Records |
Author |
Mirzakhani, M.; da Costa, D.R.; Peeters, F.M. |
Title |
Isolated and hybrid bilayer graphene quantum rings |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
Volume |
105 |
Issue |
11 |
Pages |
115430-11 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Using the continuum model, we investigate the electronic properties of two types of bilayer graphene (BLG) quantum ring (QR) geometries: (i) An isolated BLG QR and (ii) a monolayer graphene (MLG) with a QR put on top of an infinite graphene sheet (hybrid BLG QR). Solving the Dirac-Weyl equation in the presence of a perpendicular magnetic field and applying the infinite mass boundary condition at the ring boundaries, we obtain analytical results for the energy levels and corresponding wave spinors for both structures. In the case of isolated BLG QR, we observe a sizable and magnetically tunable band gap which agrees with the tight-binding transport simulations. Our analytical results also show the intervalley symmetry EeK (m) = ???EK??? h (m) between the electron (e) and the hole (h) states (m is the angular momentum quantum number) for the energy spectrum of the isolated BLG QR. The presence of interface boundary in a hybrid BLG QR modifies drastically the energy levels as compared with that of an isolated BLG QR. Its energy levels are tunable from MLG dot to isolated BLG QR and to MLG Landau energy levels as the magnetic field is varied. Our predictions can be verified experimentally using different techniques such as by magnetotransport measurements. |
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 |
000801209300006 |
Publication Date |
2022-03-28 |
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 |
|
Additional Links ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.7 |
Times cited |
4 |
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 3.7 |
Call Number |
UA @ admin @ c:irua:188703 |
Serial |
7175 |
Permanent link to this record |
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Author |
Berdiyorov, G.R.; Peeters, F.M.; Hamoudi, H. |
Title |
Effect of edge groups on the electronic transport properties of tetrapodal diazatriptycene molecule |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Physica. E: Low-dimensional systems and nanostructures |
Abbreviated Journal |
Physica E |
Volume |
141 |
Issue |
|
Pages |
115212-115216 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
We conduct ballistic transport calculations to study the electronic transport properties of diazatriptycene molecule which can be self-assembled on metallic surfaces with uniform coverage and upright orientation of the functional head group. Due to its structural asymmetry, the molecule shows a clear current rectification, where the level of the rectification depends on the nature of the head group. For example, current rectification can be increased by more than a factor of 2 by anchoring the molecules to the electrode by CN functional group or introducing insulating CH2 group between the thiol end group and the adjacent phenyl ring. Our findings show the possibility of creating self-assembled monolayer of DAT molecules with controlled electronic transport properties through functionalization of the head group. |
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 |
000806548600006 |
Publication Date |
2022-03-04 |
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 |
1386-9477 |
ISBN |
|
Additional Links ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.3 |
Times cited |
2 |
Open Access |
Not_Open_Access |
Notes |
|
Approved |
Most recent IF: 3.3 |
Call Number |
UA @ admin @ c:irua:189041 |
Serial |
7147 |
Permanent link to this record |
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Author |
Magalhães Cunha, S. |
Title |
Wave-packet dynamics and electronic transport properties in 2D materials |
Type |
Doctoral thesis |
Year |
2022 |
Publication |
|
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
219 p. |
Keywords |
Doctoral thesis; Condensed Matter Theory (CMT) |
Abstract |
This piece of work is twofold. First, the time evolution of wave-packets in 2D systems is analyzed by the Split-Operator technique in three different scenarios: in multilayer phosphorene, the transient oscillations in the time-dependent average of position and momentum were observed due to the zitterbewegung effect, and the wave packet propagates non-uniformly along the space deforming itself into an elliptical shape. These results were corroborated by the Green’s function formalism except for large values of the wave-vector and long times; in 2D semiconductor quantum wires (QWs) with anisotropic effective masses and different angle orientations with respect to the anisotropic axis. We have shown that the greater this angle, the smaller is the energy levels spacing implying in an increase of the accessible electronic states. Additionally, for non-null magnetic field, the quantum Hall edge states are significantly affected by the edge orientation. In the anisotropic case damped oscillations in the average values of velocity in both x and y directions where obtained. Theses oscillations are originated by the QW geometry but also from subwavepackets with different momentum orientations, whereas for isotropic QWs the wavepacket disperses without splitting; in the third scenario the split-operator technique was used to study the Landau levels, the wave packet trajectories and velocities of electrons in graphene at low-energy regime described by a modified Dirac equation where the momentum-operator is written in a generalized form as result of applying the position-dependent translation operator formalism (PDTO). In the second part of this thesis, the electronic and tunneling properties of α − T3 lattices were studied. Electrons in these lattices behave analogous to integer-spin Dirac Fermions. The presence of a third atomic site in the unit cell leads to a flat band in the energy spectrum, providing unique electronic and tunneling properties. The presence of a super-periodic potential and the inclusion of symmetry-breaking terms results in deviations of the atomic equivalence between the atomic sites affecting the Dirac points and the band-gap. Small deviations in the equivalence between the atomic sites and the number of barriers change the transmission properties in these lattices. Additionally, new tunneling regions are possible by adjusting the symmetry between the atomic sites and affect the omnidirectional total transmission called super-Klein tunneling observed in these lattices. We compare those results to the tunneling probabilities through regions where the energy spectrum changes from linear with a middle flat band to a hyperbolic dispersion. |
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Editor |
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Wos |
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Publication Date |
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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 ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
UA library record |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:189191 |
Serial |
7227 |
Permanent link to this record |
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Author |
Gogoi, A.; Neyts, E.C.; Milošević, M.V.; Peeters, F.M. |
Title |
Arresting aqueous swelling of layered graphene-oxide membranes with H3O+ and OH- ions |
Type |
A1 Journal article |
Year |
2022 |
Publication |
ACS applied materials and interfaces |
Abbreviated Journal |
Acs Appl Mater Inter |
Volume |
14 |
Issue |
30 |
Pages |
34946-34954 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
