| Records |
| Author |
Mobaraki, A.; Sevik, C.; Yapicioglu, H.; Cakir, D.; Gulseren, O. |
| Title |
Temperature-dependent phonon spectrum of transition metal dichalcogenides calculated from the spectral energy density: Lattice thermal conductivity as an application |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
Physical review B |
Abbreviated Journal |
|
| Volume |
100 |
Issue |
3 |
Pages |
035402 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Predicting the mechanical and thermal properties of quasi-two-dimensional (2D) transition metal dichalco-genides (TMDs) is an essential task necessary for their implementation in device applications. Although rigorous density-functional-theory-based calculations are able to predict mechanical and electronic properties, mostly they are limited to zero temperature. Classical molecular dynamics facilitates the investigation of temperature-dependent properties, but its performance highly depends on the potential used for defining interactions between the atoms. In this study, we calculated temperature-dependent phonon properties of single-layer TMDs, namely, MoS2, MoSe2, WS2, and WSe2, by utilizing Stillinger-Weber-type potentials with optimized sets of parameters with respect to the first-principles results. The phonon lifetimes and contribution of each phonon mode in thermal conductivities in these monolayer crystals are systematically investigated by means of the spectralenergy-density method based on molecular dynamics simulations. The obtained results from this approach are in good agreement with previously available results from the Green-Kubo method. Moreover, detailed analysis of lattice thermal conductivity, including temperature-dependent mode decomposition through the entire Brillouin zone, shed more light on the thermal properties of these 2D crystals. The LA and TA acoustic branches contribute most to the lattice thermal conductivity, while ZA mode contribution is less because of the quadratic dispersion around the Brillouin zone center, particularly in MoSe2 due to the phonon anharmonicity, evident from the redshift, especially in optical modes, by increasing temperature. For all the considered 2D crystals, the phonon lifetime values are compelled by transition metal atoms, whereas the group velocity spectrum is dictated by chalcogen atoms. Overall, the lattice thermal conductivity is linearly proportional with inverse temperature. |
| Address |
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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 |
000473536400003 |
Publication Date |
2019-07-02 |
| 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 |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
no |
| Call Number |
UA @ admin @ c:irua:193764 |
Serial |
8645 |
| Permanent link to this record |
| |
|
| |
| Author |
Vermeulen, B.B.; Monteiro, M.G.; Giuliano, D.; Sorée, B.; Couet, S.; Temst, K.; Nguyen, V.D. |
| Title |
Magnetization-switching dynamics driven by chiral coupling |
Type |
A1 Journal article |
| Year |
2024 |
Publication |
Physical review applied |
Abbreviated Journal |
|
| Volume |
21 |
Issue |
2 |
Pages |
024050-11 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The Dzyaloshinskii-Moriya interaction (DMI) is known to play a central role in stabilizing chiral spin textures such as skyrmions and domain walls (DWs). Electrical manipulation of DW and skyrmion motion offers possibilities for next-generation, scalable and energy-efficient spintronic devices. However, achieving the full potential of these nanoscale devices requires overcoming several challenges, including reliable electrical write and read techniques for these magnetic objects, and addressing pinning and Joule-heating concerns. Here, through micromagnetic simulations and analytical modeling, we show that DMI can directly induce magnetization switching of a nanomagnet with perpendicular magnetic anisotropy (PMA). We find that the switching is driven by the interplay between the DMI-induced magnetic frustration and the PMA. By introducing magnetic tunnel junctions to electrically access and control the magnetization direction of the PMA nanomagnet, we first show the potential of this concept to enable high-density fieldfree spin-orbit torque magnetic random-access memory. Ultimately, we demonstrate that it offers a way of transferring and processing spin information for logic operation without relying on current-driven DW or skyrmion motion. |
| 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 |
001187487900001 |
Publication Date |
2024-02-26 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
no |
| Call Number |
UA @ admin @ c:irua:205518 |
Serial |
9157 |
| Permanent link to this record |
| |
|
| |
| Author |
Akande, S.O.; Samanta, B.; Sevik, C.; Cakir, D. |
| Title |
First-principles investigation of mechanical and thermal properties of M Al B (M = Mo, W), Cr₂ AlB₂, and Ti₂ In B₂ |
Type |
A1 Journal article |
| Year |
2023 |
Publication |
Physical review applied |
Abbreviated Journal |
|
| Volume |
20 |
Issue |
4 |
Pages |
044064-17 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The atomically laminated layered ternary transition-metal borides (the MAB phases) have demonstrated outstanding properties and have been applied in various fields. Understanding their thermal and mechanical properties is critical to determining their applicability in various fields such as high-temperature applications. To achieve this, we conducted first-principles calculations based on density-functional theory and the quasiharmonic approximation to determine the thermal expansion coefficients, Gruneisen parameters, bulk moduli, hardness, thermal conductivity, electron-phonon coupling parameters, and the structural and vibrational properties of MoAlB, WAlB, Cr2AlB2, and Ti2InB2. We found varying degrees of anisotropy in the thermal expansion and mechanical properties in spite of similarities in their crystal structures. MoAlB has a mild degree of anisotropy in its thermal expansion coefficient (TEC), while Cr2AlB2 and WAlB display the highest level of TEC anisotropy. We assessed various empirical models to calculate hardness and thermal conductivity, and correlated the calculated values with the material properties such as elastic moduli, Gruneisen parameter, Debye temperature, and type of bonding. Owing to their higher Gruneisen parameters, implying a greater degree of anharmonicity in lattice vibrations and lower phonon group velocities, MoAlB and WAlB have significantly lower lattice thermal conductivity values than those of Cr2AlB2 and Ti2InB2. The hardness and lattice thermal conductivity of MAB phases can be predicted with high accuracy if one utilizes an appropriate model. |
| 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 |
001106456600003 |
Publication Date |
2023-10-25 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| Impact Factor |
4.6 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 4.6; 2023 IF: 4.808 |
| Call Number |
UA @ admin @ c:irua:202078 |
Serial |
9037 |
| Permanent link to this record |
| |
|
| |
| Author |
Foltyn, M.; Norowski, K.; Wyszynski, M.J.; De Arruda, A.S.; Milošević, M.V.; Zgirski, M. |
| Title |
Probing confined vortices with a superconducting nanobridge |
Type |
A1 Journal article |
