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Author |
McNaughton, B.; Milošević, M.V.; Perali, A.; Pilati, S. |
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Title |
Boosting Monte Carlo simulations of spin glasses using autoregressive neural networks |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Physical Review E |
Abbreviated Journal |
Phys Rev E |
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Volume |
101 |
Issue |
5 |
Pages |
053312 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The autoregressive neural networks are emerging as a powerful computational tool to solve relevant problems in classical and quantum mechanics. One of their appealing functionalities is that, after they have learned a probability distribution from a dataset, they allow exact and efficient sampling of typical system configurations. Here we employ a neural autoregressive distribution estimator (NADE) to boost Markov chain Monte Carlo (MCMC) simulations of a paradigmatic classical model of spin-glass theory, namely, the two-dimensional Edwards-Anderson Hamiltonian. We show that a NADE can be trained to accurately mimic the Boltzmann distribution using unsupervised learning from system configurations generated using standard MCMC algorithms. The trained NADE is then employed as smart proposal distribution for the Metropolis-Hastings algorithm. This allows us to perform efficient MCMC simulations, which provide unbiased results even if the expectation value corresponding to the probability distribution learned by the NADE is not exact. Notably, we implement a sequential tempering procedure, whereby a NADE trained at a higher temperature is iteratively employed as proposal distribution in a MCMC simulation run at a slightly lower temperature. This allows one to efficiently simulate the spin-glass model even in the low-temperature regime, avoiding the divergent correlation times that plague MCMC simulations driven by local-update algorithms. Furthermore, we show that the NADE-driven simulations quickly sample ground-state configurations, paving the way to their future utilization to tackle binary optimization problems. |
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Wos |
000535862000014 |
Publication Date |
2020-05-28 |
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Series Issue |
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Edition |
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ISSN |
1539-3755; 1550-2376 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.366 |
Times cited |
15 |
Open Access |
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Notes |
; The authors thank I. Murray, G. Carleo, and F. RicciTersenghi for useful discussions. Financial support from the FAR2018 project titled “Supervised machine learning for quantum matter and computational docking” of the University of Camerino and from the Italian MIUR under Project No. PRIN2017 CEnTraL 20172H2SC4 is gratefully acknowledged. S.P. also acknowledges the CINECA award under the ISCRA initiative, for the availability of high performance computing resources and support. M.V.M. gratefully acknowledges the Visiting Professorship program at the University of Camerino that facilitated the collaboration in this work. ; |
Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:170244 |
Serial |
6463 |
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Permanent link to this record |
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Author |
Mirzakhani, M.; Peeters, F.M.; Zarenia, M. |
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Title |
Circular quantum dots in twisted bilayer graphene |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
101 |
Issue |
7 |
Pages |
075413 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Within a tight-binding approach, we investigate the effect of twisting angle on the energy levels of circular bilayer graphene (BLG) quantum dots (QDs) in both the absence and presence of a perpendicular magnetic field. The QDs are defined by an infinite-mass potential, so that the specific edge effects are not present. In the absence of magnetic field (or when the magnetic length is larger than the moire length), we show that the low-energy states in twisted BLG QDs are completely affected by the formation of moire patterns, with a strong localization at AA-stacked regions. When magnetic field increases, the energy gap of an untwisted BLG QD closes with the edge states, localized at the boundaries between the AA- and AB-stacked spots in a twisted BLG QD. Our observation of the spatial localization of the electrons in twisted BLG QDs can be experimentally probed by low-bias scanning tunneling microscopy measurements. |
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Wos |
000512772200004 |
Publication Date |
2020-02-13 |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.7 |
Times cited |
19 |
Open Access |
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Notes |
; We gratefully acknowledge discussions with I. Snyman. M.Z. acknowledges support from the U.S. Department of Energy (Office of Science) under Grant No. DE-FG0205ER46203. ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:166493 |
Serial |
6470 |
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Author |
Vargas Paredes, A.A.; Shanenko, A.A.; Vagov, A.; Milošević, M.V.; Perali, A. |
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Title |
Crossband versus intraband pairing in superconductors: signatures and consequences of the interplay |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
101 |
Issue |
9 |
Pages |
094516-94517 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We analyze the paradigmatic competition between intraband and crossband Cooper-pair formation in twoband superconductors, neglected in most works to date. We derive the phase-sensitive gap equations and describe the crossover between the intraband-dominated and the crossband-dominated regimes, delimited by a “gapless” state. Experimental signatures of crosspairing comprise notable gap splitting in the excitation spectrum, non-BCS behavior of gaps versus temperature, as well as changes in the pairing symmetry as a function of temperature. The consequences of these findings are illustrated on the examples of MgB2 and Ba0.6K0.4Fe2As2. |
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Wos |
000522074900002 |
Publication Date |
2020-03-27 |
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Abbreviated Series Title |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.7 |
Times cited |
14 |
Open Access |
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Notes |
; This collaborative work was fostered within the international Multi Super network on Multi-condensate Superconductivity and Superfluidity [70]. The authors thank Andrea Guidini for his help during the initial stage of this work and Laura Fanfarillo for useful discussions. This work was partially supported by the Italian MIUR through the PRIN 2015 program (Contract No. 2015C5SEJJ001) and the Research Foundation -Flanders (FWO). A.A.V.-P. acknowledges support by the joint doctoral program and by the Erasmus+ exchange between the University of Antwerp and the University of Camerino. M.V.M. gratefully acknowledges support from a Visiting Professorship at the University of Camerino. A.S. and A.V. acknowledge support from the CAPES/Print Grant, Process No. 88887.333666/ 2019-00 (Brazil) and the Russian Science Foundation Project No. 18-12-00429, respectively. ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:168605 |
Serial |
6479 |
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Permanent link to this record |
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Author |
Conti, S.; Van der Donck, M.; Perali, A.; Peeters, F.M.; Neilson, D. |
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Title |
Doping-dependent switch from one- to two-component superfluidity in coupled electron-hole van der Waals heterostructures |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
101 |
Issue |
22 |
Pages |
220504-220506 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The hunt for high-temperature superfluidity has received new impetus from the discovery of atomically thin stable materials. Electron-hole superfluidity in coupled MoSe2-WSe2 monolayers is investigated using a mean-field multiband model that includes band splitting caused by strong spin-orbit coupling. This splitting leads to a large energy misalignment of the electron and hole bands which is strongly modified by interchanging the doping of the monolayers. The choice of doping determines if the superfluidity is tunable from one to two components. |