Over the past decade, graphene oxide (GO) has emerged as a promising membrane material with superior separation performance and intriguing mechanical/chemical stability. However, its practical implementation remains very challenging primarily because of its undesirable swelling in an aqueous environment. Here, we demonstrated that dissociation of water molecules into H3O+ and OH- ions inside the interlayer gallery of a layered GO membrane can strongly affect its stability and performance. We reveal that H3O+ and OH- ions form clusters inside the GO laminates that impede the permeance of water and salt ions through the membrane. Dynamics of those clusters is sensitive to an external ac electric field, which can be used to tailor the membrane performance. The presence of H3O+ and OH- ions also leads to increased stability of the hydrogen bond (H-bond) network among the water molecules and the GO layers, which further reduces water permeance through the membrane, while crucially imparting stability to the layered GO membrane against undesirable swelling. KEYWORDS: layered graphene-oxide membrane, aqueous stability, H3O+ and OH- ions, external electric field, molecular dynamics |
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 |
000835946500001 |
Publication Date |
2022-07-25 |
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 |
|
Edition |
|
ISSN |
1944-8244 |
ISBN |
|
Additional Links ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.5 |
Times cited |
9 |
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 9.5 |
Call Number |
UA @ admin @ c:irua:189467 |
Serial |
7127 |
Permanent link to this record |
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Author |
Achari, A.; Bekaert, J.; Sreepal, V.; Orekhov, A.; Kumaravadivel, P.; Kim, M.; Gauquelin, N.; Pillai, P.B.; Verbeeck, J.; Peeters, F.M.; Geim, A.K.; Milošević, M.V.; Nair, R.R. |
Title |
Alternating superconducting and charge density wave monolayers within bulk 6R-TaS₂ |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Nano letters |
Abbreviated Journal |
Nano Lett |
Volume |
22 |
Issue |
15 |
Pages |
6268-6275 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
Abstract |
Van der Waals (vdW) heterostructures continue to attract intense interest as a route of designing materials with novel properties that cannot be found in nature. Unfortunately, this approach is currently limited to only a few layers that can be stacked on top of each other. Here, we report a bulk vdW material consisting of superconducting 1H TaS2 monolayers interlayered with 1T TaS2 monolayers displaying charge density waves (CDW). This bulk vdW heterostructure is created by phase transition of 1T-TaS2 to 6R at 800 degrees C in an inert atmosphere. Its superconducting transition (T-c) is found at 2.6 K, exceeding the T-c of the bulk 2H phase. Using first-principles calculations, we argue that the coexistence of superconductivity and CDW within 6R-TaS2 stems from amalgamation of the properties of adjacent 1H and 1T monolayers, where the former dominates the superconducting state and the latter the CDW behavior. |
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 |
000831832100001 |
Publication Date |
2022-07-20 |
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 |
1530-6984 |
ISBN |
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Additional Links ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
10.8 |
Times cited |
12 |
Open Access |
OpenAccess |
Notes |
This work was supported by the Royal Society, the Leverhulme Trust (PLP-2018-220), the Engineering and Physical Sciences Research Council (EP/N005082/1), and European Research Council (contract 679689). The authors acknowledge the use of the facilities at the Henry Royce Institute and associated support services. J.B. is a postdoctoral fellow of Research Foundation-Flanders (FWO-Vlaanderen). Computational resources were provided by the VSC (Flemish Supercomputer Center), funded by the FWO and the Flemish Governmentdepartment EWI. This work was also performed under a transnational access provision funded by the European Union under the Horizon 2020 programme within a contract for Integrating Activities for Advanced Communities No 823717 − ESTEEM3; esteem3reported; esteem3jra |
Approved |
Most recent IF: 10.8 |
Call Number |
UA @ admin @ c:irua:189495 |
Serial |
7077 |
Permanent link to this record |
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Author |
Shafiei, M.; Fazileh, F.; Peeters, F.M.; Milošević, M.V. |
Title |
Axion insulator states in a topological insulator proximitized to magnetic insulators : a tight-binding characterization |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Physical review materials |
Abbreviated Journal |
|
Volume |
6 |
Issue |
7 |
Pages |
074205-74208 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The recent discovery of axion states in materials such as antiferromagnetic topological insulators has boosted investigations of the magnetoelectric response in topological insulators and their promise towards realizing dissipationless topological electronics. In this paper, we develop a tight-binding methodology to explore the emergence of axion states in Bi2Se3 in proximity to magnetic insulators on the top and bottom surfaces. The topological protection of the surface states is lifted by a time-reversal-breaking perturbation due to the proximity of a magnetic insulator, and a gap is opened on the surfaces, giving rise to half-quantized Hall conductance and a zero Hall plateau-evidencing an axion insulator state. We developed a real-space tight-binding Hamiltonian for Bi2Se3 using first-principles data. Transport properties of the system were obtained within the Landauer-Buttiker formalism, and we discuss the creation of axion states through Hall conductance and a zero Hall plateau at the surfaces, as a function of proximitized magnetization and corresponding potentials at the surfaces, as well as the thickness of the topological insulator. |
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 |
000832387000006 |
Publication Date |
2022-07-21 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition |
|
ISSN |
2475-9953 |
ISBN |
|
Additional Links ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.4 |
Times cited |
4 |
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 3.4 |
Call Number |
UA @ admin @ c:irua:189498 |
Serial |
7130 |
Permanent link to this record |
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Author |
Abedi, S.; Sisakht, E.T.; Hashemifar, S.J.; Cherati, N.G.; Sarsari, I.A.; Peeters, F.M. |
Title |
Prediction of novel two-dimensional Dirac nodal line semimetals in Al₂B₂ and AlB₄ monolayers |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
Volume |
14 |
Issue |
31 |
Pages |
11270-11283 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
Topological semimetal phases in two-dimensional (2D) materials have gained widespread interest due to their potential applications in novel nanoscale devices. Despite the growing number of studies on 2D topological nodal lines (NLs), candidates with significant topological features that combine nontrivial topological semimetal phase with superconductivity are still rare. Herein, we predict Al2B2 and AlB4 monolayers as new 2D nonmagnetic Dirac nodal line semimetals with several novel features. Our extensive electronic structure calculations combined with analytical studies reveal that, in addition to multiple Dirac points, these 2D configurations host various highly dispersed NLs around the Fermi level, all of which are semimetal states protected by time-reversal and in-plane mirror symmetries. The most intriguing NL in Al2B2 encloses the K point and crosses the Fermi level, showing a considerable dispersion and thus providing a fresh playground to explore exotic properties in dispersive Dirac nodal lines. More strikingly, for the AlB4 monolayer, we provide the first evidence for a set of 2D nonmagnetic open type-II NLs coexisting with superconductivity at a rather high transition temperature. The coexistence of superconductivity and nontrivial band topology in AlB4 not only makes it a promising material to exhibit novel topological superconducting phases, but also a rather large energy dispersion of type-II nodal lines in this configuration may offer a platform for the realization of novel topological features in the 2D limit. |
