying a perpendicular electric field decreases the band gap and a semiconductor-to-topological insulator transition is revealed. Uniaxial and biaxial strains of +8% result in a semiconductor-to-metal transition. Nanoribbons of BC6N having zigzag edge with even (odd) values of widths, become metal (semiconductor), while the armchair edge nanoribbons exhibit robust semiconducting behavior. In addition, we systematically investigate the effect of surface adatom and molecule, substitutional impurity and defect engineering on the electronic properties of single-layer BC6N and found transitions from metal to half-metal, to ferromagnetic metal, to dilute magnetic semiconductor, and even to spin-glass semiconductor. Furthermore we found that, topological defects including vacancies and Stone–Wales type, induce magnetism in single-layer BC6N. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000515321700032 |
Publication Date |
2019-12-04 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1386-9477 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.3 |
Times cited |
30 |
Open Access |
|
Notes |
; ; |
Approved |
Most recent IF: 3.3; 2020 IF: 2.221 |
Call Number |
UA @ admin @ c:irua:169750 |
Serial |
6530 |
Permanent link to this record |
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Author |
Van der Donck, M.; Zarenia, M.; Peeters, F.M. |
Title |
Reply to “Comment on `Excitons, trions, and biexcitons in transition-metal dichalcogenides: Magnetic-field dependence'” |
Type |
Editorial |
Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
Volume |
101 |
Issue |
12 |
Pages |
127402 |
Keywords |
Editorial; Condensed Matter Theory (CMT) |
Abstract |
In the Comment, the authors state that the separation of the relative and center of mass variables in our work is not correct. Here we point out that there is a typographical error, i.e., qi instead of -e, in two of our equations which, when corrected, makes the Comment redundant. Within the ansatzes mentioned in our paper all our results are correct, in contrast to the claims of the Comment. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000519990800011 |
Publication Date |
2020-03-18 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record |
Impact Factor |
3.7 |
Times cited |
|
Open Access |
|
Notes |
; ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
Call Number |
UA @ admin @ c:irua:167680 |
Serial |
6594 |
Permanent link to this record |
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Author |
Litzius, K.; Leliaert, J.; Bassirian, P.; Rodrigues, D.; Kromin, S.; Lemesh, I.; Zazvorka, J.; Lee, K.-J.; Mulkers, J.; Kerber, N.; Heinze, D.; Keil, N.; Reeve, R.M.; Weigand, M.; Van Waeyenberge, B.; Schuetz, G.; Everschor-Sitte, K.; Beach, G.S.D.; Klaeui, M. |
Title |
The role of temperature and drive current in skyrmion dynamics |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Nature Electronics |
Abbreviated Journal |
|
Volume |
3 |
Issue |
1 |
Pages |
30-36 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Magnetic skyrmions are topologically stabilized nanoscale spin structures that could be of use in the development of future spintronic devices. When a skyrmion is driven by an electric current it propagates at an angle relative to the flow of current-known as the skyrmion Hall angle (SkHA)-that is a function of the drive current. This drive dependence, as well as thermal effects due to Joule heating, could be used to tailor skyrmion trajectories, but are not well understood. Here we report a study of skyrmion dynamics as a function of temperature and drive amplitude. We find that the skyrmion velocity depends strongly on temperature, while the SkHA does not and instead evolves differently in the low- and high-drive regimes. In particular, the maximum skyrmion velocity in ferromagnetic devices is limited by a mechanism based on skyrmion surface tension and deformation (where the skyrmion transitions into a stripe). Our mechanism provides a complete description of the SkHA in ferromagnetic multilayers across the full range of drive strengths, illustrating that skyrmion trajectories can be engineered for device applications. An analysis of skyrmion dynamics at different temperatures and electric drive currents is used to develop a complete description of the skyrmion Hall angle in ferromagnetic multilayers from the creep to the flow regime and illustrates that skyrmion trajectories can be engineered for device applications. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000510860800012 |
Publication Date |
2020-01-24 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
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ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
11 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:167863 |
Serial |
6625 |
Permanent link to this record |
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Author |
Bafekry, A.; Akgenc, B.; Shayesteh, S.F.; Mortazavi, B. |
Title |
Tunable electronic and magnetic properties of graphene/carbon-nitride van der Waals heterostructures |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Applied Surface Science |
Abbreviated Journal |
Appl Surf Sci |
Volume |
505 |
Issue |
|
Pages |
144450-144459 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
In this paper, we explore the electronic properties of C3N, C3N4 and C4N3 and graphene (Gr) van der Waals heterostructures by conducing extensive first-principles calculations. The acquired results show that these heterostructures can show diverse electronic properties, such as the metal (Gr on C3N), semiconductor with narrow band gap (Gr on C3N4) and ferromagnetic-metal (Gr on C4N3). We furthermore explored the effect of vacancies, atom substitution, topological, antisite and Stone-Wales defects on the structural and electronic properties of considered heterostructures. Our results show that the vacancy defects introduce localized states near the Fermi level and create a local magnetic moment. The Gr/C3N heterostructures with the single and double vacancy defects exhibit a ferromagnetic-metal, while Stone-Wales defects show an indirect semiconductor with the band gap of 0.2 eV. The effects of adsorption and insertion of O, C, Be, Cr, Fe and Co atoms on the electronic properties of Gr/C3N have been also elaborately studied. Our results highlight that the electronic and magnetic properties of garphene/carbon-nitride lateral heterostructures can be effectively modified by point defects and impurities. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000510846500052 |
Publication Date |
2019-11-18 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0169-4332 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.7 |
Times cited |
26 |
Open Access |