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Wos |
000538941900002 |
Publication Date |
2020-06-09 |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.7 |
Times cited |
12 |
Open Access |
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Notes |
; This work was partially supported by the Fonds Wetenschappelijk Onderzoek (FWO-Vl), the Methusalem Foundation, and the FLAG-ERA project TRANS2DTMD. We thank A. R. Hamilton and A. Vargas-Paredes for useful discussions. ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:170201 |
Serial |
6489 |
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Author |
Saberi-Pouya, S.; Conti, S.; Perali, A.; Croxall, A.F.; Hamilton, A.R.; Peeters, F.M.; Neilson, D. |
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Title |
Experimental conditions for the observation of electron-hole superfluidity in GaAs heterostructures |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
101 |
Issue |
14 |
Pages |
140501-140506 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The experimental parameter ranges needed to generate superfluidity in optical and drag experiments in GaAs double quantum wells are determined using a formalism that includes self-consistent screening of the Coulomb pairing interaction in the presence of the superfluid. The very different electron and hole masses in GaAs make this a particularly interesting system for superfluidity with exotic superfluid phases predicted in the BCS-Bose-Einstein condensation crossover regime. We find that the density and temperature ranges for superfluidity cover the range for which optical experiments have observed indications of superfluidity but that existing drag experiments lie outside the superfluid range. We also show that, for samples with low mobility with no macroscopically connected superfluidity, if the superfluidity survives in randomly distributed localized pockets, standard quantum capacitance measurements could detect these pockets. |
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Wos |
000523627600001 |
Publication Date |
2020-04-06 |
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Abbreviated Series Title |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.7 |
Times cited |
18 |
Open Access |
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Notes |
; We thank K. Das Gupta, F. Dubin, U. Siciliani de Cumis, M. Pini, and J. Waldie for illuminating discus-sions. This work was partially supported by the Flemish Science Foundation (FWO-Vl) and the Australian Government through the Australian Research Council Centre of Excellence in Future Low-Energy Electronics (Project No. CE170100039). ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:168561 |
Serial |
6517 |
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Permanent link to this record |
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Author |
Li, L.L.; Bacaksiz, C.; Nakhaee, M.; Pentcheva, R.; Peeters, F.M.; Yagmurcukardes, M. |
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Title |
Single-layer Janus black arsenic-phosphorus (b-AsP): optical dichroism, anisotropic vibrational, thermal, and elastic properties |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
101 |
Issue |
13 |
Pages |
134102-134109 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
By using density functional theory (DFT) calculations, we predict a puckered, dynamically stable Janus single-layer black arsenic-phosphorus (b-AsP), which is composed of two different atomic sublayers, arsenic and phosphorus atoms. The calculated phonon spectrum reveals that Janus single-layer b-AsP is dynamically stable with either pure or coupled optical phonon branches arising from As and P atoms. The calculated Raman spectrum indicates that due to the relatively strong P-P bonds, As atoms have no contribution to the highfrequency optical vibrations. In addition, the orientation-dependent isovolume heat capacity reveals anisotropic contributions of LA and TA phonon branches to the low-temperature thermal properties. Unlike pristine single layers of b-As and b-P, Janus single-layer b-AsP exhibits additional out-of-plane asymmetry which leads to important consequences for its electronic, optical, and elastic properties. In contrast to single-layer b-As, Janus single-layer b-AsP is found to possess a direct band gap dominated by the P atoms. Moreover, real and imaginary parts of the dynamical dielectric function, including excitonic effects, reveal the highly anisotropic optical feature of the Janus single-layer. A tight-binding (TB) model is also presented for Janus single-layer b-AsP, and it is shown that, with up to seven nearest hoppings, the TB model reproduces well the DFT band structure in the low-energy region around the band gap. This TB model can be used in combination with the Green's function approach to study, e.g., quantum transport in finite systems based on Janus single-layer b-AsP. Furthermore, the linear-elastic properties of Janus single-layer b-AsP are investigated, and the orientation-dependent in-plane stiffness and Poisson ratio are calculated. It is found that the Janus single layer exhibits strong in-plane anisotropy in its Poisson ratio much larger than that of single-layer b-P. This Janus single layer is relevant for promising applications in optical dichroism and anisotropic nanoelasticity. |
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Wos |
000524531900001 |
Publication Date |
2020-04-09 |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.7 |
Times cited |
39 |
Open Access |
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Notes |
; This work was supported by the German Science Foundation (DFG) within SFB/TRR80 (project G3) and the FLAGERA project TRANS-2D-TMD. M.Y. was supported by a postdoctoral fellowship from the Flemish Science Foundation (FWO-Vl). Computational resources were provided by the Flemish Supercomputer Center (VSC) and Leibniz Supercomputer Centrum (project pr87ro). ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:168554 |
Serial |
6602 |
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Permanent link to this record |
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Author |
Zhang, L.; Zhang, Y.-Y.; Zha, G.-Q.; Milošević, M.V.; Zhou, S.-P. |
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Title |
Skyrmionic chains and lattices in s plus id superconductors |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
101 |
Issue |
6 |
Pages |
064501 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We report characteristic vortex configurations in s + id superconductors with time-reversal symmetry breaking, exposed to magnetic field. A vortex in the s + id state tends to have an opposite phase winding between s- and d-wave condensates. We find that this peculiar feature together with the competition between s- and d-wave symmetry results in three distinct classes of vortical configurations. When either s or d condensate absolutely dominates, vortices form a conventional lattice. However, when one condensate is relatively dominant, vortices organize in chains that exhibit skyrmionic character, separating the chiral components of the s +/- id order parameter into domains within and outside the chain. Such skyrmionic chains are found stable even at high magnetic field. When s and d condensates have comparable strength, vortices split cores in two chiral components to form full-fledged skyrmions, i.e., coreless topological structures with an integer topological charge, organized in a lattice. We provide characteristic magnetic field distributions of all states, enabling their identification in, e.g., scanning Hall probe and scanning SQUID experiments. These unique vortex states are relevant for high-T-c cuprate and iron-based superconductors, where the relative strength of competing pairing symmetries is expected to be tuned by temperature and/or doping level, and can help distinguish s + is and s + id superconducting phases. |
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Wos |
000510745600005 |
Publication Date |
2020-02-03 |