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 |
000831003900001 |
Publication Date |
2022-06-20 |
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 |
|
ISSN |
2040-3364; 2040-3372 |
ISBN |
|
Additional Links ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
UA library record; WoS full record |
Impact Factor |
6.7 |
Times cited |
5 |
Open Access |
Not_Open_Access |
Notes |
|
Approved |
Most recent IF: 6.7 |
Call Number |
UA @ admin @ c:irua:189505 |
Serial |
7196 |
Permanent link to this record |
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Author |
Shafiei, M.; Fazileh, F.; Peeters, F.M.; Milošević, M.V. |
Title |
Controlling the hybridization gap and transport in a thin-film topological insulator : effect of strain, and electric and magnetic field |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
Volume |
106 |
Issue |
3 |
Pages |
035119-7 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
In a thin-film topological insulator (TI), the edge states on two surfaces may couple by quantum tunneling, opening a gap known as the hybridization gap. Controlling the hybridization gap and transport has a variety of potential uses in photodetection and energy-harvesting applications. In this paper, we report the effect of strain, and electric and magnetic field, on the hybridization gap and transport in a thin Bi2Se3 film, investigated within the tight-binding theoretical framework. We demonstrate that vertical compression decreases the hybridization gap, as does tensile in-plane strain. Applying an electric field breaks the inversion symmetry and leads to a Rashba-like spin splitting proportional to the electric field, hence closing and reopening the gap. The influence of a magnetic field on thin-film TI is also discussed, starting from the role of an out-of-plane magnetic field on quantum Hall states. We further demonstrate that the hybridization gap can be controlled by an in-plane magnetic field, and that by applying a sufficiently strong field a quantum phase transition from an insulator to a semimetal can be achieved. |
Address |
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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 |
000832277500001 |
Publication Date |
2022-07-13 |
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 |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.7 |
Times cited |
7 |
Open Access |
Not_Open_Access |
Notes |
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Approved |
Most recent IF: 3.7 |
Call Number |
UA @ admin @ c:irua:189515 |
Serial |
7140 |
Permanent link to this record |
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Author |
Moura, V.N.; Dantas, D.S.; Farias, G.A.; Chaves, A.; Milošević, M.V. |
Title |
Latent superconductivity at parallel interfaces in a superlattice dominated by another collective quantum phase |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
Volume |
106 |
Issue |
1 |
Pages |
014516-10 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We theoretically examine behavior of superconductivity at parallel interfaces separating the domains of another dominant collective excitation, such as charge density waves or spin density waves. Due to their competitive coupling in a two-component Ginzburg-Landau model, suppression of the dominant order parameter at the interfacial planes allows for nucleation of the (hidden) superconducting order parameter at those planes. In such a case, we demonstrate how the number of the parallel interfacial planes and the distance between them are linked to the number and the size of the emerging superconducting gaps in the system, as well as the versatility and temperature evolution of the possible superconducting phases. These findings bear relevance to a broad selection of known layered superconducting materials, as well as to further design of artificial (e.g., oxide) superlattices, where the interplay between competing order parameters paves the way towards otherwise unattainable superconducting states, some with enhanced superconducting critical temperature. |
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Place of Publication |
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Language |
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Wos |
000834346000004 |
Publication Date |
2022-07-22 |
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 ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
UA library record; WoS full record |
Impact Factor |
3.7 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
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Approved |
Most recent IF: 3.7 |
Call Number |
UA @ admin @ c:irua:189520 |
Serial |
7179 |
Permanent link to this record |
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Author |
Dobrota, A.S.; Vlahovic, J.; V. Skorodumova, N.; Pasti, I.A. |
Title |
First-principles analysis of aluminium interaction with nitrogen-doped graphene nanoribbons – from adatom bonding to various |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Materials Today Communications |
Abbreviated Journal |
|
Volume |
31 |
Issue |
|
Pages |
103388-10 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Enhancing aluminium interaction with graphene-based materials is of crucial importance for the development of Al-storage materials and novel functional materials via atomically precise doping. Here, DFT calculations are employed to investigate Al interactions with non-doped and N-doped graphene nanoribbons (GNRs) and address the impact of the edge sites and N-containing defects on the material's reactivity towards Al. The presence of edges does not influence the energetics of Al adsorption significantly (compared to pristine graphene sheet). On the other hand, N-doping of graphene nanoribbons is found to affect the adsorption energy of Al to an extent that strongly depends on the type of N-containing defect. The introduction of edge-NO group and doping with in -plane pyridinic N result in Al adsorption nearly twice as strong as on pristine graphene. Moreover, double n-type doping via N and Al significantly alters the electronic structure of Al,N-containing GNRs. Our results suggest that selectively doped GNRs with pyridinic N can have enhanced Al-storage capacity and could be potentially used for selective Al electrosorption and removal. On the other hand, Al,N-containing GNRs with pyridinic N could also be used in resistive sensors for mechanical deformation. Namely, strain along the longitudinal axis of these dual doped GNRs does not affect the binding of Al but tunes the bandgap and causes more than 700-fold change in the conductivity. Thus, careful defect engineering and selective doping of GNRs with N (and Al) could lead to novel multifunctional materials with exceptional properties. [GRAPHICS] |
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 |
000820987400002 |
Publication Date |
2022-03-15 |
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 |
2352-4928 |
ISBN |