|
Notes |
; ; |
Approved |
Most recent IF: 6.7; 2020 IF: 3.387 |
Call Number |
UA @ admin @ c:irua:167732 |
Serial |
6638 |
Permanent link to this record |
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Author |
Bafekry, A.; Neek-Amal, M. |
Title |
Tuning the electronic properties of graphene-graphitic carbon nitride heterostructures and heterojunctions by using an electric field |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
Volume |
101 |
Issue |
8 |
Pages |
085417-10 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Integration of graphene-based two-dimensional materials is essential for nanoelectronics applications. Using density-functional theory, we systematically investigate the electronic properties of vertically stacked graphene-graphitic carbon nitrides (GE/GCN). We also studied the covalently lateral stitched graphene-graphitic carbon nitrides (GE-GCN heterojunctions). The effects of perpendicular electric field on the electronic properties of six different heterostructures, i.e., (i) one layer of GE on top of a layer of CnNm with (n, m) = (3,1), (3,4), and (4,3) and (ii) three heterostructures CnNm/Cn'Nm', where (n, m) not equal (n', m') are elucidated. The most important calculated features are (i) the systems GE/C3N4, C3N/C3N4, GE-C3N, GE-C4N3, and C3N-C3N4 exhibit semiconducting characteristics having small band gaps of Delta(0)=20, 250, 100, 100, 80 meV, respectively while (ii) the systems GE/C4N3, C3N/C4N3, and C3N-C4N3 show ferromagnetic-metallic properties. In particular, we found that, in semiconducting heterostructures, the band gap increases nontrivially with increasing the absolute value of the applied perpendicular electric field. This work is useful for designing heterojunctions and heterostructures made of graphene and other two-dimensional materials such as those proposed in recent experiments [X. Liu and M. C. Hersam Sci. Adv. 5, 6444 (2019)]. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000515659700007 |
Publication Date |
2020-02-26 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.7 |
Times cited |
24 |
Open Access |
|
Notes |
; ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
Call Number |
UA @ admin @ c:irua:167760 |
Serial |
6640 |
Permanent link to this record |
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Author |
Bafekry, A.; Neek-Amal, M.; Peeters, F.M. |
Title |
Two-dimensional graphitic carbon nitrides: strain-tunable ferromagnetic ordering |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
Volume |
101 |
Issue |
16 |
Pages |
165407-165408 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Using first-principle calculations, we systematically study strain tuning of the electronic properties of two- dimensional graphitic carbon nitride nanosheets with empirical formula CnNm. We found the following: (i) the ferromagnetic ordered state in the metal-free systems (n, m) = (4,3), (10,9), and (14,12) remains stable in the presence of strain of about 6%. However, the system (9,7) loses its ferromagnetic ordering when increasing strain. This is due to the presence of topological defects in the (9,7) system, which eliminates the asymmetry between spin up and spin down of the p(z) orbitals when strain is applied. (ii) By applying uniaxial strain, a band gap opens in systems which are initially gapless. (iii) In semiconducting systems which have an initial gap of about 1 eV, the band gap is closed with applying uniaxial strain. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000523630200012 |
Publication Date |
2020-04-06 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.7 |
Times cited |
27 |
Open Access |
|
Notes |
; ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
Call Number |
UA @ admin @ c:irua:168560 |
Serial |
6643 |
Permanent link to this record |
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Author |
Obeid, M.M.; Bafekry, A.; Rehman, S.U.; Nguyen, C., V. |
Title |
A type-II GaSe/HfS₂ van der Waals heterostructure as promising photocatalyst with high carrier mobility |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Applied Surface Science |
Abbreviated Journal |
Appl Surf Sci |
Volume |
534 |
Issue |
|
Pages |
147607 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
In this paper, the electronic, optical, and photocatalytic properties of GaSe/HfS2 heterostructure are studied via first-principles calculations. The stability of the vertically stacked heterobilayers is validated by the binding energy, phonon spectrum, and ab initio molecular dynamics simulation. The results reveal that the most stable GaSe/HfS2 heterobilayer retains a type-II alignment with an indirect bandgap 1.40 eV. As well, the results also show strong optical absorption intensity in the studied heterostructure (1.8 x 10(5) cm(-1)). The calculated hole mobility is 1376 cm(2) V-1 s(-1), while electron mobility reaches 911 cm(2) V-1 s(-1) along the armchair and zigzag directions. By applying an external electric field, the bandgap and band offset of the designed heterostructure can be effectively modified. Remarkably, a stronger external electric field can create nearly free electron states in the vicinity of the bottom of the conduction band, which induces indirect-to-direct bandgap transition as well as a semiconductor-to-metal transition. In contrast, the electronic properties of GaSe/HfS2 heterostructure are predicted to be insensitive to biaxial strain. The current work reveals that GaSe/HfS2 heterostructure is a promising candidate as a novel photocatalytic material for hydrogen generation in the visible range. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000582367700045 |
Publication Date |
2020-08-20 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0169-4332 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.7 |
Times cited |
4 |
Open Access |
|
Notes |
; ; |
Approved |
Most recent IF: 6.7; 2020 IF: 3.387 |
Call Number |
UA @ admin @ c:irua:174301 |
Serial |
6682 |
Permanent link to this record |
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Author |
Jalali, H.; Khoeini, F.; Peeters, F.M.; Neek-Amal, M. |
Title |
Hydration effects and negative dielectric constant of nano-confined water between cation intercalated MXenes |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
Volume |
13 |
Issue |
2 |
Pages |
922-929 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