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Series Editor |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.7 |
Times cited |
7 |
Open Access |
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Notes |
; The authors acknowledge useful discussions with Yong-Ping Zhang. This research was supported by the National Natural Science Foundation of China under Grants No. 61571277 and No. 61771298. L.-F.Z. and M.V.M. acknowledge support from Research Foundation-Flanders (FWO-Vlaanderen). ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:166507 |
Serial |
6605 |
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Permanent link to this record |
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Author |
Menezes, R.M.; de Souza Silva, C.C.; Milošević, M.V. |
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Title |
Spin textures in chiral magnetic monolayers with suppressed nearest-neighbor exchange |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
101 |
Issue |
21 |
Pages |
214429-9 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
High tunability of two-dimensional magnetic materials (by strain, gating, heterostructuring, or otherwise) provides unique conditions for studying versatile magnetic properties and controlling emergent magnetic phases. Expanding the scope of achievable magnetic phenomena in such materials is important for both fundamental and technological advances. Here we perform atomistic spin-dynamics simulations to explore the (chiral) magnetic phases of atomic monolayers in the limit of suppressed first-neighbors exchange interaction. We report the rich phase diagram of exotic magnetic configurations, obtained for both square and honeycomb lattice symmetries, comprising coexistence of ferromagnetic and antiferromagnetic spin cycloids, as well as multiple types of magnetic skyrmions. We perform a minimum-energy path analysis for the skyrmion collapse to evaluate the stability of such topological objects and reveal that magnetic monolayers could be good candidates to host the antiferromagnetic skyrmions that are experimentally evasive to date. |
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Wos |
000540910100002 |
Publication Date |
2020-06-18 |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.7 |
Times cited |
1 |
Open Access |
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Notes |
; This work was supported by the Research Foundation-Flanders (FWO-Vlaanderen) and Brazilian Agencies FACEPE (under Grant No. APQ-0198-1.05/14), CAPES, and CNPq. ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:170176 |
Serial |
6610 |
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Permanent link to this record |
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Author |
Yagmurcukardes, M.; Peeters, F.M. |
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Title |
Stable single layer of Janus MoSO: strong out-of-plane piezoelectricity |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
101 |
Issue |
15 |
Pages |
155205-155208 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Using density functional theory based first-principles calculations, we predict the dynamically stable 1H phase of a Janus single layer composed of S-Mo-O atomic layers. It is an indirect band gap semiconductor exhibiting strong polarization arising from the charge difference on the two surfaces. In contrast to 1H phases of MoS2 and MoO2, Janus MoSO is found to possess four Raman active phonon modes and a large out-of-plane piezoelectric coefficient which is absent in fully symmetric single layers of MoS2 and MoO2. We investigated the electronic and phononic properties under applied biaxial strain and found an electronic phase transition with tensile strain while the conduction band edge displays a shift when under compressive strain. Furthermore, single-layer MoSO exhibits phononic stability up to 5% of compressive and 11% of tensile strain with significant phonon shifts. The phonon instability is shown to arise from the soft in-plane and out-of-plane acoustic modes at finite wave vector. The large strain tolerance of Janus MoSO is important for nanoelastic applications. In view of the dynamical stability even under moderate strain, we expect that Janus MoSO can be fabricated in the common 1H phase with a strong out-of-plane piezoelectric coefficient. |
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Wos |
000528507900003 |
Publication Date |
2020-04-24 |
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Series Editor |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.7 |
Times cited |
66 |
Open Access |
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Notes |
; Computational resources were provided by the Flemish Supercomputer Center (VSC). M.Y. is supported by the Flemish Science Foundation (FWO-Vl) through a postdoctoral fellowship. ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:169566 |
Serial |
6614 |
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Permanent link to this record |
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Author |
Zhao, X.N.; Xu, W.; Xiao, Y.M.; Liu, J.; Van Duppen, B.; Peeters, F.M. |
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Title |
Terahertz optical Hall effect in monolayer MoS₂ in the presence of proximity-induced interactions |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
101 |
Issue |
24 |
Pages |
245412-12 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The effect of proximity-induced interactions such as Rashba spin-orbit coupling (SOC) and exchange interaction on the electronic and optical properties of n-type monolayer (ML) MoS2 is investigated. We predict and demonstrate that the Rashba SOC can induce an in-plane spin splitting with terahertz (THz) energy, while the exchange interaction lifts the energy degeneracy in different valleys. Thus, spin polarization can be achieved in an n-type ML MoS2 and valley Hall or optical Hall effect can be observed using linearly polarized THz radiation. In such a case, the transverse optical conductivity sigma(xy) (omega) results from spin-flip transition within spin-split conduction bands and from the fact that contributions from electrons with different spin orientations in different valleys can no longer be canceled out. Interestingly, we find that for fixed effective Zeeman field (or exchange interaction) the lowest spin-split conduction band in ML MoS2 can be tuned from one in the K valley to another one in the K' valley by varying the Rashba parameter lambda(R). Therefore, by changing lambda(R) we can turn the sign of the spin polarization and Im sigma(xy) (omega) from positive to negative. Moreover, we find that the dominant contribution of the selection rules to sigma(xx)(omega) is from electrons in the K valley and to sigma(xy) (omega) is from electrons in the K' valley. These important and interesting theoretical findings can be helpful to experimental observation of the optical Hall effect in valleytronic systems using linearly polarized THz radiation fields. |
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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 |
000538715500011 |
Publication Date |
2020-06-09 |
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Series Editor |
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Series Title |
|
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 |
3.7 |
Times cited |
8 |
Open Access |
|
|
|
Notes |
; This work was supported by the National Natural Science Foundation of China (Grants No. U1930116, No. U1832153, and No. 11574319) and the Center of Science and Technology of Hefei Academy of Science (Grant No. 2016FXZY002). ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
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|
Call Number |
UA @ admin @ c:irua:170206 |
Serial |
6622 |
|
Permanent link to this record |
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Author |
Bafekry, A.; Neek-Amal, M. |
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Title |
Tuning the electronic properties of graphene-graphitic carbon nitride heterostructures and heterojunctions by using an electric field |
Type |
A1 Journal article |
|
Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
|
|
Volume |
101 |
Issue |
8 |
Pages |
085417-10 |
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|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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|