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Additional Links ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
UA library record; WoS full record |
Impact Factor |
|
Times cited |
|
Open Access |
Not_Open_Access |
Notes |
|
Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:189563 |
Serial |
7163 |
Permanent link to this record |
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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 |
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 |
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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 |
000820350600001 |
Publication Date |
2022-06-27 |
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; 2040-3372 |
ISBN |
|
Additional Links ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
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 |
Permanent link to this record |
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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 |
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 |
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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 |
000823038900004 |
Publication Date |
2022-06-16 |
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 |
|
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
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 |
Permanent link to this record |
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Author |
Vanderveken, F.; Tyberkevych, V.; Talmelli, G.; Sorée, B.; Ciubotaru, F.; Adelmann, C. |
Title |
Lumped circuit model for inductive antenna spin-wave transducers |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Scientific reports |
Abbreviated Journal |
Sci Rep-Uk |
Volume |
12 |
Issue |
1 |
Pages |
3796-13 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
We derive a lumped circuit model for inductive antenna spin-wave transducers in the vicinity of a ferromagnetic medium. The model considers the antenna's Ohmic resistance, its inductance, as well as the additional inductance due to the excitation of ferromagnetic resonance or spin waves in the ferromagnetic medium. As an example, the additional inductance is discussed for a wire antenna on top of a ferromagnetic waveguide, a structure that is characteristic for many magnonic devices and experiments. The model is used to assess the scaling properties and the energy efficiency of inductive antennas. Issues related to scaling antenna transducers to the nanoscale and possible solutions are also addressed. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Editor |
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Language |
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Wos |
000826474600050 |
Publication Date |
2022-03-08 |
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 |
|
Edition |
|
ISSN |
2045-2322 |
ISBN |
|
Additional Links ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.6 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
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Approved |
Most recent IF: 4.6 |
Call Number |
UA @ admin @ c:irua:190001 |
Serial |
7180 |
Permanent link to this record |
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Author |
Polanco, C.A.; Pandey, T.; Berlijn, T.; Lindsay, L. |
Title |
Defect-limited thermal conductivity in MoS₂ |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Physical review materials |
Abbreviated Journal |
|
Volume |
4 |
Issue |
1 |
Pages |
014004-14009 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The wide measured range of thermal conductivities (k) for monolayer MoS2 and the corresponding incongruent calculated values in the literature all suggest that extrinsic defect thermal resistance is significant and varied in synthesized samples of this material. Here we present defect-mediated thermal transport calculations of MoS2 using interatomic forces derived from density functional theory combined with Green's function methods to describe phonon-point-defect interactions and a Peierls-Boltzmann formalism for transport. Conductivity calculations for bulk and monolayer MoS2 using different density functional formalisms are compared. Nonperturbative first-principles methods are used to describe defect-mediated spectral functions, scattering rates, and phonon k, particularly from sulfur vacancies (VS), and in the context of the plethora of measured and calculated literature values. We find that k of monolayer MoS2 is sensitive to phonon-VS scattering in the range of experimentally observed densities, and that first-principles k calculations using these densities can explain the range of measured values found in the literature. Furthermore, measured k values for bulk MoS2 are more consistent because VS defects are not as prevalent. |
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Place of Publication |
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Wos |
000619240000001 |
Publication Date |
2020-01-16 |
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 |
2475-9953 |
ISBN |
|
Additional Links ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.4 |
Times cited |
|
Open Access |
|
Notes |
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Approved |
Most recent IF: 3.4; 2020 IF: NA |
Call Number |
UA @ admin @ c:irua:190510 |
Serial |
7757 |
Permanent link to this record |
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Author |
Silva, F.C.O.; Menezes, R.M.; Cabral, L.R.E.; de Souza Silva, C.C. |
Title |
Formation and stability of conformal spirals in confined 2D crystals |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Journal Of Physics-Condensed Matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
32 |
Issue |
50 |
Pages |
505401 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We investigate the ground-state and dynamical properties of nonuniform two-dimensional (2D) clusters of long-range interacting particles. We demonstrate that, when the confining external potential is designed to produce an approximate 1/ r 2 density profile, the particles crystallize into highly ordered structures featuring spiral crystalline lines. Despite the strong inhomogeneity of the observed configurations, most of them are characterized by small density of topological defects, typical of conformal crystals, and the net topological charge induced by the simply-connected geometry of the system is concentrated near the cluster center. These crystals are shown to be robust with respect to thermal fluctuations up to a certain threshold temperature, above which the net charge is progressively redistributed from the center to the rest of the system and the topological order is lost. The crystals are also resilient to the shear stress produced by a small nonuniform azimuthal force field, rotating as a rigid body (RB). For larger forces, topological defects proliferate and the RB rotation gives place to plastic flow. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Language |
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Wos |
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Publication Date |
2020-08-19 |
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 |
0953-8984 |
ISBN |
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Additional Links ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
UA library record |
Impact Factor |
2.7 |
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.7; 2020 IF: 2.649 |
Call Number |
UA @ admin @ c:irua:191093 |
Serial |
7978 |
Permanent link to this record |
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Author |
Menezes, R.M.; Sardella, E.; Cabral, L.R.E.; de Souza Silva, C.C. |
Title |