Using electrochemical methods a profound enhancement of the capacitance of electric double layer capacitor electrodes was reported when water molecules are strongly confined into the two-dimensional slits of titanium carbide MXene nanosheets [A. Sugahara et al., Nat. Commun., 2019, 10, 850]. We study the effects of hydration on the dielectric properties of nanoconfined water and supercapacitance properties of the cation intercalated MXene. A model for the electric double layer capacitor is constructed where water molecules are strongly confined in two-dimensional slits of MXene. We report an abnormal dielectric constant and polarization of nano-confined water between MXene layers. We found that by decreasing the ionic radius of the intercalated cations and in a critical hydration shell radius the capacitance of the system increases significantly (similar or equal to 200 F g(-1)) which can be interpreted as a negative permittivity. This study builds a bridge between the fundamental understanding of the dielectric properties of nanoconfined water and the capability of using MXene films for supercapacitor technology, and in doing so provides a solid theoretical support for recent experiments. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000610368100035 |
Publication Date |
2020-12-08 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2040-3364 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
7.367 |
Times cited |
7 |
Open Access |
Not_Open_Access |
Notes |
; ; |
Approved |
Most recent IF: 7.367 |
Call Number |
UA @ admin @ c:irua:176141 |
Serial |
6690 |
Permanent link to this record |
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Author |
Xiao, Y.M.; Xu, W.; Van Duppen, B.; Peeters, F.M. |
Title |
Infrared to terahertz optical conductivity of n-type and p-type monolayer MoS2 in the presence of Rashba spin-orbit coupling |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
Volume |
94 |
Issue |
94 |
Pages |
155432 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We investigate the effect of Rashba spin-orbit coupling (SOC) on the optoelectronic properties of n- and p-type monolayer MoS2. The optical conductivity is calculated within the Kubo formalism. We find that the spin-flip transitions enabled by the Rashba SOC result in a wide absorption window in the optical spectrum. Furthermore, we evaluate the effects of the polarization direction of the radiation, temperature, carrier density, and the strength of the Rashba spin-orbit parameter on the optical conductivity. We find that the position, width, and shape of the absorption peak or absorption window can be tuned by varying these parameters. This study shows that monolayer MoS2 can be a promising tunable optical and optoelectronic material that is active in the infrared to terahertz spectral range. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000386097800003 |
Publication Date |
2016-10-18 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
2469-9950;2469-9969; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
20 |
Open Access |
|
Notes |
; Y.M.X. acknowledges financial support from the China Scholarship Council (CSC). This work was also supported by the National Natural Science Foundation of China (Grant No. 11574319), Ministry of Science and Technology of China (Grant No. 2011YQ130018), Department of Science and Technology of Yunnan Province, and by the Chinese Academy of Sciences. B.V.D. is supported by a Ph.D. fellowship from the Flemish Science Foundation. ; |
Approved |
Most recent IF: 3.836 |
Call Number |
UA @ lucian @ c:irua:138175 |
Serial |
4355 |
Permanent link to this record |
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Author |
Xiao, Y.M.; Xu, W.; Peeters, F.M.; Van Duppen, B. |
Title |
Multicomponent plasmons in monolayer MoS2 with circularly polarized optical pumping |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
Volume |
96 |
Issue |
8 |
Pages |
085405 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
By making use of circularly polarized light and electrostatic gating, monolayer molybdenum disulfide (ML – MoS2) can form a platform supporting multiple types of charge carriers. They can be discriminated by their spin, valley index, or whether they are electrons or holes. We investigate the collective properties of those charge carriers and are able to identify distinct plasmon modes. We analyze the corresponding dispersion relation, lifetime, and oscillator strength, and calculate the phase relation between the oscillations in the different components of the plasmon modes. All platforms in ML-MoS2 support a long-wavelength root q plasmon branch at zero kelvins. In addition to this, for an n-component system, n-1 distinct plasmon modes appear as acoustic modes with linear dispersion in the long-wavelength limit. These modes correspond to out-of-phase oscillations in the different fermion liquids and have, although being damped, a relatively long lifetime. Additionally, we also find distinct modes at large wave vectors that are more strongly damped by intraband processes. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
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Language |
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Wos |
000406861600001 |
Publication Date |
2017-08-04 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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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 |
; Y.M.X. acknowledges financial support from the China Scholarship Council (CSC). B.V.D. is supported by the Flemish Science Foundation (FWO-Vl) through a postdoctoral fellowship. This work was also supported by the National Natural Science Foundation of China (Grants No. 11574319 and No. 11304272), the Ministry of Science and Technology of China (Grant No. 2011YQ130018), the Department of Science and Technology of Yunnan Province, the Applied Basic Research Foundation of Yunnan Province (2013FD003), and the Chinese Academy of Sciences. ; |
Approved |
Most recent IF: 3.836 |
Call Number |
UA @ lucian @ c:irua:145729 |
Serial |
4745 |
Permanent link to this record |
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Author |
Vandenberghe, W.G.; Verhulst, A.S.; Kao, K.-H.; De Meyer, K.; Sorée, B.; Magnus, W.; Groeseneken, G. |
Title |
A model determining optimal doping concentration and material's band gap of tunnel field-effect transistors |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
100 |
Issue |
19 |
Pages |
193509-193509,4 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We develop a model for the tunnel field-effect transistor (TFET) based on the Wentzel-Kramer-Brillouin approximation which improves over existing semi-classical models employing generation rates. We hereby introduce the concept of a characteristic tunneling length in direct semiconductors. Based on the model, we show that a limited density of states results in an optimal doping concentration as well as an optimal material's band gap to obtain the highest TFET on-current at a given supply voltage. The observed optimal-doping trend is confirmed by 2-dimensional quantum-mechanical simulations for silicon and germanium. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4714544] |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000304108000098 |