Abstract |
Integration of graphene-based two-dimensional materials is essential for nanoelectronics applications. Using density-functional theory, we systematically investigate the electronic properties of vertically stacked graphene-graphitic carbon nitrides (GE/GCN). We also studied the covalently lateral stitched graphene-graphitic carbon nitrides (GE-GCN heterojunctions). The effects of perpendicular electric field on the electronic properties of six different heterostructures, i.e., (i) one layer of GE on top of a layer of CnNm with (n, m) = (3,1), (3,4), and (4,3) and (ii) three heterostructures CnNm/Cn'Nm', where (n, m) not equal (n', m') are elucidated. The most important calculated features are (i) the systems GE/C3N4, C3N/C3N4, GE-C3N, GE-C4N3, and C3N-C3N4 exhibit semiconducting characteristics having small band gaps of Delta(0)=20, 250, 100, 100, 80 meV, respectively while (ii) the systems GE/C4N3, C3N/C4N3, and C3N-C4N3 show ferromagnetic-metallic properties. In particular, we found that, in semiconducting heterostructures, the band gap increases nontrivially with increasing the absolute value of the applied perpendicular electric field. This work is useful for designing heterojunctions and heterostructures made of graphene and other two-dimensional materials such as those proposed in recent experiments [X. Liu and M. C. Hersam Sci. Adv. 5, 6444 (2019)]. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000515659700007 |
Publication Date |
2020-02-26 |
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Series Editor |
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Series Title |
|
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 |
3.7 |
Times cited |
24 |
Open Access |
|
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|
Notes |
; ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:167760 |
Serial |
6640 |
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Permanent link to this record |
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Author |
Bafekry, A.; Neek-Amal, M.; Peeters, F.M. |
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Title |
Two-dimensional graphitic carbon nitrides: strain-tunable ferromagnetic ordering |
Type |
A1 Journal article |
|
Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
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|
Volume |
101 |
Issue |
16 |
Pages |
165407-165408 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Using first-principle calculations, we systematically study strain tuning of the electronic properties of two- dimensional graphitic carbon nitride nanosheets with empirical formula CnNm. We found the following: (i) the ferromagnetic ordered state in the metal-free systems (n, m) = (4,3), (10,9), and (14,12) remains stable in the presence of strain of about 6%. However, the system (9,7) loses its ferromagnetic ordering when increasing strain. This is due to the presence of topological defects in the (9,7) system, which eliminates the asymmetry between spin up and spin down of the p(z) orbitals when strain is applied. (ii) By applying uniaxial strain, a band gap opens in systems which are initially gapless. (iii) In semiconducting systems which have an initial gap of about 1 eV, the band gap is closed with applying uniaxial strain. |
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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 |
000523630200012 |
Publication Date |
2020-04-06 |
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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 |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.7 |
Times cited |
27 |
Open Access |
|
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Notes |
; ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:168560 |
Serial |
6643 |
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Permanent link to this record |
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Author |
Beames, A.; Broekx, S.; Heijungs, R.; Lookman, R.; Boonen, K.; Van Geert, Y.; Dendoncker, K.; Seuntjens, P. |
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Title |
Accounting for land-use efficiency and temporal variations between brownfield remediation alternatives in life-cycle assessment |
Type |
A1 Journal article |
|
Year |
2015 |
Publication |
Journal of cleaner production |
Abbreviated Journal |
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Volume |
101 |
Issue |
|
Pages |
109-117 |
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Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
The latest life-cycle assessment methods account for land use, due to the production, use and disposal of products and services, in terms of ecosystem damage. The process of brownfield remediation converts otherwise idle urban space into productive space. The value to ecosystems in this context is of course limited since the brownfield site remains urban. When evaluating brownfield remediation technologies, the availability of space on-site is dependent on the duration of time required by the remediation technology to reach the remediation target. Remediation technology alternatives tend to vary largely in terms of duration. Comparative life-cycle assessments of remediation technologies, to date, present the large variations between alternatives in terms of remediation duration but do not translate this into an impact or parameter. The restored subsurface zone is often defined as a functional unit, when in fact the surface area is the resource restored by the remediation service. The economic benefits of making land resources available are particularly important considerations in the context of brownfield remediation. The research proposes an innovative impact assessment approach that allows land to be considered as a finite resource. The method is applied in a comparative life-cycle assessment of two potential remediation scenarios for an idle brownfield in the Brussels region of Belgium. The results show that there is a trade-off between greenhouse gas emissions and land availability and that both are largely dependent on the efficiency of the contaminant extraction mechanism. The results also raise the question as to whether the economic valuation of land, like precious metals and fossil fuels, provides an accurate reflection of the true value of the resource. Considering land as a resource at the midpoint level is also relevant in other urban contexts where competition exists between different land-uses, where urban sprawl is detrimental to undeveloped areas and where urban intensification is a policy objective. (C) 2015 Elsevier Ltd. All rights reserved. |
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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 |
000356988200010 |
Publication Date |
2015-04-05 |
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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 |
0959-6526 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
|
Times cited |
|
Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:127010 |
Serial |
7412 |
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Permanent link to this record |
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Author |
Wozniak, T.; Faria, P.E., Jr.; Seifert, G.; Chaves, A.; Kunstmann, J. |
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Title |
Exciton g factors of van der Waals heterostructures from first-principles calculations |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
101 |
Issue |
23 |
Pages |
235408-235411 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
External fields are a powerful tool to probe optical excitations in a material. The linear energy shift of an excitation in a magnetic field is quantified by its effective g factor. Here we show how exciton g factors and their sign can be determined by converged first-principles calculations. We apply the method to monolayer excitons in semiconducting transition metal dichalcogenides and to interlayer excitons in MoSe2/WSe2 heterobilayers and obtain good agreement with recent experimental data. The precision of our method allows us to assign measured g factors of optical peaks to specific transitions in the band structure and also to specific regions of the samples. This revealed the nature of various, previously measured interlayer exciton peaks. We further show that, due to specific optical selection rules, g factors in van der Waals heterostructures are strongly spin and stacking-dependent. The calculation of orbital angular momenta requires the summation over hundreds of bands, indicating that for the considered two-dimensional materials the basis set size is a critical numerical issue. The presented approach can potentially be applied to a wide variety of semiconductors. |