Self-assembled vortex crystals induced by inhomogeneous magnetic textures |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
|
Volume |
31 |
Issue |
17 |
Pages |
175402 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We investigate the self-assembly of vortices in a type-II superconducting disk subjected to highly nonuniform confining potentials produced by inhomogeneous magnetic textures. Using a series of numerical experiments performed within the Ginzburg–Landau theory, we show that vortices can arrange spontaneously in highly nonuniform, defect-free crystals, reminiscent of conformal lattices, even though the strict conditions for the conformal crystal are not fulfilled. These results contradict continuum-limit theory, which predicts that the order of a nonuniform crystal is unavoidably frustrated by the presence of topological defects. By testing different cooling routes of the superconductor, we observed several different self-assembled configurations, each of which corresponding to one in a set of allowed conformal transformations, which depends on the magnetic and thermal histories of the system. |
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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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Wos |
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Publication Date |
2019-01-30 |
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 |
0953-8984 |
ISBN |
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Additional Links ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
UA library record |
Impact Factor |
|
Times cited |
|
Open Access |
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Notes |
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Approved |
no |
Call Number |
UA @ admin @ c:irua:191094 |
Serial |
8511 |
Permanent link to this record |
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Author |
de Paula Miranda, L. |
Title |
Electronic transport in two dimensional systems with defects |
Type |
Doctoral thesis |
Year |
2022 |
Publication |
|
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
104 p. |
Keywords |
Doctoral thesis; Condensed Matter Theory (CMT) |
Abstract |
The pursuit for the next generation of nanodevices made scientists focus the attention to two dimensional materials. Experimental works of two dimensional materials are hardly free of structural defects, which, in turn, modify drastically the physical properties of its defect-free counterpart. In this work the presence of structural defects is study in two different materials. First, the dependence of the Hall, bend and longitudinal resistances to a perpendicular magnetic field and to vacancy defects in a four-terminal phosphorene single layer Hall bar is investigated. A tight-binding model in combination with the Landauer-Büttiker formalism is used to calculate the energy spectrum, the lead-to-lead transmissions, and the Hall and bend resistances of the system. It is shown that the terminals with zigzag edge orientation are responsible for the absence of quantized plateaus in the Hall resistance and peaks in the longitudinal resistance. A negative bend resistance in the ballistic regime is found due to the presence of high- and low- energy transport modes in the armchair and zigzag terminals, respectively. The system density of states, with single vacancy defects, shows that the presence of in-gap states is proportional to the number of vacancies. Quantized plateaus in the Hall resistance are only formed in a sufficiently clean system. The effects of different kinds of vacancies in the regime where the quantized plateaus are destroyed and a diffusive regime appears in the bend resistance are investigated. Next, we explore effects due to point defect clustering on the electronic and transport properties of bilayer graphene nanoribbons, for AA and AB stacking and zigzag and armchair boundaries, by means of the tight-binding approach and scattering matrix formalism. Evidence of vacancy concentration signatures exhibiting a maximum amplitude and an universality regardless of the system size, stacking and boundary types, in the density of states around the zero-energy level are observed. Our results are explained via the coalescence analysis of the strong sizeable vacancy clustering effect in the system and the breaking of inversion symmetry at high vacancy densities, demonstrating a similar density of states for two equivalent degrees of concentration disorder, below and above the maximum value. |
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Wos |
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Publication Date |
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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 ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
UA library record |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
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Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:191340 |
Serial |
7151 |
Permanent link to this record |
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Author |
Berdiyorov, G.R.; Peeters, F.M.; Hamoudi, H. |
Title |
Effect of halogenation on the electronic transport properties of aromatic and alkanethiolate molecules |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Physica. E: Low-dimensional systems and nanostructures |
Abbreviated Journal |
Physica E |
Volume |
144 |
Issue |
|
Pages |
115428-6 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
Quantum transport calculations are conducted using nonequilibrium Green's functional formalism to study the effect of halogenation on the electronic transport properties of aromatic S-(C6H5)(2)X and alkanethiolate S-(CH2)(11)X molecules (with X = H, F, Cl, Br, or I) sandwiched between gold electrodes. In terms of conductance, both molecules show the same dependence on the halogen terminal groups despite their different electronic nature. For example, fluorination results in a reduction of the current by almost an order of magnitude, whereas iodine substitution leads to larger current as compared to the reference system (i.e. hydrogen termination). Regarding the asymmetry in the current-voltage characteristics, halogenation reduces the rectification level for the aromatic molecule with the smallest asymmetry for iodine termination. However, in the case of alkanethiolate molecule, halogen substitution increases the current rectification except for fluorination. A physical explanation of these results is obtained from the analysis of the behavior of the density of states, transmission spectra and transmission eigenstates. These findings are of practical importance in exploring the potential of halogenation for creating functional molecular self-assemblies on metallic substrates. |
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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 |
000857051700007 |
Publication Date |
2022-07-20 |
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 |
1386-9477 |
ISBN |
|
Additional Links ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.3 |
Times cited |
1 |
Open Access |
Not_Open_Access |
Notes |
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Approved |
Most recent IF: 3.3 |
Call Number |
UA @ admin @ c:irua:191500 |
Serial |
7148 |
Permanent link to this record |
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Author |
Reichhardt, C.; Reichhardt, C.J.O.; Milošević, M.V. |
Title |
Statics and dynamics of skyrmions interacting with disorder and nanostructures |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Reviews of modern physics |
Abbreviated Journal |
Rev Mod Phys |
Volume |