Publication Date |
2012-05-12 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-6951; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.411 |
Times cited |
25 |
Open Access |
|
Notes |
; William Vandenberghe gratefully acknowledges the support of a Ph.D. stipend from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen). This work was supported by IMEC's Industrial Affiliation Program. ; |
Approved |
Most recent IF: 3.411; 2012 IF: 3.794 |
Call Number |
UA @ lucian @ c:irua:98948 |
Serial |
2105 |
Permanent link to this record |
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Author |
Vandenberghe, W.; Sorée, B.; Magnus, W.; Fischetti, M.V. |
Title |
Generalized phonon-assisted Zener tunneling in indirect semiconductors with non-uniform electric fields : a rigorous approach |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
Volume |
109 |
Issue |
12 |
Pages |
124503-124503,12 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
A general framework to calculate the Zener current in an indirect semiconductor with an externally applied potential is provided. Assuming a parabolic valence and conduction band dispersion, the semiconductor is in equilibrium in the presence of the external field as long as the electron-phonon interaction is absent. The linear response to the electron-phonon interaction results in a non-equilibrium system. The Zener tunneling current is calculated from the number of electrons making the transition from valence to conduction band per unit time. A convenient expression based on the single particle spectral functions is provided, enabling the evaluation of the Zener tunneling current under any three-dimensional potential profile. For a one-dimensional potential profile an analytical expression is obtained for the current in a bulk semiconductor, a semiconductor under uniform field, and a semiconductor under a non-uniform field using the WKB (Wentzel-Kramers-Brillouin) approximation. The obtained results agree with the Kane result in the low field limit. A numerical example for abrupt p-n diodes with different doping concentrations is given, from which it can be seen that the uniform field model is a better approximation than the WKB model, but a direct numerical treatment is required for low bias conditions. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000292331200134 |
Publication Date |
2011-06-21 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
0021-8979; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.068 |
Times cited |
41 |
Open Access |
|
Notes |
; William Vandenberghe gratefully acknowledges the support of a Ph.D. stipend from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen). ; |
Approved |
Most recent IF: 2.068; 2011 IF: 2.168 |
Call Number |
UA @ lucian @ c:irua:90808 |
Serial |
1325 |
Permanent link to this record |
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Author |
Vandenberghe, W.; Sorée, B.; Magnus, W.; Groeseneken, G. |
Title |
Zener tunneling in semiconductors under nonuniform electric fields |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
Volume |
107 |
Issue |
5 |
Pages |
054520,1-054520,7 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Recently, a renewed interest in Zener tunneling has arisen because of its increasing impact on semiconductor device performance at nanometer dimensions. In this paper we evaluate the tunnel probability under the action of a nonuniform electric field using a two-band model and arrive at significant deviations from the commonly used Kanes model, valid for weak uniform fields only. A threshold on the junction bias where Kanes model for Zener tunneling breaks down is determined. Comparison with Kanes model particularly shows that our calculation yields a higher tunnel probability for intermediate electric fields and a lower tunnel probability for high electric fields. When performing a current calculation comparing to the WKB approximation for the case of an abrupt p-n junction significant differences concerning the shape of the I-V curve are demonstrated. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000275657500136 |
Publication Date |
2010-03-11 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0021-8979; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.068 |
Times cited |
22 |
Open Access |
|
Notes |
; William Vandenberghe gratefully acknowledges the support of a Ph. D. stipend from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen). These authors acknowledge the support from IMEC's Industrial Affiliation Program and the authors would like to thank Anne Verhulst for useful comments. ; |
Approved |
Most recent IF: 2.068; 2010 IF: 2.079 |
Call Number |
UA @ lucian @ c:irua:82450 |
Serial |
3929 |
Permanent link to this record |
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Author |
Vandenberghe, W.G.; Verhulst, A.S.; Sorée, B.; Magnus, W.; Groeseneken, G.; Smets, Q.; Heyns, M.; Fischetti, M.V. |
Title |
Figure of merit for and identification of sub-60 mV/decade devices |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
102 |
Issue |
1 |
Pages |
013510-13514 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
A figure of merit I60 is proposed for sub-60 mV/decade devices as the highest current where the input characteristics exhibit a transition from sub- to super-60 mV/decade behavior. For sub-60 mV/decade devices to be competitive with metal-oxide-semiconductor field-effect devices, I60 has to be in the 1-10 μA/μm range. The best experimental tunnel field-effect transistors (TFETs) in the literature only have an I60 of 6×10-3 μA/μm but using theoretical simulations, we show that an I60 of up to 10 μA/μm should be attainable. It is proven that the Schottky barrier FET (SBFET) has a 60 mV/decade subthreshold swing limit while combining a SBFET and a TFET does improve performance. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000313646500132 |
Publication Date |
2013-01-12 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
0003-6951; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.411 |
Times cited |
64 |
Open Access |
|
Notes |
; William G. Vandenberghe gratefully acknowledges the support of a Ph.D. stipend from IWT-Vlaanderen. The authors thank Danielle Leonelli, Lars-Ake Ragnarsson, and Krishna Bhuwalka for useful discussions. This work was supported by imec's Industrial Affiliation Program. ; |
Approved |
Most recent IF: 3.411; 2013 IF: 3.515 |
Call Number |
UA @ lucian @ c:irua:109262 |
Serial |
1192 |
Permanent link to this record |
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Author |