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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 |
000537315100009 |
Publication Date |
2020-06-03 |
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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 |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.7 |
Times cited |
|
Open Access |
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Notes |
|
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:170219 |
Serial |
7944 |
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Permanent link to this record |
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Author |
Egoavil, R.; Tan, H.; Verbeeck, J.; Bals, S.; Smith, B.; Kuiper, B.; Rijnders, G.; Koster, G.; Van Tendeloo, G. |
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Title |
Atomic scale investigation of a PbTiO3/SrRuO3/DyScO3 heterostructure |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
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Volume |
102 |
Issue |
22 |
Pages |
223106-5 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
An epitaxial PbTiO3 thin film grown on self-organized crystalline SrRuO3 nanowires deposited on a DyScO3 substrate with ordered DyO and ScO2 chemical terminations is investigated by transmission electron microscopy. In this PbTiO3/SrRuO3/DyScO3 heterostructure, the SrRuO3 nanowires are assumed to grow on only one type of substrate termination. Here, we report on the structure, morphology, and chemical composition analysis of this heterostructure. Electron energy loss spectroscopy reveals the exact termination sequence in this complex structure. The energy loss near-edge structure of the Ti-L-2,L-3, Sc-L-2,L-3, and O K edges shows intrinsic interfacial electronic reconstruction. Furthermore, PbTiO3 domain walls are observed to start at the end of the nanowires resulting in atomic steps on the film surface. (C) 2013 AIP Publishing LLC. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000320621600070 |
Publication Date |
2013-06-05 |
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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 |
0003-6951; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
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Impact Factor |
3.411 |
Times cited |
12 |
Open Access |
|
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Notes |
Ifox; Esteem2; Countatoms; Vortex; esteem2jra3 ECASJO; |
Approved |
Most recent IF: 3.411; 2013 IF: 3.515 |
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Call Number |
UA @ lucian @ c:irua:109606UA @ admin @ c:irua:109606 |
Serial |
185 |
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Permanent link to this record |
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Author |
Zhao, C.X.; Xu, W.; Peeters, F.M. |
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Title |
Cerenkov emission of terahertz acoustic-phonons from graphene |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
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Volume |
102 |
Issue |
22 |
Pages |
222101-222104 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We present a theoretical study of the electrical generation of acoustic-phonon emission from graphene at room temperature. The drift velocity (v(x)) and temperature of electrons driven by dc electric field (F-x) are determined by solving self-consistently the momentum-and energy-balance equations derived from the Boltzmann equation. We find that in the presence of impurity, acoustic-and optic-phonon scattering, v(x) can be much larger than the longitudinal (v(l)) and transverse (v(t)) sound velocities in graphene even within the linear response regime. As a result, although the acoustic Cerenkov effect cannot be obviously seen in the analytical formulas, the enhanced acoustic-phonon emission can be observed with increasing F-x when v(x) > v(l) and v > v(t). The frequency of acoustic-phonon emission from graphene can be above 10 THz, which is much higher than that generated from conventional semiconductor systems. This study is pertinent to the application of graphene as hypersonic devices such as terahertz sound sources. (C) 2013 AIP Publishing LLC. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000320621600034 |
Publication Date |
2013-06-03 |
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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 |
|
Series Issue |
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Edition |
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ISSN |
0003-6951; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.411 |
Times cited |
25 |
Open Access |
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Notes |
; This work was supported by the National Natural Science Foundation of China (Grant No. 10974206), Ministry of Science and Technology of China (Grant No. 2011YQ130018), Department of Science and Technology of Yunnan Province, and by the Chinese Academy of Sciences. ; |
Approved |
Most recent IF: 3.411; 2013 IF: 3.515 |
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Call Number |
UA @ lucian @ c:irua:109607 |
Serial |
305 |
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Permanent link to this record |
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Author |
Payette, C.; Yu, G.; Gupta, J.A.; Austing, D.G.; Nair, S.V.; Partoens, B.; Amaha, S.; Tarucha, S. |
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Title |
Coherent three-level mixing in an electronic quantum dot |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
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Volume |
102 |
Issue |
2 |
Pages |
026808,1-026808,4 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We observe magnetic-field-induced level mixing and quantum superposition phenomena between three approaching single-particle states in a quantum dot probed via the ground state of an adjacent quantum dot by single-electron resonant tunneling. The mixing is attributed to anisotropy and anharmonicity in realistic dot confining potentials. The pronounced anticrossing and transfer of strengths (both enhancement and suppression) between resonances can be understood with a simple coherent level mixing model. Superposition can lead to the formation of a dark state by complete cancellation of an otherwise strong resonance, an effect resembling coherent population trapping in a three-level-system of quantum and atom optics. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000262535900060 |
Publication Date |
2009-01-16 |
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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 |
0031-9007;1079-7114; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
8.462 |
Times cited |
26 |
Open Access |
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Notes |
|
Approved |
Most recent IF: 8.462; 2009 IF: 7.328 |
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Call Number |
UA @ lucian @ c:irua:76019 |
Serial |
382 |
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Permanent link to this record |
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Author |
Frangis, N.; Van Tendeloo, G.; van Landuyt, J.; Muret, P.; Nguyen, T.T.A. |
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Title |
Electron microscopy characterisation of erbium silicide-thin films grown on a Si(111) substrate |
Type |
A1 Journal article |
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Year |
1996 |
Publication |
Applied surface science |
Abbreviated Journal |
Appl Surf Sci |
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Volume |
102 |
Issue |
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Pages |
163-168 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
A1996VJ86100037 |
Publication Date |
2003-05-12 |
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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 |
0169-4332; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
2.711 |
Times cited |
9 |
Open Access |
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Notes |