94 |
Issue |
3 |
Pages |
035005-35061 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Magnetic skyrmions are topologically stable nanoscale particlelike objects that were discovered in 2009. Since that time, intense research interest in the field has led to the identification of numerous compounds that support skyrmions over a range of conditions spanning from cryogenic to room temperatures. Skyrmions can be set into motion under various types of driving, and the combination of their size, stability, and dynamics makes them ideal candidates for numerous applications. At the same time, skyrmions represent a new class of system in which the energy scales of the skyrmion-skyrmion interactions, sample disorder, temperature, and drive can compete. A growing body of work indicates that the static and dynamic states of skyrmions can be influenced strongly by pinning or disorder in the sample; thus, an understanding of such effects is essential for the eventual use of skyrmions in applications. The current state of knowledge regarding individual skyrmions and skyrmion assemblies interacting with quenched disorder or pinning is reviewed. The microscopic mechanisms for skyrmion pinning, including the repulsive and attractive interactions that can arise from impurities, grain boundaries, or nanostructures, are outlined. This is followed by descriptions of depinning phenomena, sliding states over disorder, the effect of pinning on the skyrmion Hall angle, the competition between thermal and pinning effects, the control of skyrmion motion using ordered potential landscapes such as one-or two-dimensional periodic asymmetric substrates, the creation of skyrmion diodes, and skyrmion ratchet effects. Highlighted are the distinctions arising from internal modes and the strong gyrotropic or Magnus forces that cause the dynamical states of skyrmions to differ from those of other systems with pinning, such as vortices in type-II superconductors, charge density waves, or colloidal particles. Throughout this review future directions and open questions related to the and in are also discussed. |
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Corporate Author |
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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 |
000861559900001 |
Publication Date |
2022-09-20 |
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 |
0034-6861; 1539-0756 |
ISBN |
|
Additional Links ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
44.1 |
Times cited |
12 |
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 44.1 |
Call Number |
UA @ admin @ c:irua:191507 |
Serial |
7339 |
Permanent link to this record |
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Author |
Mirzakhani, M.; Myoung, N.; Peeters, F.M.; Park, H.C. |
Title |
Electronic Mach-Zehnder interference in a bipolar hybrid monolayer-bilayer graphene junction |
Type |
A1 Journal article |
Year |
2023 |
Publication |
Carbon |
Abbreviated Journal |
|
Volume |
201 |
Issue |
|
Pages |
734-744 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Graphene matter in a strong magnetic field, realizing one-dimensional quantum Hall channels, provides a unique platform for studying electron interference. Here, using the Landauer-Buttiker formalism along with the tightbinding model, we investigate the quantum Hall (QH) effects in unipolar and bipolar monolayer-bilayer graphene (MLG-BLG) junctions. We find that a Hall bar made of an armchair MLG-BLG junction in the bipolar regime results in valley-polarized edgechannel interferences and can operate a fully tunable Mach-Zehnder (MZ) interferometer device. Investigation of the bar-width and magnetic-field dependence of the conductance oscillations shows that the MZ interference in such structures can be drastically affected by the type of (zigzag) edge termination of the second layer in the BLG region [composed of vertical dimer or non-dimer atoms]. Our findings reveal that both interfaces exhibit a double set of Aharonov-Bohm interferences, with the one between two oppositely valley-polarized edge channels dominating and causing a large amplitude conductance oscillation ranging from 0 to 2e2/h. We explain and analyze our findings by analytically solving the Dirac-Weyl equation for a gated semi-infinite MLG-BLG junction. |
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Place of Publication |
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Language |
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Wos |
000868911500004 |
Publication Date |
2022-09-28 |
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 ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
10.9 |
Times cited |
3 |
Open Access |
Not_Open_Access |
Notes |
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Approved |
Most recent IF: 10.9; 2023 IF: 6.337 |
Call Number |
UA @ admin @ c:irua:191516 |
Serial |
7302 |
Permanent link to this record |
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Author |
Jiang, J.; Milošević, M.V.; Wang, Y.-L.; Xiao, Z.-L.; Peeters, F.M.; Chen, Q.-H. |
Title |
Field-free superconducting diode in a magnetically nanostructured superconductor |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Physical review applied |
Abbreviated Journal |
Phys Rev Appl |
Volume |
18 |
Issue |
3 |
Pages |
034064-34069 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
A strong superconducting diode effect (SDE) is revealed in a thin superconducting film periodically nanostructured with magnetic dots. The SDE is caused by the current-activated dissipation mitigated by vortex-antivortex pairs (VAPs), which periodically nucleate under the dots, move and annihilate in the superconductor-eventually driving the system to the high-resistive state. Inversing the polarity of the applied current destimulates the nucleation of VAPs, the system remains superconducting up to far larger currents, leading to the pronounced diodic response. Our dissipative Ginzburg-Landau simulations detail the involved processes, and provide reliable geometric and parametric ranges for the experimental realiza-tion of such a nonvolatile superconducting diode, which operates in the absence of any applied magnetic field while being fluxonic by design. |
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Place of Publication |
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Wos |
000870234200001 |
Publication Date |
2022-09-23 |
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 |
2331-7019 |
ISBN |
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Additional Links ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.6 |
Times cited |
9 |
Open Access |
OpenAccess |
Notes |
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Approved |
Most recent IF: 4.6 |
Call Number |
UA @ admin @ c:irua:191539 |
Serial |
7307 |
Permanent link to this record |
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Author |
Yu, Y.; Xie, X.; Liu, X.; Li, J.; Peeters, F.M.; Li, L. |
Title |
Two-dimensional semimetal states in transition metal trichlorides : a first-principles study |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
121 |
Issue |
11 |
Pages |