| Year |
2023 |
Publication |
Physical review applied |
Abbreviated Journal |
|
| Volume |
19 |
Issue |
4 |
Pages |
044073-12 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We realize a superconducting nanodevice in which vortex traps in the form of an aluminum square are integrated with a Dayem nanobridge. We perform field cooling of the traps arriving to different vortex configurations, dependent on the applied magnetic field, to demonstrate that the switching current of the bridge is highly sensitive to the presence and location of vortices in the trap. Our measurements exhibit unprecedented precision and ability to detect the first and successive vortex entries into all fabricated traps, from few hundred nm to 2 mu m in size. The experimental results are corroborated by Ginzburg-Landau simulations, which reveal the subtle yet crucial changes in the density of the superconducting condensate in the vicinity of the bridge with every additional vortex entry and relocation inside the trap. An ease of integration and simplicity make our design a convenient platform for studying dynamics of vortices in strongly confining geometries, involving a promise to manipulate vortex states electronically with simultaneous in situ control and monitoring. |
| 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 |
000980861100007 |
Publication Date |
2023-04-24 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| Impact Factor |
4.6 |
Times cited |
|
Open Access |
Not_Open_Access |
| Notes |
|
Approved |
Most recent IF: 4.6; 2023 IF: 4.808 |
| Call Number |
UA @ admin @ c:irua:197356 |
Serial |
8918 |
| Permanent link to this record |
| |
|
| |
| Author |
Tiwari, S.; Van de Put, M.L.; Temst, K.; Vandenberghe, W.G.; Sorée, B. |
| Title |
Atomistic modeling of spin and electron dynamics in two-dimensional magnets switched by two-dimensional topological insulators |
Type |
A1 Journal article |
| Year |
2023 |
Publication |
Physical review applied |
Abbreviated Journal |
|
| Volume |
19 |
Issue |
1 |
Pages |
014040-14049 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
To design fast memory devices, we need material combinations that can facilitate fast read and write operations. We present a heterostructure comprising a two-dimensional (2D) magnet and a 2D topological insulator (TI) as a viable option for designing fast memory devices. We theoretically model the spin-charge dynamics between 2D magnets and 2D TIs. Using the adiabatic approximation, we combine the nonequi-librium Green's function method for spin-dependent electron transport and a time-quantified Monte Carlo method for simulating magnetization dynamics. We show that it is possible to switch a magnetic domain of a ferromagnet using the spin torque from spin-polarized edge states of a 2D TI. We show further that the switching of 2D magnets by TIs is strongly dependent on the interface exchange (Jint), and an opti-mal interface exchange, is required for efficient switching. Finally, we compare experimentally grown Cr compounds and show that Cr compounds with higher anisotropy (such as CrI3) result in a lower switching speed but a more stable magnetic order. |
| 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 |
000920227500002 |
Publication Date |
2023-01-12 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.6 |
Times cited |
|
Open Access |
Not_Open_Access |
| Notes |
|
Approved |
Most recent IF: 4.6; 2023 IF: 4.808 |
| Call Number |
UA @ admin @ c:irua:194312 |
Serial |
7283 |
| Permanent link to this record |
| |
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| |
| Author |
Sethu, K.K.V.; Ghosh, S.; Couet, S.; Swerts, J.; Sorée, B.; De Boeck, J.; Kar, G.S.; Garello, K. |
| Title |
Optimization of tungsten beta-phase window for spin-orbit-torque magnetic random-access memory |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Physical Review Applied |
Abbreviated Journal |
Phys Rev Appl |
| Volume |
16 |
Issue |
6 |
Pages |
064009 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Switching induced by spin-orbit torque (SOT) is being vigorously explored, as it allows the control of magnetization using an in-plane current, which enables a three-terminal magnetic-tunnel-junction geometry with isolated read and write paths. This significantly improves the device endurance and the read stability, and allows reliable subnanosecond switching. Tungsten in the beta phase, beta-W, has the largest reported antidamping SOT charge-to-spin conversion ratio (theta(AD) approximate to -60%) for heavy metals. However, beta-W has a limitation when one is aiming for reliable technology integration: the beta phase is limited to a thickness of a few nanometers and enters the alpha phase above 4 nm in our samples when industry-relevant deposition tools are used. Here, we report our approach to extending the range of beta-W, while simultaneously improving the SOT efficiency by introducing N and O doping of W. Resistivity and XRD measurements confirm the extension of the beta phase from 4 nm to more than 10 nm, and transport characterization shows an effective SOT efficiency larger than -44.4% (reaching approximately -60% for the bulk contribution). In addition, we demonstrate the possibility of controlling and enhancing the perpendicular magnetic anisotropy of a storage layer (Co-Fe-B). Further, we integrate the optimized W(O, N) into SOT magnetic random-access memory (SOT-MRAM) devices and project that, for the same thickness of SOT material, the switching current decreases by 25% in optimized W(O, N) compared with our standard W. Our results open the path to using and further optimizing W for integration of SOT-MRAM technology. |
| 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 |
000729005800002 |
Publication Date |
2021-12-03 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.808 |
Times cited |
|
Open Access |
Not_Open_Access |
| Notes |
|
Approved |
Most recent IF: 4.808 |
| Call Number |
UA @ admin @ c:irua:184832 |
Serial |
7007 |
| Permanent link to this record |
| |
|
| |
| Author |
Tao, Z.H.; Dong, H.M.; Milošević, M.V.; Peeters, F.M.; Van Duppen, B. |
| Title |
Tailoring dirac plasmons via anisotropic dielectric environment by design |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Physical Review Applied |
Abbreviated Journal |
Phys Rev Appl |
| Volume |
16 |
Issue |
5 |
Pages |
054030 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Dirac plasmons in a two-dimensional (2D) crystal are strongly affected by the dielectric properties of the environment, due to interaction of their electric field lines with the surrounding medium. Using graphene as a 2D reservoir of free carriers, one can engineer a material configuration that provides an anisotropic environment to the plasmons. In this work, we discuss the physical properties of Dirac plasmons in graphene surrounded by an arbitrary anisotropic dielectric and exemplify how h-BN-based heterostructures can be designed to bear the required anisotropic characteristics. We calculate how dielec-tric anisotropy impacts the spatial propagation of the plasmons and find that an anisotropy-induced plasmon mode emerges, together with a damping pathway, that stem from the out-of-plane off-diagonal elements in the dielectric tensor. Furthermore, we find that one can create hyperbolic plasmons by inher-iting the dielectric hyperbolicity of the designed material environment. Strong control over plasmon propagation patterns can be realized in a similar manner. Finally, we show that in this way one can also control the polarization of the light-matter excitations that constitute the plasmon. Taken together, our results promote the design of the dielectric environment as an effective path to tailor the plasmonic response of graphene on the nanoscopic level. |