Lozano, D.P.; Couet, S.; Petermann, C.; Hamoir, G.; Jochum, J.K.; Picot, T.; Menendez, E.; Houben, K.; Joly, V.; Antohe, V.A.; Hu, M.Y.; Leu, B.M.; Alatas, A.; Said, A.H.; Roelants, S.; Partoens, B.; Milošević, M.V.; Peeters, F.M.; Piraux, L.; Van de Vondel, J.; Vantomme, A.; Temst, K.; Van Bael, M.J. |
Title |
Experimental observation of electron-phonon coupling enhancement in Sn nanowires caused by phonon confinement effects |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
Volume |
99 |
Issue |
6 |
Pages |
064512 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Reducing the size of a superconductor below its characteristic length scales can either enhance or suppress its critical temperature (T-c). Depending on the bulk value of the electron-phonon coupling strength, electronic and phonon confinement effects will play different roles in the modification of T-c. Experimentally disentangling each contribution has remained a challenge. We have measured both the phonon density of states and T-c of Sn nanowires with diameters of 18, 35, and 100 nm in order to quantify the effects of phonon confinement on superconductivity. We observe a shift of the phonon frequency towards the low-energy region and an increase in the electron-phonon coupling constant that can account for the measured increase in T-c. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000459322400005 |
Publication Date |
2019-02-21 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
11 |
Open Access |
|
Notes |
; We would like to thanks Jeroen Scheerder and Wout Keijers for their help and assistance during the low-temperature measurements. This work was supported by the Research Foundation Flanders (FWO), the Concerted Research Action (GOA/14/ 007), the Federation Wallonie-Bruxelles (ARC 13/18-052, Supracryst) and the Fonds de la Recherche Scientifique -FNRS under Grant No. T.0006.16. The authors acknowledge Hercules Stichting (Project Nos. AKUL/13/19 and AKUL/13/25). D.P.L. thanks the FWO for financial support. This research used resources of the Advanced Photon Source, a US Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. ; |
Approved |
Most recent IF: 3.836 |
Call Number |
UA @ admin @ c:irua:158621 |
Serial |
5212 |
Permanent link to this record |
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Author |
Lukyanchuk, I.; Vinokur, V.M.; Rydh, A.; Xie, R.; Milošević, M.V.; Welp, U.; Zach, M.; Xiao, Z.L.; Crabtree, G.W.; Bending, S.J.; Peeters, F.M.; Kwok, W.K. |
Title |
Rayleigh instability of confined vortex droplets in critical superconductors |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Nature physics |
Abbreviated Journal |
Nat Phys |
Volume |
11 |
Issue |
11 |
Pages |
21-25 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Depending on the Ginzburg-Landau parameter kappa, superconductors can either be fully diamagnetic if kappa < 1/root 2 (type I superconductors) or allow magnetic flux to penetrate through Abrikosov vortices if kappa > 1/root 2 (type II superconductors; refs 1,2). At the Bogomolny critical point, kappa = kappa(c) = 1/root 2, a state that is infinitely degenerate with respect to vortex spatial configurations arises(3,4). Despite in-depth investigations of conventional type I and type II superconductors, a thorough understanding of the magnetic behaviour in the near-Bogomolny critical regime at kappa similar to kappa(c) remains lacking. Here we report that in confined systems the critical regime expands over a finite interval of kappa forming a critical superconducting state. We show that in this state, in a sample with dimensions comparable to the vortex core size, vortices merge into a multi-quanta droplet, which undergoes Rayleigh instability(5) on increasing kappa and decays by emitting single vortices. Superconducting vortices realize Nielsen-Olesen singular solutions of the Abelian Higgs model, which is pervasive in phenomena ranging from quantum electrodynamics to cosmology(6-9). Our study of the transient dynamics of Abrikosov-Nielsen-Olesen vortices in systems with boundaries promises access to non-trivial effects in quantum field theory by means of bench-top laboratory experiments. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000346831100018 |
Publication Date |
2014-11-06 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
1745-2473;1745-2481; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
22.806 |
Times cited |
20 |
Open Access |
|
Notes |
; We would like to thank N. Nekrasov for illuminating discussions. The work was supported by the US Department of Energy, Office of Science Materials Sciences and Engineering Division (V.M.V., W.K.K., U.W., R.X., M.Z., Z.L.X., G.W.C. and partially I.L. through the Materials Theory Institute), by FP7-IRSES-SIMTECH and ITN-NOTEDEV programs (I.L.), and by the Flemish Science Foundation (FWO-Vlaanderen) (M.V.M. and F.M.P.). ; |
Approved |
Most recent IF: 22.806; 2015 IF: 20.147 |
Call Number |
c:irua:122791 c:irua:122791 |
Serial |
2815 |
Permanent link to this record |
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Author |
Embon, L.; Anahory, Y.; Jelić, Z.L.; Lachman, E.O.; Myasoedov, Y.; Huber, M.E.; Mikitik, G.P.; Silhanek, A.V.; Milošević, M.V.; Gurevich, A.; Zeldov, E. |
Title |
Imaging of super-fast dynamics and flow instabilities of superconducting vortices |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
8 |
Issue |
|
Pages |
85 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
Quantized magnetic vortices driven by electric current determine key electromagnetic properties of superconductors. While the dynamic behavior of slow vortices has been thoroughly investigated, the physics of ultrafast vortices under strong currents remains largely unexplored. Here, we use a nanoscale scanning superconducting quantum interference device to image vortices penetrating into a superconducting Pb film at rates of tens of GHz and moving with velocities of up to tens of km/s, which are not only much larger than the speed of sound but also exceed the pair-breaking speed limit of superconducting condensate. These experiments reveal formation of mesoscopic vortex channels which undergo cascades of bifurcations as the current and magnetic field increase. Our numerical simulations predict metamorphosis of fast Abrikosov vortices into mixed Abrikosov-Josephson vortices at even higher velocities. This work offers an insight into the fundamental physics of dynamic vortex states of superconductors at high current densities, crucial for many applications. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000405900400002 |
Publication Date |
2017-07-13 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2041-1723 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