|
Approved |
no |
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Call Number |
UA @ lucian @ c:irua:15458 |
Serial |
953 |
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Permanent link to this record |
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Author |
Vandenberghe, W.G.; Verhulst, A.S.; Sorée, B.; Magnus, W.; Groeseneken, G.; Smets, Q.; Heyns, M.; Fischetti, M.V. |
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Title |
Figure of merit for and identification of sub-60 mV/decade devices |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
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Volume |
102 |
Issue |
1 |
Pages |
013510-13514 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
A figure of merit I60 is proposed for sub-60 mV/decade devices as the highest current where the input characteristics exhibit a transition from sub- to super-60 mV/decade behavior. For sub-60 mV/decade devices to be competitive with metal-oxide-semiconductor field-effect devices, I60 has to be in the 1-10 μA/μm range. The best experimental tunnel field-effect transistors (TFETs) in the literature only have an I60 of 6×10-3 μA/μm but using theoretical simulations, we show that an I60 of up to 10 μA/μm should be attainable. It is proven that the Schottky barrier FET (SBFET) has a 60 mV/decade subthreshold swing limit while combining a SBFET and a TFET does improve performance. |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000313646500132 |
Publication Date |
2013-01-12 |
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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 |
0003-6951; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
|
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Impact Factor |
3.411 |
Times cited |
64 |
Open Access |
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|
Notes |
; William G. Vandenberghe gratefully acknowledges the support of a Ph.D. stipend from IWT-Vlaanderen. The authors thank Danielle Leonelli, Lars-Ake Ragnarsson, and Krishna Bhuwalka for useful discussions. This work was supported by imec's Industrial Affiliation Program. ; |
Approved |
Most recent IF: 3.411; 2013 IF: 3.515 |
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Call Number |
UA @ lucian @ c:irua:109262 |
Serial |
1192 |
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Permanent link to this record |
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Author |
Kaltsas, G.; Travlos, A.; Nassiopoulos, A.G.; Frangis, N.; van Landuyt, J. |
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Title |
High crystalline quality erbium silicide films on (100) silicon grown in high vacuum |
Type |
A1 Journal article |
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Year |
1996 |
Publication |
Applied surface science |
Abbreviated Journal |
Appl Surf Sci |
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Volume |
102 |
Issue |
|
Pages |
151-155 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
A1996VJ86100034 |
Publication Date |
2003-05-12 |
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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 |
|
Series Issue |
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Edition |
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ISSN |
0169-4332; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.711 |
Times cited |
14 |
Open Access |
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Notes |
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Approved |
no |
|
|
Call Number |
UA @ lucian @ c:irua:15459 |
Serial |
1423 |
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Permanent link to this record |
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Author |
Amin-Ahmadi, B.; Idrissi, H.; Delmelle, R.; Pardoen, T.; Proost, J.; Schryvers, D. |
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Title |
High resolution transmission electron microscopy characterization of fcc -> 9R transformation in nanocrystalline palladium films due to hydriding |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
|
|
Volume |
102 |
Issue |
7 |
Pages |
071911-71914 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Sputtered nanocrystalline palladium thin films with nanoscale growth twins have been subjected to hydriding cycles. The evolution of the twin boundaries has been investigated using high resolution transmission electron microscopy. Surprisingly, the Sigma 3{112} incoherent twin boundaries dissociate after hydriding into two phase boundaries bounding a 9R phase. This phase which corresponds to single stacking faults located every three {111} planes in the fcc Pd structure was not expected because of the high stacking fault energy of Pd. This observation is connected to the influence of the Hydrogen on the stacking fault energy of palladium and the high compressive stresses building up during hydriding. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4793512] |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000315596700023 |
Publication Date |
2013-02-26 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0003-6951; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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|
Impact Factor |
3.411 |
Times cited |
14 |
Open Access |
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|
Notes |
Iap |
Approved |
Most recent IF: 3.411; 2013 IF: 3.515 |
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Call Number |
UA @ lucian @ c:irua:108303 |
Serial |
1462 |
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Permanent link to this record |
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Author |
Van Duppen, B.; Peeters, F.M. |
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Title |
Klein paradox for a pn junction in multilayer graphene |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
Europhysics letters |
Abbreviated Journal |
Epl-Europhys Lett |
|
|
Volume |
102 |
Issue |
2 |
Pages |
27001-27005 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Charge carriers in single and multilayered graphene systems behave as chiral particles due to the particular lattice symmetry of the crystal. We show that the interplay between the meta-material properties of graphene multilayers and the pseudospinorial properties of the charge carriers result in the occurrence of Klein and anti-Klein tunneling for rhombohedral stacked multilayers. We derive an algebraic formula predicting the angles at which these phenomena occur and support this with numerical calculations for systems up to four layers. We present a decomposition of an arbitrarily stacked multilayer into pseudospin doublets that have the same properties as rhombohedral systems with a lower number of layers. Copyright (C) EPLA, 2013 |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Paris |
Editor |
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Language |
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Wos |
000319617700017 |
Publication Date |
2013-05-02 |
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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 |
|
Series Issue |
|
Edition |
|
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|
ISSN |
0295-5075;1286-4854; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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|
Impact Factor |
1.957 |
Times cited |
17 |
Open Access |
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|
Notes |
; We thank S. GILLIS for valuable discussions. This work was supported by the European Science Foundation (ESF) under the EUROCORES Program Euro-GRAPHENE within the project CONGRAN, the Flemish Science Foundation (FWO-Vl) by an aspirant research grant to B. Van Duppen and the Methusalem Programme of the Flemish Government. ; |
Approved |
Most recent IF: 1.957; 2013 IF: 2.269 |
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Call Number |
UA @ lucian @ c:irua:109665 |
Serial |
1763 |
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Permanent link to this record |
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Author |
Liu, Y.; Brelet, Y.; He, Z.; Yu, L.; Forestier, B.; Deng, Y.; Jiang, H.; Houard, A. |
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Title |
Laser-induced periodic annular surface structures on fused silica surface |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
|
|
Volume |
102 |
Issue |
