| |
Records |
Links |
|
Author |
Carrillo-Nuñez, H.; Magnus, W.; Peeters, F.M. |
|
| |
Title |
A simplified quantum mechanical model for nanowire transistors based on non-linear variational calculus |
Type |
A1 Journal article |
| |
Year |
2010 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
|
| |
Volume |
108 |
Issue  |
6 |
Pages |
063708,1-063708,8 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
A simplified quantum mechanical model is developed to investigate quantum transport features such as the electron concentration and the current flowing through a silicon nanowire metal-oxide-semiconductor field-effect transistor (MOSFET). In particular, the electron concentration is extracted from a self-consistent solution of the Schrödinger and Poisson equations as well as the ballistic Boltzmann equation which have been solved by exploiting a nonlinear variational principle within the framework of the generalized local density approximation. A suitable action functional has been minimized and details of the implementation and its numerical minimization are given. The current density and its related current-voltage characteristics are calculated from the one-dimensional ballistic steady-state Boltzmann transport equation which is solved analytically by using the method of characteristic curves. The straightforward implementation, the computational speed and the good qualitative behavior of the transport characteristics observed in our approach make it a promising simulation method for modeling quantum transport in nanowire MOSFETs. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
|
| |
Language |
|
Wos |
000282646400067 |
Publication Date |
2010-09-22 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0021-8979; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.068 |
Times cited |
7 |
Open Access |
|
|
| |
Notes |
; This work was supported by Flemish Science Foundation (FWO-VI) and the Interuniversity Attraction Poles, Belgium State, Belgium Science Policy, and IMEC. ; |
Approved |
Most recent IF: 2.068; 2010 IF: 2.079 |
|
| |
Call Number |
UA @ lucian @ c:irua:84943 |
Serial |
3006 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Vansweevelt, R.; Mortet, V.; D' Haen, J.; Ruttens, bart; van Haesendonck, C.; Partoens, B.; Peeters, F.M.; Wagner, P. |
|
| |
Title |
Study on the giant positive magnetoresistance and Hall effect in ultrathin graphite flakes |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Physica status solidi : A : applications and materials science |
Abbreviated Journal |
Phys Status Solidi A |
|
| |
Volume |
208 |
Issue |
6 |
Pages |
1252-1258 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
In this paper, we report on the electronic transport properties of mesoscopic, ultrathin graphite flakes with a thickness corresponding to a stack of 150 graphene layers. The graphite flakes show an unexpectedly strong positive magnetoresistance (PMR) already at room temperature, which scales in good approximation with the square of the magnetic field. Furthermore, we show that the resistivity is unaffected by magnetic fields oriented in plane with the graphene layers. Hall effect measurements indicate that the charge carriers are p-type and their concentration increases with increasing temperature while the mobility is decreasing. The Hall voltage is non-linear in higher magnetic fields. Possible origins of the observed effects are discussed. Ball and stick model of the two topmost carbon layers of the hexagonal graphite structure. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000292945800008 |
Publication Date |
2011-02-24 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1862-6300; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
1.775 |
Times cited |
8 |
Open Access |
|
|
| |
Notes |
; The authors gratefully acknowledge the support by FWO – Research Foundation Flanders (project G.0159.07 “Structural and electronic properties of biologically modified, graphene-based layers”), by the Federal Belgian Interuniversity Attraction Poles Programme BELSPO (project TAP VI P6/42 “Quantum effects in clusters and nanowires”) and by the Methusalem network “NANO – Antwerp-Hasselt,” funded by the Flemish Community. Technical assistance by Stoffel D. Janssens (magnet calibration and software development), Dr. Hong Yin (AFM-based thickness studies), Dr. Ronald Thoelen (data analysis), and Prof. Hans-Gerd Boyen (XPS spectroscopy) is greatly appreciated. ; |
Approved |
Most recent IF: 1.775; 2011 IF: 1.463 |
|
| |
Call Number |
UA @ lucian @ c:irua:91941 |
Serial |