124 |
Open Access |
|
Notes |
; We would like to thank M.L. Rappaport for fruitful discussions and technical support. This work was supported by the US-Israel Binational Science Foundation (BSF) grant No. 2014155 and the Israel Science Foundation grant No. 132/14. A.G. was also supported by the United States Department of Energy under Grant No. DE-SC0010081. M.V.M. acknowledges support from Research Foundation-Flanders (FWO). The work of Z.L.J. and A.V.S. was partially supported by “Mandat d'Impulsion Scientifique” MIS F.4527.13 of the F.R.S.-FNRS. This work benefited from the support of COST action MP-1201. ; |
Approved |
Most recent IF: 12.124 |
Call Number |
UA @ lucian @ c:irua:144832 |
Serial |
4720 |
Permanent link to this record |
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Author |
Beheshtian, J.; Sadeghi, A.; Neek-Amal, M.; Michel, K.H.; Peeters, F.M. |
Title |
Induced polarization and electronic properties of carbon-doped boron nitride nanoribbons |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
86 |
Issue |
19 |
Pages |
195433-195438 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The electronic properties of boron nitride nanoribbons (BNNRs) doped with a line of carbon atoms are investigated using density functional calculations. By replacing a line of alternating B and N atoms with carbons, three different configurations are possible depending on the type of the atoms which bond to the carbons. We found very different electronic properties for these configurations: (i) the NCB arrangement is strongly polarized with a large dipole moment having an unexpected direction, (ii) the BCB and NCN arrangements are nonpolar with zero dipole moment, (iii) the doping by a carbon line reduces the band gap regardless of the local arrangement of the borons and the nitrogens around the carbon line, and (iv) the polarization and energy gap of the carbon-doped BNNRs can be tuned by an electric field applied parallel to the carbon line. Similar effects were found when either an armchair or zigzag line of carbon was introduced. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000311694200006 |
Publication Date |
2012-11-29 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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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 |
; We would like to thank J. M. Pereira and S. Goedecker for helpful discussions. This work was supported by the Flemish Science Foundation (FWO-Vl), the ESF-EuroGRAPHENE project CONGRAN. M. N.-A is supported by EU-Marie Curie IIF postdoc Fellowship/299522. ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
Call Number |
UA @ lucian @ c:irua:105136 |
Serial |
1603 |
Permanent link to this record |
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Author |
Oueslati, S.; Brammertz, G.; Buffiere, M.; ElAnzeery, H.; Touayar, O.; Koeble, C.; Bekaert, J.; Meuris, M.; Poortmans, J. |
Title |
Physical and electrical characterization of high-performance Cu2ZnSnSe4 based thin film solar cells |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Thin solid films : an international journal on the science and technology of thin and thick films |
Abbreviated Journal |
Thin Solid Films |
Volume |
582 |
Issue |
582 |
Pages |
224-228 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We report on the electrical, optical and physical properties of Cu2ZnSnSe4 solar cells using an absorber layer fabricated by selenization of sputtered Cu, Zn and Cu10Sn90 multilayers. A maximum active-area conversion efficiency of 10.4% under AM1.5G was measured with a maximum short circuit current density of 39.7 mA/cm(2), an open circuit voltage of 394 mV and a fill factor of 66.4%. We perform electrical and optical characterization using photoluminescence spectroscopy, external quantum efficiency, current-voltage and admittance versus temperature measurements in order to derive information about possible causes for the low open circuit voltage values observed. The main defects derived from these measurements are strong potential fluctuations in the absorber layer as well as a potential barrier of the order of 133 meV at the back side contact. (C) 2014 Elsevier B.V. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lausanne |
Editor |
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Language |
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Wos |
000352225900048 |
Publication Date |
2014-10-20 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0040-6090 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.879 |
Times cited |
49 |
Open Access |
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Notes |
; We would like to acknowledge Tom De Geyter, Greetje Godiers, and Guido Huyberechts from Flamac in Gent for sputtering of the metal layers. AGC is acknowledged for providing substrates. This research is partially funded by the Flemish government, Department Economy, Science and Innovation. ; |
Approved |
Most recent IF: 1.879; 2015 IF: 1.759 |
Call Number |
UA @ lucian @ c:irua:132504 |
Serial |
4225 |
Permanent link to this record |
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Author |
Branchaud, S.; Kam, A.; Zawadzki, P.; Peeters, F.M.; Sachrajda, A.S. |
Title |
Transport detection of quantum Hall fluctuations in graphene |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
81 |
Issue |
12 |
Pages |
121406,1-121406,4 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Low-temperature magnetoconductance measurements were made in the vicinity of the charge neutrality point (CNP). Two origins for the fluctuations were identified close to the CNP. At very low magnetic fields there exist only mesoscopic magnetoconductance quantum interference features which develop rapidly as a function of density. At slightly higher fields (>0.5 T), close to the CNP, additional fluctuations track the quantum Hall (QH) sequence expected for monolayer graphene. These additional features are attributed to effects of locally charging individual QH localized states. These effects reveal a precursor to the quantum Hall effect since, unlike previous transport observations of QH dot charging effects, they occur in the absence of quantum Hall plateaus or Shubnikov-de Haas oscillations. From our transport data we are able to extract parameters that characterize the inhomogeneities in our device. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000276248900026 |
Publication Date |
2010-03-09 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
25 |
Open Access |
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Notes |