| 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 |
000720372500002 |
Publication Date |
2021-11-15 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.808 |
Times cited |
1 |
Open Access |
Not_Open_Access |
| Notes |
|
Approved |
Most recent IF: 4.808 |
| Call Number |
UA @ admin @ c:irua:184063 |
Serial |
7028 |
| Permanent link to this record |
| |
|
| |
| Author |
Yin, L.; Juneja, R.; Lindsay, L.; Pandey, T.; Parker, D.S. |
| Title |
Semihard iron-based permanent-magnet materials |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Physical Review Applied |
Abbreviated Journal |
Phys Rev Appl |
| Volume |
15 |
Issue |
2 |
Pages |
024012 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Permanent magnets generally require a favorable, but difficult-to-achieve combination of high magnetization, Curie point, and magnetic anisotropy. Thus there have been few, if any, viable permanent magnets developed since the 1982 discovery of Nd2Fe14B [M. Sagawa, S. Fujimura, H. Yamamoto, Y. Matsuura, and S. Hirosawa, J. Appl. Phys. 57, 4094 (1985)]. Here we point out, both by direct first-principles calculations on the iron carbides and silicides Fe5C2, Fe5SiC, and Fe7C3 as well as a discussion of recent experimental findings, that there are numerous rare-earth-free iron-rich potential permanent-magnet materials with sufficient intrinsic magnetic properties to reasonably achieve room-temperature energy products of 20-25 MG Oe. This is substantially better than the performance of the best available rare-earth-free magnets based on ferrite, as well as shape-anisotropy-employing alnico. These magnets could plausibly fill, at low cost, the present performance “gap” [J. M. D. Coey, Scr. Mater. 67, 524 (2012)] between the best rare-earth-free magnets and rare-earth magnets such as Nd2Fe14B and Sm-Co. |
| 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 |
000614707800002 |
Publication Date |
2021-02-05 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.808 |
Times cited |
|
Open Access |
Not_Open_Access |
| Notes |
|
Approved |
Most recent IF: 4.808 |
| Call Number |
UA @ admin @ c:irua:176624 |
Serial |
6734 |
| Permanent link to this record |
| |
|
| |
| Author |
Karaaslan, Y.; Yapicioglu, H.; Sevik, C. |
| Title |
Assessment of Thermal Transport Properties of Group-III Nitrides: A Classical Molecular Dynamics Study with Transferable Tersoff-Type Interatomic Potentials |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Physical Review Applied |
Abbreviated Journal |
Phys Rev Appl |
| Volume |
13 |
Issue |
3 |
Pages |
034027 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
In this study, by means of classical molecular dynamics simulations, we investigate the thermal-transport properties of hexagonal single-layer, zinc-blend, and wurtzite phases of BN, AlN, and GaN crystals, which are very promising for the application and design of high-quality electronic devices. With this in mind, we generate fully transferable Tersoff-type empirical interatomic potential parameter sets by utilizing an optimization procedure based on particle-swarm optimization. The predicted thermal properties as well as the structural, mechanical, and vibrational properties of all materials are in very good agreement with existing experimental and first-principles data. The impact of isotopes on thermal transport is also investigated and between approximately 10 and 50% reduction in phonon thermal transport with random isotope distribution is observed in BN and GaN crystals. Our investigation distinctly shows that the generated parameter sets are fully transferable and very useful in exploring the thermal properties of systems containing these nitrides. |
| 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 |
000518820200003 |
Publication Date |
2020-03-10 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.6 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 4.6; 2020 IF: 4.808 |
| Call Number |
UA @ admin @ c:irua:193766 |
Serial |
7508 |
| Permanent link to this record |
| |
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| |
| Author |
Sevik, C.; Çakir, D. |
| Title |
Tailoring Storage Capacity and Ion Kinetics in Ti2CO2/Graphene Heterostructures by Functionalization of Graphene |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
Physical review applied |
Abbreviated Journal |
|
| Volume |
12 |
Issue |
1 |
Pages |
014001 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Using first-principles calculations, we evaluate the electrochemical performance of heterostructures made up of Ti2CO2 and chemically modified graphene for Li batteries. We find that heteroatom doping and molecule intercalation have a significant impact on the storage capacity and Li migration barrier energies. While N and S doping do not improve the storage capacity, B doping together with molecule interaction make it possible to intercalate two layers of Li, which stick separately to the surface of Ti2CO2 and B-doped graphene. The calculated diffusion-barrier energies (E-diff), which are between 0.3 and 0.4 eV depending on Li concentration, are quite promising for fast charge and discharge rates. Besides, the predicted E-diff as much as 2 eV for the diffusion of the Li atom from the Ti2CO2 surface to the B-doped graphene surface significantly suppresses the interlayer Li migration, which diminishes the charge and discharge rates. The calculated volume and lattice parameter changes indicate that Ti2CO2/graphene hybrid structures exhibit cyclic stability against Li loading and unloading. Consequently, first-principles calculations we perform evidently highlight the favorable effect of molecular intercalation on the capacity improvement of ion batteries. |
| 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 |
000473312000001 |
Publication Date |
2019-07-01 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
no |
| Call Number |
UA @ admin @ c:irua:193755 |
Serial |
8640 |
| Permanent link to this record |
| |
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| |
| Author |
Barbier, M.; Vasilopoulos, P.; Peeters, F.M. |
| Title |
Single-layer and bilayer graphene superlattices: collimation, additional Dirac points and Dirac lines |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Philosophical transactions of the Royal Society : mathematical, physical and engineering sciences |
Abbreviated Journal |
Philos T R Soc A |
| Volume |
368 |
Issue |
1932 |
Pages |