3343 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Nikolaev, A.V.; Michel, K.H. |
|
| |
Title |
Superexchange and electron correlations in alkali fullerides AC60, A=K, Rb, Cs |
Type |
A1 Journal article |
| |
Year |
2005 |
Publication |
The journal of chemical physics |
Abbreviated Journal |
J Chem Phys |
|
| |
Volume |
122 |
Issue |
6 |
Pages |
064310-64314 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Superexchange interactions in alkali fullerides AC(60) are derived for C-60 molecular ions separated by interstitial alkali-metal ions. We use a multiconfiguration approach which comprises the lowest molecular orbital states of the C-60 molecule and the excited s and d states of the alkali-metal atom A. Interactions are described by the valence bond (Heitler-London) method for a complex (C-60 – A – C-60) – with two valence electrons. The electronic charge transfer between the alkali-metal atom and a neighboring C-60 molecule is not complete. The occupation probability of excited d and s states of the alkali atom is not negligible. In correspondence with the relative positions of the C-60 molecules and A atoms in the polymer crystal, we consider 180degrees and 90degrees (angle) superexchange pathways. For the former case the ground state is found to be a spin singlet separated from a triplet at similar to20 K. For T < 20 K there appear strong spin correlations for the 180degrees superexchange pathway. The results are related to spin lattice relaxation experiments on CsC60 in the polymerized and in the quenched cubic phase. (C) 2005 American Institute of Physics. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
|
| |
Language |
|
Wos |
000226918100018 |
Publication Date |
2005-02-02 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0021-9606; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.965 |
Times cited |
11 |
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 2.965; 2005 IF: 3.138 |
|
| |
Call Number |
UA @ lucian @ c:irua:102740 |
Serial |
3377 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Michel, K.H.; Verberck, B.; Hulman, M.; Kuzmany, H.; Krause, M. |
|
| |
Title |
Superposition of quantum and classical rotational motions in Sc2C2@C84 fullerite |
Type |
A1 Journal article |
| |
Year |
2007 |
Publication |
The journal of chemical physics |
Abbreviated Journal |
J Chem Phys |
|
| |
Volume |
126 |
Issue |
6 |
Pages |
064304,1-15 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
|
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
|
| |
Language |
|
Wos |
000244250200008 |
Publication Date |
2007-02-09 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0021-9606; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.965 |
Times cited |
14 |
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 2.965; 2007 IF: 3.044 |
|
| |
Call Number |
UA @ lucian @ c:irua:63628 |
Serial |
3381 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Payette, C.; Austing, D.G.; Yu, G.; Gupta, J.A.; Nair, S.V.; Partoens, B.; Amaha, S.; Tarucha, S. |
|
| |
Title |
Two-level anti-crossings high up in the single-particle energy spectrum of a quantum dot |
Type |
A1 Journal article |
| |
Year |
2008 |
Publication |
Physica. E: Low-dimensional systems and nanostructures |
Abbreviated Journal |
Physica E |
|
| |
Volume |
40 |
Issue |
6 |
Pages |
1807-1810 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
|
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000255717400010 |
Publication Date |
2007-09-22 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1386-9477; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.221 |
Times cited |
8 |
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 2.221; 2008 IF: 1.230 |
|
| |
Call Number |
UA @ lucian @ c:irua:69132 |
Serial |
3783 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Bothner, D.; Seidl, R.; Misko, V.R.; Kleiner, R.; Koelle, D.; Kemmler, M. |
|
| |
Title |
Unusual commensurability effects in quasiperiodic pinning arrays induced by local inhomogeneities of the pinning site density |
Type |
A1 Journal article |
| |
Year |
2014 |
Publication |
Superconductor science and technology |
Abbreviated Journal |
Supercond Sci Tech |
|
| |
Volume |
27 |
Issue |
6 |
Pages |
065002 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