; We would like to acknowledge important motivating discussions with Louis Gaudreau, Ghislain Granger, Pawel Hawrylak, Devrim Guclu, Josh Folk, and Mark Lundeberg. A. S. S. and F. M. P. acknowledge funding from CIFAR. A. S. S. and S. B. acknowledge assistance from NSERC. ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
Call Number |
UA @ lucian @ c:irua:82275 |
Serial |
3723 |
Permanent link to this record |
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Author |
Peymanirad, F.; Singh, S.K.; Ghorbanfekr-Kalashami, H.; Novoselov, K.S.; Peeters, F.M.; Neek-Amal, M. |
Title |
Thermal activated rotation of graphene flake on graphene |
Type |
A1 Journal article |
Year |
2017 |
Publication |
2D materials |
Abbreviated Journal |
2D Mater |
Volume |
4 |
Issue |
2 |
Pages |
025015 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The self rotation of a graphene flake over graphite is controlled by the size, initial misalignment and temperature. Using both ab initio calculations and molecular dynamics simulations, we investigate annealing effects on the self rotation of a graphene flake on a graphene substrate. The energy barriers for rotation and drift of a graphene flake over graphene is found to be smaller than 25 meV/atom which is comparable to thermal energy. We found that small flakes (of about similar to 4 nm) are more sensitive to temperature and initial misorientation angles than larger one (beyond 10 nm). The initial stacking configuration of the flake is found to be important for its dynamics and time evolution of misalignment. Large flakes, which are initially in the AA-or AB-stacking state with small misorientation angle, rotate and end up in the AB-stacking configuration. However small flakes can they stay in an incommensurate state specially when the initial misorientation angle is larger than 2 degrees. Our results are in agreement with recent experiments. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
IOP Publishing |
Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000424399600005 |
Publication Date |
2017-02-02 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2053-1583 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.937 |
Times cited |
16 |
Open Access |
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Notes |
; We would like to acknowledge Annalisa Fasolino and MM van Wijk for providing us with the implemented parameters of REBO-KC [5] in LAMMPS. This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation. ; |
Approved |
Most recent IF: 6.937 |
Call Number |
UA @ lucian @ c:irua:149364 |
Serial |
4984 |
Permanent link to this record |
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Author |
Madan, I.; Kusar, P.; Baranov, V.V.; Lu-Dac, M.; Kabanov, V.V.; Mertelj, T.; Mihailovic, D. |
Title |
Real-time measurement of the emergence of superconducting order in a high-temperature superconductor |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
Volume |
93 |
Issue |
22 |
Pages |
224520 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Systems which rapidly evolve through symmetry-breaking transitions on timescales comparable to the fluctuation timescale of the single-particle excitations may behave very differently than under controlled near-ergodic conditions. A real-time investigation with high temporal resolution may reveal insights into the ordering through the transition that are not available in static experiments. We present an investigation of the system trajectory through a normal-to-superconductor transition in a prototype high-temperature superconducting cuprate in which such a situation occurs. Using a multiple pulse femtosecond spectroscopy technique we measure the system trajectory and time evolution of the single-particle excitations through the transition in La1.9Sr0.1CuO4 and compare the data to a simulation based on the time-dependent Ginzburg-Landau theory, using the laser excitation fluence as an adjustable parameter controlling the quench conditions in both experiment and theory. The comparison reveals the presence of significant superconducting fluctuations which precede the transition on short timescales. By including superconducting fluctuations as a seed for the growth of the superconducting order we can obtain a satisfactory agreement of the theory with the experiment. Remarkably, the pseudogap excitations apparently play no role in this process. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
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Language |
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Wos |
000378815800003 |
Publication Date |
2016-07-01 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
5 |
Open Access |
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Notes |
; We wish to acknowledge the useful discussion with T. W. Kibble regarding the importance of a variable quench rate in the experiment. The funding was provided by European Research Council advanced grant TRAJECTORY. ; |
Approved |
Most recent IF: 3.836 |
Call Number |
UA @ lucian @ c:irua:144701 |
Serial |
4683 |
Permanent link to this record |
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Author |
Pereira, J.M.; Peeters, F.M.; Chaves, A.; Farias, G.A. |
Title |
Klein tunneling in single and multiple barriers in graphene |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Semiconductor science and technology |
Abbreviated Journal |
Semicond Sci Tech |
Volume |
25 |
Issue |
3 |
Pages |
033002,1-033002,9 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We review the transmission properties of carriers interacting with potential barriers in graphene. The tunneling of electrons and holes in quantum structures in graphene is found to display features that are in marked contrast with those of other systems. In particular, the interaction between the carriers with electrostatic potential barriers can be related to the propagation of electromagnetic waves in media with negative refraction indices, also known as metamaterials. This behavior becomes evident as one calculates the time evolution of wavepackets propagating across the barrier interface. In addition, we discuss the effect of trigonal warping on the tunneling through potential barriers. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000274318300004 |
Publication Date |
2010-02-04 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0268-1242;1361-6641; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.305 |
Times cited |
83 |
Open Access |
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Notes |
; We want to acknowledge our collaborators in this work: P Vasilopoulos and M Barbier. This work was supported by the Brazilian Council for Research (CNPq), the Flemish Science Foundation (FWO-Vl) and the Belgian Science Policy (IAP). ; |
Approved |
Most recent IF: 2.305; 2010 IF: 1.333 |
Call Number |
UA @ lucian @ c:irua:80961 |
Serial |
1764 |