5499-5524 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We review the energy spectrum and transport properties of several types of one-dimensional superlattices (SLs) on single-layer and bilayer graphene. In single-layer graphene, for certain SL parameters an electron beam incident on an SL is highly collimated. On the other hand, there are extra Dirac points generated for other SL parameters. Using rectangular barriers allows us to find analytical expressions for the location of new Dirac points in the spectrum and for the renormalization of the electron velocities. The influence of these extra Dirac points on the conductivity is investigated. In the limit of δ-function barriers, the transmission T through and conductance G of a finite number of barriers as well as the energy spectra of SLs are periodic functions of the dimensionless strength P of the barriers, Graphic, with vF the Fermi velocity. For a KronigPenney SL with alternating sign of the height of the barriers, the Dirac point becomes a Dirac line for P = π/2+nπ with n an integer. In bilayer graphene, with an appropriate bias applied to the barriers and wells, we show that several new types of SLs are produced and two of them are similar to type I and type II semiconductor SLs. Similar to single-layer graphene SLs, extra Dirac points are found in bilayer graphene SLs. Non-ballistic transport is also considered. |
| Address |
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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 |
|
| Language |
|
Wos |
000283660000011 |
Publication Date |
2010-11-01 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1364-503X;1471-2962; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.97 |
Times cited |
64 |
Open Access |
|
| Notes |
; This work was supported by IMEC, the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP) and the Canadian NSERC through grant no. OGP0121756. ; |
Approved |
Most recent IF: 2.97; 2010 IF: 2.459 |
| Call Number |
UA @ lucian @ c:irua:85597 |
Serial |
3023 |
| Permanent link to this record |
| |
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| |
| Author |
Van Holsbeke, C.S.; Verhulst, S.L.; Vos, W.G.; de Backer, J.W.; Vinchurkar, S.C.; Verdonck, P.R.; van Doorn, J.W.D.; Nadjmi, N.; de Backer, W.A. |
| Title |
Change in upper airway geometry between upright and supine position during tidal nasal breathing |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
Journal Of Aerosol Medicine And Pulmonary Drug Delivery |
Abbreviated Journal |
J Aerosol Med Pulm D |
| Volume |
27 |
Issue |
1 |
Pages |
51-57 |
| Keywords |
A1 Journal article; Biophysics and Biomedical Physics; Condensed Matter Theory (CMT); Laboratory Experimental Medicine and Pediatrics (LEMP); Translational Neurosciences (TNW) |
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000331144500007 |
Publication Date |
2013-03-19 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1941-2711;1941-2703; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.528 |
Times cited |
16 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 2.528; 2014 IF: 2.798 |
| Call Number |
UA @ lucian @ c:irua:115759 |
Serial |
308 |
| Permanent link to this record |
| |
|
| |
| Author |
Szaszko-Bogar, V.; Foeldi, P.; Peeters, F.M. |
| Title |
Oscillating spin-orbit interaction as a source of spin-polarized wavepackets in two-terminal nanoscale devices |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
| Volume |
26 |
Issue |
13 |
Pages |
135302 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Ballistic transport through nanoscale devices with time-dependent Rashba-type spin- orbit interaction (SOI) can lead to spin-polarized wavepackets that appear even for completely unpolarized input. The SOI that oscillates in a finite domain generates density and spin polarization fluctuations that leave the region as propagating waves. In particular, spin polarization has space and time dependence even in regions without SOI. Our results are based on an analytical solution of the time-dependent Schrodinger equation. The relevant Floquet quasi-energies that are obtained appear in the energy spectrum of both the transmitted and the reflected waves. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
London |
Editor |
|
| Language |
|
Wos |
|
Publication Date |
0000-00-00 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.649 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.649; 2014 IF: 2.346 |
| Call Number |
UA @ lucian @ c:irua:116844 |
Serial |
2533 |
| Permanent link to this record |
| |
|
| |
| Author |
Yorulmaz, U.; Demiroglu, I.; Cakir, D.; Gulseren, O.; Sevik, C. |
| Title |
A systematicalab-initioreview of promising 2D MXene monolayers towards Li-ion battery applications |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
JPhys Energy |
Abbreviated Journal |
|
| Volume |
2 |
Issue |
3 |
Pages |
032006 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| Abstract |
Two-dimensional materials have been attracting increasing interests because of their outstanding properties for Lithium-ion battery applications. In particular, a material family called MXenes (Mn+1Cn, where n = 1, 2, 3) have been recently attracted immense interest in this respect due to their incomparable fast-charging properties and high capacity promises. In this article, we review the state-of-the-art computational progress on Li-ion battery applications of MXene materials in accordance with our systematical DFT calculations. Structural, mechanical, dynamical, and electrical properties of 20 distinct MXene (M: Sc, Ti, V, Cr, Nb, Mo, Hf, Ta, W, and Zr) have been discussed. The battery performances of these MXene monolayers are further investigated by Li-ion binding energies, open circuit voltage values, and Li migration energy barriers. The experimental and theoretical progress up to date demonstrates particularly the potential of non-terminated or pristine MXene materials in Li ion-storage applications. Stability analyses show most of the pristine MXenes should be achievable, however susceptible to the development progress on the experimental growth procedures. Among pristine MXenes, Ti2C, V2C, Sc2C, and Zr2C compounds excel with their high charge/discharge rate prospect due to their extremely low Li diffusion energy barriers. Considering also their higher predicted gravimetric capacities, Sc, Ti, V, and Zr containing MXenes are more promising for their utilization in energy storage applications. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000569868600001 |
Publication Date |
2020-07-16 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2515-7655 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
6.9 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 6.9; 2020 IF: NA |
| Call Number |
UA @ admin @ c:irua:193748 |
Serial |
7399 |
| Permanent link to this record |
| |
|
| |
| Author |
Gul, A.; Bacaksiz, C.; Unsal, E.; Akbali, B.; Tomak, A.; Zareie, H.M.; Sahin, H. |
| Title |
Theoretical and experimental investigation of conjugation of 1,6-hexanedithiol on MoS2 |
Type |
A1 Journal article |
| Year |
2018 |
Publication |
Materials Research Express |
Abbreviated Journal |
Mater Res Express |
| Volume |
5 |
Issue |
3 |
Pages |