We experimentally investigate the magnetic field dependence of the critical current I-c(B) of superconducting niobium thin films patterned with periodic and quasiperiodic antidot arrays on the submicron scale. For this purpose we monitor current-voltage characteristics at different values of B and temperature T. We investigate samples with antidots positioned at the vertices of two different tilings with quasiperiodic symmetry, namely the Shield Tiling and the Tuebingen Triangle Tiling. For reference we investigate a sample with a triangular antidot lattice. We find modulations of the critical current for both quasiperiodic tilings, which have partly been predicted by numerical simulations but not observed in experiments yet. The particularity of these commensurability effects is that they correspond to magnetic field values slightly above an integer multiple of the matching field. The observed matching effects can be explained by the caging of interstitial vortices in quasiperiodically distributed cages and the formation of symmetry-induced giant vortices. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
Bristol |
Editor |
|
|
| |
Language |
|
Wos |
000336494900003 |
Publication Date |
2014-04-03 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0953-2048;1361-6668; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.878 |
Times cited |
7 |
Open Access |
|
|
| |
Notes |
; This work has been supported by the European Research Council via SOCATHES and by the Deutsche Forschungsgemeinschaft via the SFB/TRR 21. DB gratefully acknowledges support by the Evangelisches Studienwerk e.V. Villigst. MK gratefully acknowledges support by the Carl-Zeiss Stiftung. VRM gratefully acknowledges support by the 'Odysseus' Program of the Flemish Government and the Flemish Science Foundation (FWO-VI). The authors thank Franco Nori for fruitful discussions on quasiperiodic pinning arrays. ; |
Approved |
Most recent IF: 2.878; 2014 IF: 2.325 |
|
| |
Call Number |
UA @ lucian @ c:irua:117763 |
Serial |
3817 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Sarmadian, N.; Saniz, R.; Partoens, B.; Lamoen, D. |
|
| |
Title |
Easily doped p-type, low hole effective mass, transparent oxides |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Scientific reports |
Abbreviated Journal |
Sci Rep-Uk |
|
| |
Volume |
6 |
Issue |
6 |
Pages |
20446 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
|
| |
Abstract |
Fulfillment of the promise of transparent electronics has been hindered until now largely by the lack of semiconductors that can be doped p-type in a stable way, and that at the same time present high hole mobility and are highly transparent in the visible spectrum. Here, a high-throughput study based on first-principles methods reveals four oxides, namely X2SeO2, with X = La, Pr, Nd, and Gd, which are unique in that they exhibit excellent characteristics for transparent electronic device applications – i.e., a direct band gap larger than 3.1 eV, an average hole effective mass below the electron rest mass, and good p-type dopability. Furthermore, for La2SeO2 it is explicitly shown that Na impurities substituting La are shallow acceptors in moderate to strong anion-rich growth conditions, with low formation energy, and that they will not be compensated by anion vacancies VO or VSe. |
|
| |
Address |
EMAT, Departement Fysica, Universiteit Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen, Belgium |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Wos |
000369568900001 |
Publication Date |
2016-02-08 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2045-2322 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.259 |
Times cited |
55 |
Open Access |
|
|
| |
Notes |
We acknowledge the financial support of FWO-Vlaanderen through project G.0150.13 and of a GOA fund from the University of Antwerp. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the Hercules Foundation and the Flemish Government–department EWI. |
Approved |
Most recent IF: 4.259 |
|
| |
Call Number |
c:irua:131611 |
Serial |
4036 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Sahin, H.; Torun, E.; Bacaksiz, C.; Horzum, S.; Kang, J.; Senger, R.T.; Peeters, F.M. |
|
| |
Title |
Computing optical properties of ultra-thin crystals |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Wiley Interdisciplinary Reviews: Computational Molecular Science |
Abbreviated Journal |
Wires Comput Mol Sci |
|
| |
Volume |
6 |
Issue |
6 |
Pages |
351-368 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