112405-112407 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The two-dimensional (2D) transition metal trihalide (TMX3, X = Cl, Br, I) family has attracted considerable attention in recent years due to the realization of CrCl3, CrBr3, and CrI3 monolayers. Up to now, the main focus of the theoretically predicted TMX3 monolayers has been on the Chern insulator states, which can realize the quantum anomalous Hall effect. Here, using first-principles calculations, we theoretically demonstrate that the stable OsCl3 monolayer has a ferromagnetic ground state and a spin-polarized Dirac point without spin-orbit coupling (SOC), which disappears in the band structure of a Janus OsBr1.5Cl1.5 monolayer. We find that OsCl3 exhibits in-plane magnetization when SOC is included. By manipulating the magnetization direction along the C-2 symmetry axis of the OsCl3 structure, a gapless half-Dirac semimetal state with SOC can be achieved, which is different from the gapped Chern insulator state. Both semimetal states of OsCl3 monolayer without and with SOC exhibit a linear half-Dirac point (twofold degenerate) with high Fermi velocities. The achievement of the 2D semimetal state with SOC is expected to be found in other TMX3 monolayers, and we confirm it in a TiCl3 monolayer. This provides a different perspective to study the band structure with SOC of the 2D TMX3 family. |
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Place of Publication |
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Editor |
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Language |
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Wos |
000863219400003 |
Publication Date |
2022-09-15 |
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 |
0003-6951; 1077-3118 |
ISBN |
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Additional Links ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
UA library record; WoS full record |
Impact Factor |
4 |
Times cited |
4 |
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 4 |
Call Number |
UA @ admin @ c:irua:191541 |
Serial |
7223 |
Permanent link to this record |
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Author |
Deylgat, E.; Chen, E.; Fischetti, M.V.; Sorée, B.; Vandenberghe, W.G. |
Title |
Image-force barrier lowering in top- and side-contacted two-dimensional materials |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Solid state electronics |
Abbreviated Journal |
Solid State Electron |
Volume |
198 |
Issue |
|
Pages |
108458-4 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We compare the image-force barrier lowering (IFBL) and calculate the resulting contact resistance for four different metal-dielectric-two-dimensional (2D) material configurations. We analyze edge contacts in three different geometries (a homogeneous dielectric throughout, including the 2D layer; a homogeneous dielectric surrounding the 2D layer, both ungated and back gated) and also a top-contact assuming a homogeneous dielectric. The image potential energy of each configuration is determined and added to the Schottky energy barrier which is calculated assuming a textbook Schottky potential. For each configuration, the contact resistivity is calculated using the WKB approximation and the effective mass approximation using either SiO2 or HfO2 as the surrounding dielectric. We obtain the lowest contact resistance of 1 k Omega mu m by n-type doping an edge contacted transition metal-dichalcogenide (TMD) monolayer, sandwiched between SiO2 dielectric, with similar to 1012 cm-2 donor atoms. When this optimal configuration is used, the contact resistance is lowered by a factor of 50 compared to the situation when the IFBL is not considered. |
Address |
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Corporate Author |
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Place of Publication |
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Editor |
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Language |
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Wos |
000876289800003 |
Publication Date |
2022-09-22 |
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 |
0038-1101 |
ISBN |
|
Additional Links ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
UA library record; WoS full record |
Impact Factor |
1.7 |
Times cited |
|
Open Access |
Not_Open_Access |
Notes |
|
Approved |
Most recent IF: 1.7 |
Call Number |
UA @ admin @ c:irua:191556 |
Serial |
7312 |
Permanent link to this record |
|
|
|
Author |
Cai, J.; Griffin, E.; Guarochico-Moreira, V.H.; Barry, D.; Xin, B.; Yagmurcukardes, M.; Zhang, S.; Geim, A.K.; Peeters, F.M.; Lozada-Hidalgo, M. |
Title |
Wien effect in interfacial water dissociation through proton-permeable graphene electrodes |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
13 |
Issue |
1 |
Pages |
5776-5777 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
Strong electric fields can accelerate molecular dissociation reactions. The phenomenon known as the Wien effect was previously observed using high-voltage electrolysis cells that produced fields of about 10(7) V m(-1), sufficient to accelerate the dissociation of weakly bound molecules (e.g., organics and weak electrolytes). The observation of the Wien effect for the common case of water dissociation (H2O reversible arrow H+ + OH-) has remained elusive. Here we study the dissociation of interfacial water adjacent to proton-permeable graphene electrodes and observe strong acceleration of the reaction in fields reaching above 10(8) V m(-1). The use of graphene electrodes allows measuring the proton currents arising exclusively from the dissociation of interfacial water, while the electric field driving the reaction is monitored through the carrier density induced in graphene by the same field. The observed exponential increase in proton currents is in quantitative agreement with Onsager's theory. Our results also demonstrate that graphene electrodes can be valuable for the investigation of various interfacial phenomena involving proton transport. |
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 |
000862552600012 |
Publication Date |
2022-10-01 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
16.6 |
Times cited |
14 |
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 16.6 |
Call Number |
UA @ admin @ c:irua:191575 |
Serial |
7228 |
Permanent link to this record |
|
|
|
Author |
Wang, F.; Wang, C.; Chaves, A.; Song, C.; Zhang, G.; Huang, S.; Lei, Y.; Xing, Q.; Mu, L.; Xie, Y.; Yan, H. |
Title |
Prediction of hyperbolic exciton-polaritons in monolayer black phosphorus |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Nature Communications |
Abbreviated Journal |
Nat Commun |
Volume |
12 |
Issue |
1 |
Pages |
5628 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
Hyperbolic polaritons exhibit large photonic density of states and can be collimated in certain propagation directions. The majority of hyperbolic polaritons are sustained in man-made metamaterials. However, natural-occurring hyperbolic materials also exist. Particularly, natural in-plane hyperbolic polaritons in layered materials have been demonstrated in MoO3 and WTe2, which are based on phonon and plasmon resonances respectively. Here, by determining the anisotropic optical conductivity (dielectric function) through optical spectroscopy, we predict that monolayer black phosphorus naturally hosts hyperbolic exciton-polaritons due to the pronounced in-plane anisotropy and strong exciton resonances. We simultaneously observe a strong and sharp ground state exciton peak and weaker excited states in high quality monolayer samples in the reflection spectrum, which enables us to determine the exciton binding energy of similar to 452 meV. Our work provides another appealing platform for the in-plane natural hyperbolic polaritons, which is based on excitons rather than phonons or plasmons. |
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 |
000698984500003 |
Publication Date |
2021-10-12 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2041-1723 |
ISBN |
|
Additional Links ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
|
Open Access |
Not_Open_Access |
Notes |
|
Approved |