036415 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We report an experimental and theoretical investigation of conjugation of 1,6-Hexaneditihiol (HDT) on MoS2 which is prepared by mixing MoS2 structure and HDT molecules in proper solvent. Raman spectra and the calculated phonon bands reveal that the HDT molecules bind covalently to MoS2. Surface morphology of MoS2/HDTstructure is changed upon conjugation ofHDTon MoS2 and characterized by using Scanning Electron Microscope (SEM). Density Functional Theory (DFT) based calculations show that HOMO-LUMO band gap of HDT is altered after the conjugation and two-S binding (handle-like) configuration is energetically most favorable among three different structures. This study displays that the facile thiol functionalization process of MoS2 is promising strategy for obtaining solution processable MoS2. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
IOP Publishing |
Place of Publication |
Bristol |
Editor |
|
| Language |
|
Wos |
000428781400003 |
Publication Date |
2018-03-07 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2053-1591 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.068 |
Times cited |
2 |
Open Access |
|
| Notes |
; Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). HS acknowledges financial support from the TUBITAK under the project number 116C073. HS acknowledges support from Bilim Akademisi-The Science Academy, Turkey under the BAGEP program. ; |
Approved |
Most recent IF: 1.068 |
| Call Number |
UA @ lucian @ c:irua:154607UA @ admin @ c:irua:154607 |
Serial |
5133 |
| Permanent link to this record |
| |
|
| |
| Author |
Yorulmaz, U.; Šabani, D.; Sevik, C.; Milošević, M.V. |
| Title |
Goodenough-Kanamori-Anderson high-temperature ferromagnetism in tetragonal transition-metal xenes |
Type |
A1 Journal article |
| Year |
2024 |
Publication |
2D materials |
Abbreviated Journal |
|
| Volume |
11 |
Issue |
3 |
Pages |
035013-10 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Seminal Goodenough-Kanamori-Anderson (GKA) rules provide an inceptive understanding of the superexchange interaction of two magnetic metal ions bridged with an anion, and suggest fostered ferromagnetic interaction for orthogonal bridging bonds. However, there are no examples of two-dimensional (2D) materials with structure that optimizes the GKA arguments towards enhanced ferromagnetism and its critical temperature. Here we reveal that an ideally planar GKA ferromagnetism is indeed stable in selected tetragonal transition-metal xenes (tTMXs), with Curie temperature above 300 K found in CrC and MnC. We provide the general orbitally-resolved analysis of magnetic interactions that supports the claims and sheds light at the mechanisms dominating the magnetic exchange process in these structures. Furthermore, we propose the set of three GKA-like rules that will guarantee room temperature ferromagetnism. With recent advent of epitaxially-grown tetragonal 2D materials, our findings earmark tTMXs for facilitated spintronic and magnonic applications, or as a desirable magnetic constituent of functional 2D heterostructures. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
001208053200001 |
Publication Date |
2024-04-12 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2053-1583 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
no |
| Call Number |
UA @ admin @ c:irua:205464 |
Serial |
9153 |
| Permanent link to this record |
| |
|
| |
| Author |
Pandey, T.; Peeters, F.M.; Milošević, M.V. |
| Title |
Pivotal role of magnetic ordering and strain in lattice thermal conductivity of chromium-trihalide monolayers |
Type |
A1 Journal article |
| Year |
2022 |
Publication |
2D materials |
Abbreviated Journal |
2D Mater |
| Volume |
9 |
Issue |
1 |
Pages |
015034 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Understanding the coupling between spin and phonons is critical for controlling the lattice thermal conductivity (kappa ( l )) in magnetic materials, as we demonstrate here for CrX3 (X = Br and I) monolayers. We show that these compounds exhibit large spin-phonon coupling (SPC), dominated by out-of-plane vibrations of Cr atoms, resulting in significantly different phonon dispersions in ferromagnetic (FM) and paramagnetic (PM) phases. Lattice thermal conductivity calculations provide additional evidence for strong SPC, where particularly large kappa ( l ) is found for the FM phase. Most strikingly, PM and FM phases exhibit radically different behavior with tensile strain, where kappa ( l ) increases with strain for the PM phase, and strongly decreases for the FM phase-as we explain through analysis of phonon lifetimes and scattering rates. Taken all together, we uncover the high significance of SPC on the phonon transport in CrX3 monolayers, a result extendable to other 2D magnetic materials, that will be useful in further design of thermal spin devices. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000735170300001 |
Publication Date |
2021-12-13 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2053-1583 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
5.5 |
Times cited |
|
Open Access |
Not_Open_Access |
| Notes |
|
Approved |
Most recent IF: 5.5 |
| Call Number |
UA @ admin @ c:irua:184642 |
Serial |
7010 |
| Permanent link to this record |
| |
|
| |
| Author |
Bacaksiz, C.; Yagmurcukardes, M.; Peeters, F.M.; Milošević, M.V. |
| Title |
Hematite at its thinnest limit |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
2d Materials |
Abbreviated Journal |
2D Mater |
| Volume |
7 |
Issue |
2 |
Pages |
025029 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Motivated by the recent synthesis of two-dimensional alpha-Fe2O3 (Balan et al 2018 Nat. Nanotechnol. 13 602), we analyze the structural, vibrational, electronic and magnetic properties of single- and few-layer alpha-Fe2O3 compared to bulk, by ab initio and Monte-Carlo simulations. We reveal how monolayer alpha-Fe2O3 (hematene) can be distinguished from the few-layer structures, and how they all differ from bulk through observable Raman spectra. The optical spectra exhibit gradual shift of the prominent peak to higher energy, as well as additional features at lower energy when alpha-Fe2O3 is thinned down to a monolayer. Both optical and electronic properties have strong spin asymmetry, meaning that lower-energy optical and electronic activities are allowed for the single-spin state. Finally, our considerations of magnetic properties reveal that 2D hematite has anti-ferromagnetic ground state for all thicknesses, but the critical temperature for Morin transition increases with decreasing sample thickness. On all accounts, the link to available experimental data is made, and further measurements are prompted. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000537341000002 |
Publication Date |
2020-01-20 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2053-1583 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
5.5 |
Times cited |
11 |
Open Access |
|
| Notes |
; This work was supported by Research Foundation-Flanders (FWO-Vlaanderen). Computational resources were provided by Flemish Supercomputer Center(VSC), and TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). Part of this work was also supported by FLAG-ERA project TRANS-2D-TMD and TOPBOF-UAntwerp. MY was supported by a postdoctoral fellowship from the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 5.5; 2020 IF: 6.937 |
| Call Number |
UA @ admin @ c:irua:170301 |
Serial |
6533 |
| Permanent link to this record |
| |
|
| |
| Author |
Van Pottelberge, R.; Moldovan, D.; Milovanović, S.P.; Peeters, F.M. |
| Title |
Molecular collapse in monolayer graphene |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