An overview is given of recent advances in experimental and theoretical understanding of optical properties of ultra-thin crystal structures (graphene, phosphorene, silicene, MoS2 , MoSe2, WS2, WSe2, h-AlN, h-BN, fluorographene, and graphane). Ultra-thin crystals are atomically thick-layered crystals that have unique properties which differ from their 3D counterpart. Because of the difficulties in the synthesis of few-atom-thick crystal structures, which are thought to be the main building blocks of future nanotechnology, reliable theoretical predictions of their electronic, vibrational, and optical properties are of great importance. Recent studies revealed the reliable predictive power of existing theoretical approaches based on density functional theory. (C) 2016 John Wiley & Sons, Ltd WIREs Comput Mol Sci 2016, 6:351-368. doi: 10.1002/wcms.1252 For further resources related to this article, please visit the . |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000379267300002 |
Publication Date |
2016-02-20 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1759-0876 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
14.016 |
Times cited |
14 |
Open Access |
|
|
| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem Foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H.S. is supported by a FWO Pegasus Long Marie Curie Fellowship. J.K. is supported by a FWO Pegasus short Marie Curie Fellowship. ; |
Approved |
Most recent IF: 14.016 |
|
| |
Call Number |
UA @ lucian @ c:irua:134649 |
Serial |
4155 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Buh, J.; Kabanov, V.; Baranov, V.; Mrzel, A.; Kovic, A.; Mihailovic, D. |
|
| |
Title |
Control of switching between metastable superconducting states in delta-MoN nanowires |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
|
| |
Volume |
6 |
Issue |
6 |
Pages |
10250 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
|
| |
Abstract |
The superconducting state in one-dimensional nanosystems is very delicate. While fluctuations of the phase of the superconducting wave function lead to the spontaneous decay of persistent supercurrents in thin superconducting wires and nanocircuits, discrete phase-slip fluctuations can also lead to more exotic phenomena, such as the appearance of metastable superconducting states in current-bearing wires. Here we show that switching between different metastable superconducting states in d-MoN nanowires can be very effectively manipulated by introducing small amplitude electrical noise. Furthermore, we show that deterministic switching between metastable superconducting states with different numbers of phase-slip centres can be achieved in both directions with small electrical current pulse perturbations of appropriate polarity. The observed current-controlled bi-stability is in remarkable agreement with theoretically predicted trajectories of the system switching between different limit cycle solutions of a model one-dimensional superconductor. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000367576600002 |
Publication Date |
2015-12-21 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
12.124 |
Times cited |
8 |
Open Access |
|
|
| |
Notes |
; ; |
Approved |
Most recent IF: 12.124; 2015 IF: 11.470 |
|
| |
Call Number |
UA @ lucian @ c:irua:131108 |
Serial |
4156 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Zarenia, M.; Perali, A.; Peeters, F.M.; Neilson, D. |
|
| |
Title |
Large gap electron-hole superfluidity and shape resonances in coupled graphene nanoribbons |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Scientific reports |
Abbreviated Journal |
Sci Rep-Uk |
|
| |
Volume |
6 |
Issue |
6 |
Pages |
24860 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
|
| |
Abstract |
We predict enhanced electron-hole superfluidity in two coupled electron-hole armchair-edge terminated graphene nanoribbons separated by a thin insulating barrier. In contrast to graphene monolayers, the multiple subbands of the nanoribbons are parabolic at low energy with a gap between the conduction and valence bands, and with lifted valley degeneracy. These properties make screening of the electron-hole interaction much weaker than for coupled electron-hole monolayers, thus boosting the pairing strength and enhancing the superfluid properties. The pairing strength is further boosted by the quasi one-dimensional quantum confinement of the carriers, as well as by the large density of states near the bottom of each subband. The latter magnifies superfluid shape resonances caused by the quantum confinement. Several superfluid partial condensates are present for finite-width nanoribbons with multiple subbands. We find that superfluidity is predominately in the strongly-coupled BEC and BCS-BEC crossover regimes, with large superfluid gaps up to 100 meV and beyond. When the gaps exceed the subband spacing, there is significant mixing of the subbands, a rounding of the shape resonances, and a resulting reduction in the one-dimensional nature of the system. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Nature Publishing Group |