25 |
Pages |
251103-251104 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
We report on the formation of laser-induced periodic annular surface structures on fused silica irradiated with multiple femtosecond laser pulses. This surface morphology emerges after the disappearance of the conventional laser induced periodic surface structures, under successive laser pulse irradiation. It is independent of the laser polarization and universally observed for different focusing geometries. We interpret its formation in terms of the interference between the reflected laser field on the surface of the damage crater and the incident laser pulse. (C) 2013 AIP Publishing LLC. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000321145200003 |
Publication Date |
2013-06-24 |
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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 |
0003-6951; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.411 |
Times cited |
19 |
Open Access |
|
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|
Notes |
|
Approved |
Most recent IF: 3.411; 2013 IF: 3.515 |
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|
Call Number |
UA @ lucian @ c:irua:109832 |
Serial |
1786 |
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Permanent link to this record |
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Author |
Kalina, R.; Szafran, B.; Bednarek, S.; Peeters, F.M. |
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Title |
Magnetic-field asymmetry of electron wave packet transmission in bent channels capacitively coupled to a metal gate |
Type |
A1 Journal article |
|
Year |
2009 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
|
|
Volume |
102 |
Issue |
6 |
Pages |
066807,1-066807,4 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We study the electron wave packet moving through a bent channel. We demonstrate that the packet transmission probability becomes an asymmetric function of the magnetic field when the electron packet is capacitively coupled to a metal plate. The coupling occurs through a nonlinear potential which translates a different kinetics of the transport for opposite magnetic-field orientations into a different potential felt by the scattered electron. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000263389500056 |
Publication Date |
2009-02-12 |
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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 |
|
Series Issue |
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Edition |
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ISSN |
0031-9007;1079-7114; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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|
Impact Factor |
8.462 |
Times cited |
14 |
Open Access |
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|
Notes |
|
Approved |
Most recent IF: 8.462; 2009 IF: 7.328 |
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Call Number |
UA @ lucian @ c:irua:76315 |
Serial |
1867 |
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Permanent link to this record |
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Author |
He, Z.; Tian, H.; Deng, G.; Xu, Q.; Van Tendeloo, G. |
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Title |
Microstructure of bilayer manganite PrCa2Mn2O7 showing charge/orbital ordering |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
|
|
Volume |
102 |
Issue |
21 |
Pages |
212902-212905 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The microstructure of the charge/orbital ordering Ruddleden-Popper phase PrCa2Mn2O7 was studied by transmission electron microscopy along both the [001] and the [110] orientation. Three coexisting charge/orbital ordering phases CO1, CO2, and CO3 were observed along the [001] orientation at room temperature. Different from the one-dimensional modulation in the CO1 and CO2 phase, the CO3 phase is characterized by two sets of mutually perpendicular structural modulations. From [110] high angle annular dark field-scanning transmission electron microscopy, we found that the Pr atoms locate in-between the bilayer MnO6 octahedra, which is different from the previous reports. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000320620400056 |
Publication Date |
2013-05-29 |
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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 |
0003-6951; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.411 |
Times cited |
4 |
Open Access |
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Notes |
Countatoms |
Approved |
Most recent IF: 3.411; 2013 IF: 3.515 |
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Call Number |
UA @ lucian @ c:irua:108762 |
Serial |
2068 |
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Permanent link to this record |
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Author |
Shanenko, A.A.; Orlova, N.V.; Vagov, A.; Milošević, M.V.; Axt, V.M.; Peeters, F.M. |
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Title |
Nanofilms as quantum-engineered multiband superconductors : the Ginzburg-Landau theory |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Europhysics letters |
Abbreviated Journal |
Epl-Europhys Lett |
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|
Volume |
102 |
Issue |
2 |
Pages |
27003-27006 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Recently fabricated single-crystalline atomically flat metallic nanofilms are in fact quantum-engineered multiband superconductors. Here the multiband structure is dictated by the nanofilm thickness through the size quantization of the electron motion perpendicular to the nanofilm. This opens the unique possibility to explore superconductivity in well-controlled multi-band systems. However, a serious obstacle is the absence of a convenient and manageable theoretical tool to access new physical phenomena in such quasi-two-dimensional systems, including interplay of quantum confinement and fluctuations. Here we cover this gap and construct the appropriate multiband Ginzburg-Landau functional for nano-thin superconductors. Copyright (C) EPLA, 2013 |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Paris |
Editor |
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Language |
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Wos |
000319617700019 |
Publication Date |
2013-05-03 |
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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 |
|
Edition |
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ISSN |
0295-5075;1286-4854; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
1.957 |
Times cited |
8 |
Open Access |
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|
Notes |
; This work was supported by the “Odysseus” Program of the Flemish Government and the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 1.957; 2013 IF: 2.269 |
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Call Number |
UA @ lucian @ c:irua:109859 |
Serial |
2257 |
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Permanent link to this record |
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Author |
Muret, P.; Nguyen, T.T.A.; Frangis, N.; Van Tendeloo, G.; van Landuyt, J. |
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Title |
Photoelectric and electrical responses of several erbium silicide/silicon interfaces |
Type |
A1 Journal article |
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Year |
1996 |
Publication |
Applied surface science
T2 – International Symposium on Si Heterostructures – From Physics to Devices, SEP 11-14, 1995, IRAKLION, GREECE |
Abbreviated Journal |
Appl Surf Sci |
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Volume |
102 |
Issue |
|
Pages |
173-177 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