2D materials |
Abbreviated Journal |
2D Mater |
| Volume |
6 |
Issue |
4 |
Pages |
045047 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Atomic collapse is a phenomenon inherent to relativistic quantum mechanics where electron states dive in the positron continuum for highly charged nuclei. This phenomenon was recently observed in graphene. Here we investigate a novel collapse phenomenon when multiple sub- and supercritical charges of equal strength are put close together as in a molecule. We construct a phase diagram which consists of three distinct regions: (1) subcritical, (2) frustrated atomic collapse, and (3) molecular collapse. We show that the single impurity atomic collapse resonances rearrange themselves to form molecular collapse resonances which exhibit a distinct bonding, anti-bonding and non-bonding character. Here we limit ourselves to systems consisting of two and three charges. We show that by tuning the distance between the charges and their strength a high degree of control over the molecular collapse resonances can be achieved. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000487692200003 |
Publication Date |
2019-08-30 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2053-1583 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
6.937 |
Times cited |
6 |
Open Access |
|
| Notes |
; We thank Matthias Van der Donck for fruitful discussions. This work was supported by the Research Foundation of Flanders (FWO-V1) through an aspirant research Grant for RVP and a postdoctoral Grant for SPM. ; |
Approved |
Most recent IF: 6.937 |
| Call Number |
UA @ admin @ c:irua:163756 |
Serial |
5422 |
| Permanent link to this record |
| |
|
| |
| Author |
Sevik, C.; Wallbank, J.R.; Gulseren, O.; Peeters, F.M.; Çakir, D. |
| Title |
Gate induced monolayer behavior in twisted bilayer black phosphorus |
Type |
A1 Journal article |
| Year |
2017 |
Publication |
2D materials |
Abbreviated Journal |
2D Mater |
| Volume |
4 |
Issue |
3 |
Pages |
035025 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Optical and electronic properties of black phosphorus strongly depend on the number of layers and type of stacking. Using first-principles calculations within the framework of density functional theory, we investigate the electronic properties of bilayer black phosphorus with an interlayer twist angle of 90 degrees. These calculations are complemented with a simple (k) over right arrow . (p) over right arrow model which is able to capture most of the low energy features and is valid for arbitrary twist angles. The electronic spectrum of 90 degrees twisted bilayer black phosphorus is found to be x-y isotropic in contrast to the monolayer. However x-y anisotropy, and a partial return to monolayer-like behavior, particularly in the valence band, can be induced by an external out-of-plane electric field. Moreover, the preferred hole effective mass can be rotated by 90 degrees simply by changing the direction of the applied electric field. In particular, a +0.4 (-0.4) V angstrom(1) out-of-plane electric field results in a similar to 60% increase in the hole effective mass along the y (x) axis and enhances the m(y)*/m(x)* (m(x)*/m(y)*) ratio as much as by a factor of 40. Our DFT and (k) over right arrow . (p) over right arrow simulations clearly indicate that the twist angle in combination with an appropriate gate voltage is a novel way to tune the electronic and optical properties of bilayer phosphorus and it gives us a new degree of freedom to engineer the properties of black phosphorus based devices. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
IOP Publishing |
Place of Publication |
Bristol |
Editor |
|
| Language |
|
Wos |
000406926600001 |
Publication Date |
2017-08-03 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2053-1583 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
6.937 |
Times cited |
13 |
Open Access |
|
| Notes |
; This work was supported by the bilateral project between the The Scientific and Technological Research Council of Turkey (TUBITAK) and FWO-Flanders, Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TRGrid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. We acknowledge the support from TUBITAK (Grant No. 115F024), ERC Synergy grant Hetero2D and the EU Graphene Flagship Project. We also thank Vladimir Fal'ko for helpful discussions. ; |
Approved |
Most recent IF: 6.937 |
| Call Number |
UA @ lucian @ c:irua:145151 |
Serial |
4717 |
| Permanent link to this record |
| |
|
| |
| 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 |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
IOP Publishing |
Place of Publication |
Bristol |
Editor |
|
| Language |
|
Wos |
000424399600005 |
Publication Date |
2017-02-02 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2053-1583 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
6.937 |
Times cited |
16 |
Open Access |
|
| 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 |
| |
|
| |
| Author |
Saniz, R.; Vercauteren, S.; Lamoen, D.; Partoens, B.; Barbiellini, B. |
| Title |
Accurate description of the van der Waals interaction of an electron-positron pair with the surface of a topological insulator |
Type |
P1 Proceeding |
| Year |
2014 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
|
| Volume |
505 |
Issue |
|
Pages |
012002 |
| Keywords |
P1 Proceeding; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
| Abstract |
Positrons can be trapped in localized states at the surface of a material, and thus quite selectively interact with core or valence surface electrons. Hence, advanced surface positron spectroscopy techniques can present the ideal tools to study a topological insulator, where surface states play a fundamental role. We analyze the problem of a positron at a TI surface, assuming that it is a weakly physisorbed positronium (Ps) atom. To determine if the surface of interest in a material can sustain such a physisorption, an accurate description of the underlying van der Waals (vdW) interaction is essential. We have developed a first-principles parameterfree method, based on the density functional theory, to extract key parameters determining the vdW interaction potential between a Ps atom and the surface of a given material. The method has been successfully applied to quartz and preliminary results on Bi2Te2Se indicate the existence of a positron surface state. We discuss the robustness of our predictions versus the most relevant approximations involved in our approach. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Bristol |
Editor |
|
| Language |
|
Wos |
000338216500002 |
Publication Date |
2014-04-28 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1742-6588;1742-6596; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
2 |
Open Access |
|
| Notes |
; We thank A. Weiss for very useful conversations. We acknowledge financial support from FWO-Vlaanderen (projectG.0150.13). This work was carried out using the HPC infrastructure of the University of Antwerp (CalcUA), adivision of the Flemish Supercomputer Center (VSC), funded by the Hercules foundation and the Flemish Government (EWI Department). B. B. is supported by DOE grants Nos. DE-FG02-07ER46352 and DE-AC02-05CH11231 for theory support at ALS, Berkeley, and a NERSC computer time allocation. ; |