Place of Publication |
London |
Editor |
|
|
| |
Language |
|
Wos |
000374654500002 |
Publication Date |
2016-04-25 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2045-2322 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.259 |
Times cited |
7 |
Open Access |
|
|
| |
Notes |
; M.Z. acknowledges support by the Flemish Science Foundation (FWO-Vl), the University Research Fund (BOF), and the European Science Foundation (POLATOM). A.P. and D.N. acknowledge support by the University of Camerino FAR project CESEMN. The authors thank the colleagues involved in the MultiSuper International Network (http://www.multisuper.org) for exchange of ideas and suggestions for this work. ; |
Approved |
Most recent IF: 4.259 |
|
| |
Call Number |
UA @ lucian @ c:irua:133619 |
Serial |
4201 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Schouteden, K.; Li, Z.; Chen, T.; Song, F.; Partoens, B.; Van Haesendonck, C.; Park, K. |
|
| |
Title |
Moire superlattices at the topological insulator Bi2Te3 |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Scientific reports |
Abbreviated Journal |
Sci Rep-Uk |
|
| |
Volume |
6 |
Issue |
6 |
Pages |
20278 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
|
| |
Abstract |
We report on the observation of complex superlattices at the surface of the topological insulator Bi2Te3. Scanning tunneling microscopy reveals the existence of two different periodic structures in addition to the Bi2Te3 atomic lattice, which is found to strongly affect the local electronic structure. These three different periodicities are interpreted to result from a single small in-plane rotation of the topmost quintuple layer only. Density functional theory calculations support the observed increase in the DOS near the Fermi level, and exclude the possibility that strain is at the origin of the observed Moire pattern. Exploration of Moire superlattices formed by the quintuple layers of topological insulators holds great potential for further tuning of the properties of topological insulators. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Nature Publishing Group |
Place of Publication |
London |
Editor |
|
|
| |
Language |
|
Wos |
000369543200001 |
Publication Date |
2016-02-08 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2045-2322 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.259 |
Times cited |
14 |
Open Access |
|
|
| |
Notes |
; The research in Leuven and Antwerp has been supported by the Research Foundation – Flanders (FWO, Belgium). The research in Leuven received additional support from the Flemish Concerted Research Action program (BOF KU Leuven, Project No. GOA/14/007). Z.L. thanks the China Scholarship Council for financial support (No. 2011624021). K.S. acknowledges support from the FWO. K.P. was supported by U.S. National Science Foundation DMR-1206354 and San Diego Supercomputer Center (SDSC) Trestles under DMR060009N. T.C. and F.S. acknowledge the financial support of the National Key Projects for Basic Research of China (Grant Nos: 2013CB922103), the National Natural Science Foundation of China (Grant Nos: 91421109, 11522432), the PAPD project, and the Natural Science Foundation of Jiangsu Province (Grant BK20130054). ; |
Approved |
Most recent IF: 4.259 |
|
| |
Call Number |
UA @ lucian @ c:irua:131612 |
Serial |
4208 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Suslu, A.; Wu, K.; Sahin, H.; Chen, B.; Yang, S.; Cai, H.; Aoki, T.; Horzum, S.; Kang, J.; Peeters, F.M.; Tongay, S.; |
|
| |
Title |
Unusual dimensionality effects and surface charge density in 2D Mg(OH)2 |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Scientific reports |
Abbreviated Journal |
Sci Rep-Uk |
|
| |
Volume |
6 |
Issue |
6 |
Pages |
20525 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
|
| |
Abstract |