Most recent IF: 12.124 |
Call Number |
UA @ admin @ c:irua:191688 |
Serial |
8404 |
Permanent link to this record |
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|
|
Author |
Miranda, L.P.; da Costa, D.R.; Peeters, F.M.; Costa Filho, R.N. |
Title |
Vacancy clustering effect on the electronic and transport properties of bilayer graphene nanoribbons |
Type |
A1 Journal article |
Year |
2023 |
Publication |
Nanotechnology |
Abbreviated Journal |
|
Volume |
34 |
Issue |
5 |
Pages |
055706-55710 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
Experimental realizations of two-dimensional materials are hardly free of structural defects such as e.g. vacancies, which, in turn, modify drastically its pristine physical defect-free properties. In this work, we explore effects due to point defect clustering on the electronic and transport properties of bilayer graphene nanoribbons, for AA and AB stacking and zigzag and armchair boundaries, by means of the tight-binding approach and scattering matrix formalism. Evident vacancy concentration signatures exhibiting a maximum amplitude and an universality regardless of the system size, stacking and boundary types, in the density of states around the zero-energy level are observed. Our results are explained via the coalescence analysis of the strong sizeable vacancy clustering effect in the system and the breaking of the inversion symmetry at high vacancy densities, demonstrating a similar density of states for two equivalent degrees of concentration disorder, below and above the maximum value. |
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 |
000886630000001 |
Publication Date |
2022-11-02 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0957-4484 |
ISBN |
|
Additional Links ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.5 |
Times cited |
1 |
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 3.5; 2023 IF: 3.44 |
Call Number |
UA @ admin @ c:irua:192030 |
Serial |
7350 |
Permanent link to this record |
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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 |
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 |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
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Editor |
|
Language |
|
Wos |
000880827900001 |
Publication Date |
2022-10-22 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984 |
ISBN |
|
Additional Links ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
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 |
Permanent link to this record |
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|
|
Author |
Pandey, T.; Du, M.-H.; Parker, D.S.; Lindsay, L. |
Title |
Origin of ultralow phonon transport and strong anharmonicity in lead-free halide perovskites |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Materials Today Physics |
Abbreviated Journal |
|
Volume |
28 |
Issue |
|
Pages |
100881-10 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
All-inorganic lead-free halide double perovskites offer a promising avenue toward non-toxic, stable optoelec-tronic materials, properties that are missing in their prominent lead-containing counterparts. Their large ther-mopowers and high carrier mobilities also make them promising for thermoelectric applications. Here, we present a first-principles study of the lattice vibrations and thermal transport behaviors of Cs2SnI6 and gamma-CsSnI3, two prototypical compounds in this materials class. We show that conventional static zero temperature density functional theory (DFT) calculations severely underestimate the lattice thermal conductivities (kappa l) of these compounds, indicating the importance of dynamical effects. By calculating anharmonic renormalized phonon dispersions, we show that some optic phonons significantly harden with increasing temperature (T), which reduces the scattering of heat carrying phonons and enhances calculated kappa l values when compared with standard zero temperature DFT. Furthermore, we demonstrate that coherence contributions to kappa l, arising from wave like phonon tunneling, are important in both compounds. Overall, calculated kappa l with temperature-dependent inter-atomic force constants, built from particle and coherence contributions, are in good agreement with available measured data, for both magnitude and temperature dependence. Large anharmonicity combined with low phonon group velocities yield ultralow kappa l values, with room temperature values of 0.26 W/m-K and 0.72 W/m-K predicted for Cs2SnI6 and gamma-CsSnI3, respectively. We further show that the lattice dynamics of these compounds are highly anharmonic, largely mediated by rotation of the SnI6 octahedra and localized modes originating from Cs rattling motion. These thermal characteristics combined with their previously computed excellent electronic properties make these perovskites promising candidates for optoelectronic and room temperature thermoelectric 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 |
|
Editor |
|
Language |
|
Wos |
000876484300002 |
Publication Date |
2022-10-10 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2542-5293 |
ISBN |
|
Additional Links ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
11.5 |
Times cited |
|
Open Access |
Not_Open_Access |
Notes |
|
Approved |
Most recent IF: 11.5 |
Call Number |
UA @ admin @ c:irua:192139 |
Serial |
7329 |
Permanent link to this record |
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|
|
Author |
Gobato, Y.G.; de Brito, C.S.; Chaves, A.; Prosnikov, M.A.; Wozniak, T.; Guo, S.; Barcelos, I.D.; Milošević, M.V.; Withers, F.; Christianen, P.C.M. |
Title |
Distinctive g-factor of Moire-confined excitons in van der Waals heterostructures |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Nano letters |
Abbreviated Journal |
Nano Lett |
Volume |
22 |
Issue |
21 |
Pages |
8641-8641 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
We investigated the valley Zeeman splitting of excitonic peaks in the microphotoluminescence (mu PL) spectra of high-quality hBN/WS2/MoSe2/hBN heterostructures under perpendicular magnetic fields up to 20 T. We identify two neutral exciton peaks in the mu PL spectra; the lower-energy peak exhibits a reduced g-factor relative to that of the higher energy peak and much lower than the recently reported values for interlayer excitons in other van der Waals (vdW) heterostructures. We provide evidence that such a discernible g-factor stems from the spatial confinement of the exciton in the potential landscape created by the moire pattern due to lattice mismatch or interlayer twist in heterobilayers. This renders magneto-mu PL an important tool to reach a deeper understanding of the effect of moire patterns on excitonic confinement in vdW heterostructures. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000877287800001 |
Publication Date |
2022-10-24 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1530-6984 |
ISBN |
|
Additional Links ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
10.8 |
Times cited |
3 |
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 10.8 |
Call Number |
UA @ admin @ c:irua:192166 |
Serial |
7298 |
Permanent link to this record |
|
|
|
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 |
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 |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
|
Editor |
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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 ![sorted by Additional Links field, ascending order (up)](img/sort_asc.gif) |
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 |
Permanent link to this record |