Permanent link to this record |
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Author |
Goncalves, W.C.; Sardella, E.; Becerra, V.F.; Milošević, M.V.; Peeters, F.M. |
Title |
Numerical solution of the time dependent Ginzburg-Landau equations for mixed (d plus s)-wave superconductors |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Journal of mathematical physics |
Abbreviated Journal |
J Math Phys |
Volume |
55 |
Issue |
4 |
Pages |
041501 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The time-dependent Ginzburg-Landau formalism for (d + s)-wave superconductors and their representation using auxiliary fields is investigated. By using the link variable method, we then develop suitable discretization of these equations. Numerical simulations are carried out for a mesoscopic superconductor in a homogeneous perpendicular magnetic field which revealed peculiar vortex states. (C) 2014 AIP Publishing LLC. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000336084100001 |
Publication Date |
2014-04-16 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0022-2488;1089-7658; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.077 |
Times cited |
6 |
Open Access |
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Notes |
; We thank the Brazilian Agency FAPESP and Flemish Science Foundation (FSF) (FWO-Vlaanderen) for financial support. M. V. M. acknowledges support from the CAPES-PVE program. ; |
Approved |
Most recent IF: 1.077; 2014 IF: 1.243 |
Call Number |
UA @ lucian @ c:irua:117728 |
Serial |
2407 |
Permanent link to this record |
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Author |
Chen, X.; Bouhon, A.; Li, L.; Peeters, F.M.; Sanyal, B. |
Title |
PAI-graphene : a new topological semimetallic two-dimensional carbon allotrope with highly tunable anisotropic Dirac cones |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Carbon |
Abbreviated Journal |
Carbon |
Volume |
170 |
Issue |
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Pages |
477-486 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Using evolutionary algorithm for crystal structure prediction, we present a new stable two-dimensional (2D) carbon allotrope composed of polymerized as-indacenes (PAI) in a zigzag pattern, namely PAI-graphene whose energy is lower than most of the reported 2D allotropes of graphene. Crucially, the crystal structure realizes a nonsymmorphic layer group that enforces a nontrivial global topology of the band structure with two Dirac cones lying perfectly at the Fermi level. The absence of electron/hole pockets makes PAI-graphene a pristine crystalline topological semimetal having anisotropic Fermi velocities with a high value of 7.0 x 10(5) m/s. We show that while the semimetallic property of the allotrope is robust against the application of strain, the positions of the Dirac cone and the Fermi velocities can be modified significantly with strain. Moreover, by combining strain along both the x- and y-directions, two band inversions take place at G leading to the annihilation of the Dirac nodes demonstrating the possibility of strain-controlled conversion of a topological semimetal into a semiconductor. Finally we formulate the bulk-boundary correspondence of the topological nodal phase in the form of a generalized Zak-phase argument finding a perfect agreement with the topological edge states computed for different edge-terminations. (C) 2020 The Author(s). Published by Elsevier Ltd. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000579779800047 |
Publication Date |
2020-08-21 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0008-6223 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
10.9 |
Times cited |
43 |
Open Access |
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Notes |
; We thank S. Nahas, for helpful discussions. This work is supported by the project grant (2016e05366) and Swedish Research Links program grant (2017e05447) from the Swedish Research Council, the Fonds voor Wetenschappelijk Onderzoek (FWO-Vl), the FLAG-ERA project TRANS 2D TMD. Linyang Li acknowledges financial support from the Natural Science Foundation of Hebei Province (Grant No. A2020202031). X.C. thanks China scholarship council for financial support (No. 201606220031). X.C. and B.S. acknowledge SNIC-UPPMAX, SNIC-HPC2N, and SNIC-NSC centers under the Swedish National Infrastructure for Computing (SNIC) resources for the allocation of time in high-performance supercomputers. Moreover, supercomputing resources from PRACE DECI-15 project DYNAMAT are gratefully acknowledged. ; |
Approved |
Most recent IF: 10.9; 2020 IF: 6.337 |
Call Number |
UA @ admin @ c:irua:173513 |
Serial |
6577 |
Permanent link to this record |
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Author |
Van Duppen, B.; Peeters, F.M. |
Title |
Klein paradox for a pn junction in multilayer graphene |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Europhysics letters |
Abbreviated Journal |
Epl-Europhys Lett |
Volume |
102 |
Issue |
2 |
Pages |
27001-27005 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Charge carriers in single and multilayered graphene systems behave as chiral particles due to the particular lattice symmetry of the crystal. We show that the interplay between the meta-material properties of graphene multilayers and the pseudospinorial properties of the charge carriers result in the occurrence of Klein and anti-Klein tunneling for rhombohedral stacked multilayers. We derive an algebraic formula predicting the angles at which these phenomena occur and support this with numerical calculations for systems up to four layers. We present a decomposition of an arbitrarily stacked multilayer into pseudospin doublets that have the same properties as rhombohedral systems with a lower number of layers. Copyright (C) EPLA, 2013 |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Paris |
Editor |
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Language |
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Wos |
000319617700017 |
Publication Date |
2013-05-02 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0295-5075;1286-4854; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.957 |
Times cited |
17 |
Open Access |
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Notes |
; We thank S. GILLIS for valuable discussions. This work was supported by the European Science Foundation (ESF) under the EUROCORES Program Euro-GRAPHENE within the project CONGRAN, the Flemish Science Foundation (FWO-Vl) by an aspirant research grant to B. Van Duppen and the Methusalem Programme of the Flemish Government. ; |
Approved |
Most recent IF: 1.957; 2013 IF: 2.269 |
Call Number |
UA @ lucian @ c:irua:109665 |
Serial |
1763 |
Permanent link to this record |