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:118264 |
Serial |
46 |
| Permanent link to this record |
| |
|
| |
| Author |
Engbarth, M.; Milošević, M.V.; Bending, S.J.; Nasirpouri, F. |
| Title |
Geometry-guided flux behaviour in superconducting Pb microcrystals |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
|
| Volume |
150 |
Issue |
5 |
Pages |
052048 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Electrochemistry offers highly flexible routes to fabrication of a wide variety of mesostructures, including three-dimensional (3D) crystallites, thin films and nanowires. Using this method we have grown various 3D superconducting Pb mesostructures with vastly different morphologies. We present here results on a truncated(half)-icosahedron with a hexagonal base and a tripod structure with a triangular base. Using Hall probe magnetometry we have obtained magnetisation curves for these structures at several temperatures and see evidence of geometry-driven flux entry and exit as well as flux trapping caused by specific sample geometries. We also observe behaviour that we interpret in terms of the formation of giant vortices, bearing in mind that bulk Pb is a type-I superconducting material. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Bristol |
Editor |
|
| Language |
|
Wos |
|
Publication Date |
2009-04-01 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1742-6588;1742-6596; |
ISBN |
|
Additional Links |
UA library record |
| Impact Factor |
|
Times cited |
1 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:106138 |
Serial |
1332 |
| Permanent link to this record |
| |
|
| |
| Author |
Zamani, M.; Yapicioglu, H.; Kara, A.; Sevik, C. |
| Title |
Statistical analysis of porcelain tiles' technical properties : full factorial design investigation on oxide ratios and temperature |
Type |
A1 Journal article |
| Year |
2023 |
Publication |
Physica scripta |
Abbreviated Journal |
|
| Volume |
98 |
Issue |
12 |
Pages |
125953-18 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
This study focuses on optimizing the composition and firing temperature of porcelain tiles using statistical analysis techniques. A full factorial design, including model adequacy checking, analysis of variance, Pareto charts, interaction plots, regression model, and response optimizer is employed. The key factors were the Seger ratios of SiO2/Al2O3, Na2O/K2O, MgO/CaO, and firing temperature. The response variables investigated were bulk density, water absorption, linear shrinkage, coefficient of thermal expansion (at 500 degrees C), and strength. The statistical analysis revealed highly significant results, which were further validated, confirming their reliability for practical use in the production of porcelain tiles. The study demonstrated the effectiveness of utilizing Seger formulas and properties of typical raw materials to accurately predict the final properties of ceramic tiles. By employing SiO2/Al2O3 = 5.2, Na2O/K2O = 1.50, MgO/CaO = 3.0, and firing temperature of 1180 degrees C, optimized properties, such as maximum strength, maximum bulk density, and minimum water absorption, was achieved with a composite desirability of 0.9821. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
001105879800001 |
Publication Date |
2023-11-08 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0031-8949; 1402-4896 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| Impact Factor |
2.9 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.9; 2023 IF: 1.28 |
| Call Number |
UA @ admin @ c:irua:202033 |
Serial |
9097 |
| Permanent link to this record |
| |
|
| |
| Author |
Becker, T.; Nelissen, K.; Cleuren, B. |
| Title |
Current fluctuations in boundary driven diffusive systems in different dimensions : a numerical study |
Type |
A1 Journal article |
| Year |
2015 |
Publication |
New journal of physics |
Abbreviated Journal |
New J Phys |
| Volume |
17 |
Issue |
17 |
Pages |
055023 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We use kinetic Monte Carlo simulations to investigate current fluctuations in boundary driven generalized exclusion processes, in different dimensions. Simulation results are in full agreement with predictions based on the additivity principle and the macroscopic fluctuation theory. The current statistics are independent of the shape of the contacts with the reservoirs, provided they are macroscopic in size. In general, the current distribution depends on the spatial dimension. For the special cases of the symmetric simple exclusion process and the zero-range process, the current statistics are the same for all spatial dimensions. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Bristol |
Editor |
|
| Language |
|
Wos |
000355282700001 |
Publication Date |
2015-05-27 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1367-2630; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.786 |
Times cited |
5 |
Open Access |
|
| Notes |
; We thank Christian Van den Broeck for bringing this problem to our attention. We are grateful to Bart Partoens and Carlo Vanderzande for a careful reading of the manuscript. This work was supported by the Flemish Science Foundation (Fonds Wetenschappelijk Onderzoek), Project No. G038811N. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Hercules Foundation and the Flemish Government-department EWI. ; |
Approved |
Most recent IF: 3.786; 2015 IF: 3.558 |
| Call Number |
c:irua:126405 |
Serial |
592 |
| Permanent link to this record |
| |
|
| |
| Author |
Linek, J.; Wyszynski, M.; Müller, B.; Korinski, D.; Milošević, M.V.; Kleiner, R.; Koelle, D. |
| Title |
On the coupling of magnetic moments to superconducting quantum interference devices |
Type |
A1 Journal article |
| Year |
2024 |
Publication |
Superconductor science and technology |
Abbreviated Journal |
|
| Volume |
37 |
Issue |
2 |
Pages |
025010-25012 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We investigate the coupling factor phi( mu) that quantifies the magnetic flux phi per magnetic moment mu of a point-like magnetic dipole that couples to a superconducting quantum interference device (SQUID). Representing the dipole by a tiny current-carrying (Amperian) loop, the reciprocity of mutual inductances of SQUID and Amperian loop provides an elegant way of calculating phi(mu)(r,e(mu)) vs. position r and orientation e(mu) of the dipole anywhere in space from the magnetic field B-J(r) produced by a supercurrent circulating in the SQUID loop. We use numerical simulations based on London and Ginzburg-Landau theory to calculate phi (mu) from the supercurrent density distributions in various superconducting loop geometries. We treat the far-field regime ( r greater than or similar to a= inner size of the SQUID loop) with the dipole placed on (oriented along) the symmetry axis of circular or square shaped loops. We compare expressions for phi (mu) from simple filamentary loop models with simulation results for loops with finite width w (outer size A > alpha), thickness d and London penetration depth lambda(L )and show that for thin ( d << alpha ) and narrow (w < alpha) loops the introduction of an effective loop size a(eff) in the filamentary loop-model expressions results in good agreement with simulations. For a dipole placed right in the center of the loop, simulations provide an expression phi(mu)(a,A,d,lambda(L)) that covers a wide parameter range. In the near-field regime (dipole centered at small distance z above one SQUID arm) only coupling to a single strip representing the SQUID arm has to be considered. For this case, we compare simulations with an analytical expression derived for a homogeneous current density distribution, which yields excellent agreement for lambda(L)>w,d . Moreover, we analyze the improvement of phi(mu) provided by the introduction of a narrow constriction in the SQUID arm below the magnetic dipole. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