In this work, photoelectric yield and electrical properties of several types of epitaxial erbium silicide on silicon Schottky diodes are studied, Different preparation conditions are used simultaneously on n- and p-Si(111) substrates for the 200 Angstrom thick silicide films. A last type of sample consists in 1.3 monolayer of epitaxial silicide with root 3 X root 3 superstructure on the Si substrate and covered by silver on the top. Photocurrent measurements are done as a function of photon energy at several temperatures. All these samples show barrier heights near 1 eV on p-type Si, even for the interface comprising only 1.3 monolayer of silicide whereas barrier heights on n-rype Si span the range from 0.28 to 0.67 eV for this last kind of sample, the sum of the barriers always exceeding the silicon band gap, These photoelectric results are confirmed by electrical characterisations, All these results show that the Fermi level is pinned 0.1 eV below the conduction band edge on p-type Si but shifts to various positions lower within the band gap on n-type Si. This fact leads to the hypothesis of a density of -7 interface states close to the charge change in the Si depletion zone from p- to n-type, namely 10(12) eV(-1) cm(-2). Although some inhomogeneities and defects at the interface are detected by electron microscopy for samples annealed at 750 degrees C, Fermi level position seems rather insensitive to the structural details of the interface while the silicide thickness plays a role on n-type Si. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
A1996VJ86100039 |
Publication Date |
2003-05-12 |
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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 |
0169-4332; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.711 |
Times cited |
3 |
Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ lucian @ c:irua:104392 |
Serial |
2611 |
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Permanent link to this record |
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Author |
Verbeeck, J.; van Dyck, D.; Lichte, H.; Potapov, P.; Schattschneider, P. |
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Title |
Plasmon holographic experiments: theoretical framework |
Type |
A1 Journal article |
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Year |
2005 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
102 |
Issue |
3 |
Pages |
239-255 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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Abstract |
A theoretical framework is described to understand the results of plasmon holography experiments leading to insight in the meaning of the experimental results and pointing out directions for future experiments. The framework is based on the formalism of mutual intensity to describe how coherence is transferred through an optical system. For the inelastic interaction with the object, an expression for the volume. plasmon excitations in a free electron gas is used as a model for the behaviour of aluminium. The formalism leads to a clear graphical intuitive tool for under-standing the experiments. It becomes evident that the measured coherence is solely related to the angular distribution of the plasmon scattering in the case of bulk plasmons. After describing the framework, the special case of coherence outside a spherical particle is treated and the seemingly controversial idea of a plasmon with a limited coherence length obtained front experiments is clarified. (C) 2004 Elsevier B.V. All rights reserved. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000226436600010 |
Publication Date |
2004-11-05 |
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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 |
|
Series Issue |
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Edition |
|
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ISSN |
0304-3991; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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|
Impact Factor |
2.843 |
Times cited |
43 |
Open Access |
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Notes |
Fwo |
Approved |
Most recent IF: 2.843; 2005 IF: 2.490 |
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Call Number |
UA @ lucian @ c:irua:57133UA @ admin @ c:irua:57133 |
Serial |
2643 |
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Permanent link to this record |
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Author |
Tang, Y.; Chen, Z.; Borbely, A.; Ji, G.; Zhong, S.Y.; Schryvers, D.; Ji, V.; Wang, H.W. |
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Title |
Quantitative study of particle size distribution in an in-situ grown Al-TiB2 composite by synchrotron X-ray diffraction and electron microscopy |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Materials characterization |
Abbreviated Journal |
Mater Charact |
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Volume |
102 |
Issue |
102 |
Pages |
131-136 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Synchrotron X-ray diffraction and transmission electron microscopy (TEM) were applied to quantitatively characterize the average particle size and size distribution of free-standing TiB2 particles and TiB2 particles in an insitu grown Al–TiB2 composite. The detailed evaluations were carried out by X-ray line profile analysis using the restrictedmoment method and multiplewhole profile fitting procedure (MWP). Both numericalmethods indicate that the formed TiB2 particles are well crystallized and free of crystal defects. The average particle size determined from different Bragg reflections by the restricted moment method ranges between 25 and 55 nm, where the smallest particle size is determined using the 110 reflection suggesting the highest lateral-growth velocity of (110) facets. TheMWP method has shown that the in-situ grown TiB2 particles have a very low dislocation density (~1011 m−2) and their size distribution can be described by a log-normal distribution. Good agreement was found between the results obtained from the restricted moment and MWP methods, which was further confirmed by TEM. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
New York |
Editor |
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Language |
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Wos |
000355335200017 |
Publication Date |
2015-03-04 |
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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 |
|
Series Issue |
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Edition |
|
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ISSN |
1044-5803; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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|
Impact Factor |
2.714 |
Times cited |
41 |
Open Access |
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|
Notes |
This work is financially supported by the National Natural Science Foundation of China (Grant No. 51201099 and No. 51301108) and the China Postdoctoral Science Foundation (Grant No. 2013T60443 and No. 2012M520891). The authors are grateful for the project 2013BB03 supported by NPL, CAEP. Many thanks are also due to the faculty of BL14B beamline at the Shanghai Synchrotron Radiation Facility for their help on synchrotron experiments. |
Approved |
Most recent IF: 2.714; 2015 IF: 1.845 |
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Call Number |
c:irua:126443 |
Serial |
2764 |
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Permanent link to this record |
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Author |
De Meulenaere, P.; Mommaert, C.; Van Tendeloo, G. |
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Title |
Short-range order in phase segregation systems |
Type |
A1 Journal article |
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Year |
1997 |
Publication |
Solid state communications |
Abbreviated Journal |
Solid State Commun |
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Volume |
102 |
Issue |
9 |
Pages |
687-690 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Spin systems on an f.c.c.-lattice which exhibit phase segregation are studied by means of Monte Carlo simulations. Short-range order, both above and below the segregation temperature, is observed. Experimental evidence for short range order in Ti-V is provided by electron diffraction. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
A1997WX40300011 |
Publication Date |
2003-05-13 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0038-1098; |
ISBN |
|
Additional Links |
UA library record; WoS full record |
|
|
Impact Factor |
1.554 |
Times cited |
|
Open Access |
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Notes |
|
Approved |
Most recent IF: 1.554; 1997 IF: 1.323 |
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Call Number |
UA @ lucian @ c:irua:21429 |
Serial |
2997 |
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Permanent link to this record |