We present two-dimensional Mg(OH)(2) sheets and their vertical heterojunctions with CVD-MoS2 for the first time as flexible 2D insulators with anomalous lattice vibration and chemical and physical properties. New hydrothermal crystal growth technique enabled isolation of environmentally stable monolayer Mg(OH)(2) sheets. Raman spectroscopy and vibrational calculations reveal that the lattice vibrations of Mg(OH)(2) have fundamentally different signature peaks and dimensionality effects compared to other 2D material systems known to date. Sub-wavelength electron energy-loss spectroscopy measurements and theoretical calculations show that Mg(OH)(2) is a 6 eV direct-gap insulator in 2D, and its optical band gap displays strong band renormalization effects from monolayer to bulk, marking the first experimental confirmation of confinement effects in 2D insulators. Interestingly, 2D-Mg(OH)(2) sheets possess rather strong surface polarization (charge) effects which is in contrast to electrically neutral h-BN materials. Using 2D-Mg(OH)(2) sheets together with CVD-MoS2 in the vertical stacking shows that a strong change transfer occurs from n-doped CVD-MoS2 sheets to Mg(OH)(2), naturally depleting the semiconductor, pushing towards intrinsic doping limit and enhancing overall optical performance of 2D semiconductors. Results not only establish unusual confinement effects in 2D-Mg(OH)(2), but also offer novel 2D-insulating material with unique physical, vibrational, and chemical properties for potential applications in flexible optoelectronics. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Nature Publishing Group |
Place of Publication |
London |
Editor |
|
|
| |
Language |
|
Wos |
000369510300001 |
Publication Date |
2016-02-05 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2045-2322 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.259 |
Times cited |
39 |
Open Access |
|
|
| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). HS is supported by a FWO Pegasus Long Marie Curie Fellowship. JK is supported by a FWO Pegasus-short Marie Curie Fellowship. We acknowledge the use of John M. Cowley Center for High Resolution Electron Microscopy at Arizona State University. ; |
Approved |
Most recent IF: 4.259 |
|
| |
Call Number |
UA @ lucian @ c:irua:131615 |
Serial |
4272 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Yang, W.; Misko, V.R.; Tempère, J.; Kong, M.; Peeters, F.M. |
|
| |
Title |
Artificial living crystals in confined environment |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Physical Review E |
Abbreviated Journal |
Phys Rev E |
|
| |
Volume |
95 |
Issue |
6 |
Pages |
062602 |
|
| |
Keywords |
A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Similar to the spontaneous formation of colonies of bacteria, flocks of birds, or schools of fish, “living crystals” can be formed by artificial self-propelled particles such as Janus colloids. Unlike usual solids, these “crystals” are far from thermodynamic equilibrium. They fluctuate in time forming a crystalline structure, breaking apart and re-forming again. We propose a method to stabilize living crystals by applying a weak confinement potential that does not suppress the ability of the particles to perform self-propelled motion, but it stabilizes the structure and shape of the dynamical clusters. This gives rise to such configurations of living crystals as “living shells” formed by Janus colloids. Moreover, the shape of the stable living clusters can be controlled by tuning the potential strength. Our proposal can be verified experimentally with either artificial microswimmers such as Janus colloids, or with living active matter. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000402667600006 |
Publication Date |
2017-06-06 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2470-0045;2470-0053; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.366 |
Times cited |
10 |
Open Access |
|
|
| |
Notes |
; This work was supported by the “Odysseus” Program of the Flemish Government and the Flemish Research Foundation (FWO-Vl) (Belgium), the Flemish Research Foundation (through Projects No. G.0115.12N, No. G.0119.12N, No. G.0122.12N, and No. G.0429.15N), and the Research Fund of the University of Antwerp. W.Y. acknowledges the support from the National Natural Science Foundation of China under Grants No. 11204199 and No. 51135007, the China Scholarship Council, the 131 project and the Program for the Outstanding Innovative Teams of Higher Learning Institutions of Shanxi, and a project under Grant No. 2016-096 by Shanxi Scholarship Council of China. ; |
Approved |
Most recent IF: 2.366 |
|
| |
Call Number |
UA @ lucian @ c:irua:144205 |
Serial |
4641 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Zebrowski, D.P.; Peeters, F.M.; Szafran, B. |
|
| |
Title |
Driven spin transitions in fluorinated single- and bilayer-graphene quantum dots |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Semiconductor science and technology |
Abbreviated Journal |
Semicond Sci Tech |
|
| |
Volume |
32 |
Issue |
6 |
Pages |