001145725500001 |
Publication Date |
2024-01-04 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0953-2048 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| Impact Factor |
3.6 |
Times cited |
|
Open Access |
Not_Open_Access |
| Notes |
|
Approved |
Most recent IF: 3.6; 2024 IF: 2.878 |
| Call Number |
UA @ admin @ c:irua:202759 |
Serial |
9067 |
| Permanent link to this record |
| |
|
| |
| 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. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000577207000001 |
Publication Date |
2020-09-16 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0953-2048 |
ISBN |
|
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 |
| |
|
| |
| Author |
Zebrowski, D.P.; Peeters, F.M.; Szafran, B. |
| Title |
Driven spin transitions in fluorinated single- and bilayer-graphene quantum dots |
Type |
A1 Journal article |
| Year |
2017 |
Publication |
Semiconductor science and technology |
Abbreviated Journal |
Semicond Sci Tech |
| Volume |
32 |
Issue |
6 |
Pages |
065016 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Spin transitions driven by a periodically varying electric potential in dilute fluorinated graphene quantum dots are investigated. Flakes of monolayer graphene as well as electrostatic electron traps induced in bilayer graphene are considered. The stationary states obtained within the tight-binding approach are used as the basis for description of the system dynamics. The dilute fluorination of the top layer lifts the valley degeneracy of the confined states and attenuates the orbital magnetic dipole moments due to current circulation within the flake. The spin-orbit coupling introduced by the surface deformation of the top layer induced by the adatoms allows the spin flips to be driven by the AC electric field. For the bilayer quantum dots the spin flip times is substantially shorter than the spin relaxation. Dynamical effects including many-photon and multilevel transitions are also discussed. |
| Address |
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| Corporate Author |
|
Thesis |
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| Publisher |
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Place of Publication |
London |
Editor |
|
| Language |
|
Wos |
000402405800007 |
Publication Date |
2017-04-19 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0268-1242 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| Impact Factor |
2.305 |
Times cited |
|
Open Access |
|
| Notes |
; This work was supported by the National Science Centre according to decision DEC-2013/11/B/ST3/03837 and by the Flemish Science Foundation (FWO-VL). ; |
Approved |
Most recent IF: 2.305 |
| Call Number |
UA @ lucian @ c:irua:144238 |
Serial |
4646 |
| Permanent link to this record |
| |
|
| |
| Author |
Osca, J.; Moors, K.; Sorée, B.; Serra, L. |
| Title |
Fabry-Perot interferometry with gate-tunable 3D topological insulator nanowires |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Nanotechnology |
Abbreviated Journal |
Nanotechnology |
| Volume |
32 |
Issue |
43 |
Pages |
435002 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| Abstract |
Three-dimensional topological insulator (3D TI) nanowires display remarkable magnetotransport properties that can be attributed to their spin-momentum-locked surface states such as quasiballistic transport and Aharonov-Bohm oscillations. Here, we focus on the transport properties of a 3D TI nanowire with a gated section that forms an electronic Fabry-Perot (FP) interferometer that can be tuned to act as a surface-state filter or energy barrier. By tuning the carrier density and length of the gated section of the wire, the interference pattern can be controlled and the nanowire can become fully transparent for certain topological surface-state input modes while completely filtering out others. We also consider the interplay of FP interference with an external magnetic field, with which Klein tunneling can be induced, and transverse asymmetry of the gated section, e.g. due to a top-gated structure, which displays an interesting analogy with Rashba nanowires. Due to its rich conductance phenomenology, we propose a 3D TI nanowire with gated section as an ideal setup for a detailed transport-based characterization of 3D TI nanowire surface states near the Dirac point, which could be useful towards realizing 3D TI nanowire-based topological superconductivity and Majorana bound states. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000682173800001 |
Publication Date |
2021-07-20 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0957-4484 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.44 |
Times cited |
|
Open Access |
Not_Open_Access |
| Notes |
|
Approved |
Most recent IF: 3.44 |
| Call Number |
UA @ admin @ c:irua:180487 |
Serial |
6990 |
| Permanent link to this record |
| |
|
| |
| Author |
Zhang, R.; Wu, Z.; Li, X.J.; Li, L.L.; Chen, Q.; Li, Y.-M.; Peeters, F.M. |
| Title |
Fano resonances in bilayer phosphorene nanoring |
Type |
A1 Journal article |
| Year |
2018 |
Publication |
Nanotechnology |
Abbreviated Journal |
Nanotechnology |
| Volume |
29 |
Issue |
21 |
Pages |
215202 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| Abstract |
Tunable transport properties and Fano resonances are predicted in a circular bilayer phosphorene nanoring. The conductance exhibits Fano resonances with varying incident energy and applied perpendicular magnetic field. These Fano resonance peaks can be accurately fitted with the well known Fano curves. When a magnetic field is applied to the nanoring, the conductance oscillates periodically with magnetic field which is reminiscent of the Aharonov-Bohm effect. Fano resonances are tightly related to the discrete states in the central nanoring, some of which are tunable by the magnetic field. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Bristol |
Editor |
|
| Language |
|
Wos |
000428920200001 |
Publication Date |
2018-03-08 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0957-4484 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.44 |
Times cited |
4 |
Open Access |
|
| Notes |
; This work was supported by Grant No. 2017YFA0303400 from the National Key R&D Program of China, the Flemish Science Foundation, the grants No. 2016YFE0110000, No. 2015CB921503, and No. 2016YFA0202300 from the MOST of China, the NSFC (Grants Nos. 11504366, 11434010, 61674145 and 61774168) and CAS (Grants No. QYZDJ-SSW-SYS001). ; |
Approved |
Most recent IF: 3.44 |
| Call Number |
UA @ lucian @ c:irua:150713UA @ admin @ c:irua:150713 |
Serial |
4968 |
| Permanent link to this record |