065016 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Spin transitions driven by a periodically varying electric potential in dilute fluorinated graphene quantum dots are investigated. Flakes of monolayer graphene as well as electrostatic electron traps induced in bilayer graphene are considered. The stationary states obtained within the tight-binding approach are used as the basis for description of the system dynamics. The dilute fluorination of the top layer lifts the valley degeneracy of the confined states and attenuates the orbital magnetic dipole moments due to current circulation within the flake. The spin-orbit coupling introduced by the surface deformation of the top layer induced by the adatoms allows the spin flips to be driven by the AC electric field. For the bilayer quantum dots the spin flip times is substantially shorter than the spin relaxation. Dynamical effects including many-photon and multilevel transitions are also discussed. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
London |
Editor |
|
|
| |
Language |
|
Wos |
000402405800007 |
Publication Date |
2017-04-19 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0268-1242 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
|
| |
Impact Factor |
2.305 |
Times cited |
|
Open Access |
|
|
| |
Notes |
; This work was supported by the National Science Centre according to decision DEC-2013/11/B/ST3/03837 and by the Flemish Science Foundation (FWO-VL). ; |
Approved |
Most recent IF: 2.305 |
|
| |
Call Number |
UA @ lucian @ c:irua:144238 |
Serial |
4646 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Ghorbanfekr-Kalashami, H.; Peeters, F.M.; Novoselov, K.S.; Neek-Amal, M. |
|
| |
Title |
Spatial design and control of graphene flake motion |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
| |
Volume |
96 |
Issue |
6 |
Pages |
060101 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
|
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
|
|
| |
Language |
|
Wos |
000406860300001 |
Publication Date |
2017-08-04 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.836 |
Times cited |
3 |
Open Access |
|
|
| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem program. M.N.-A. was supported by Iran National Science Foundation (INSF). K.S.N. was supported by the EU Graphene Flagship Program, European Research Council Synergy Grant Hetero2D, the Royal Society, Engineering and Physical Research Council (UK), US Army Research Office. ; |
Approved |
Most recent IF: 3.836 |
|
| |
Call Number |
UA @ lucian @ c:irua:145166 |
Serial |
4724 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Wang, W.; Van Duppen, B.; Van der Donck, M.; Peeters, F.M. |
|
| |
Title |
Magnetopolaron effect on shallow-impurity states in the presence of magnetic and intense terahertz laser fields in the Faraday configuration |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
| |
Volume |
97 |
Issue |
6 |
Pages |
064108 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
The magnetopolaron effect on shallow-impurity states in semiconductors is investigated when subjected simultaneously to a magnetic field and an intense terahertz laser field within the Faraday configuration. We use a time-dependent nonperturbative theory to describe electron interactions. The externally applied fields are exactly included via a laser-dressed interaction potential. Through a variational approach we evaluate the binding energy of the shallow-impurity states. We find that the interaction strength of the laser-dressed Coulomb potential can not only be enhanced but also weakened by varying the two external fields. In this way, the binding energy can be tuned by the external fields and red-or blue-shifted with respect to the static binding energy. In the nonresonant polaron region, a magnetopolaron correction that includes the effects of photon process is observed. In the resonant polaron region, moreover, the resonant magnetopolaron effect accompanied by the emission and absorption of a single photon is distinctly observed. This can be modulated to be far away from the reststrahlen band. The intriguing findings of this paper can be observed experimentally and, in turn, provide a way to measure the strength of the electron-phonon interaction. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
|
|
| |
Language |
|
Wos |
000426041900004 |
Publication Date |
2018-02-26 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.836 |
Times cited |
9 |
Open Access |
|
|
| |
Notes |
; This work was supported by the National Natural Science Foundation of China (Grants No. 11404214 and No. 11455015) and the China Scholarship Council (CSC), Anhui Provincial Natural Science Foundation (Grant No. 1408085QA13), Key Projects of Anhui Provincial Department of Education (Grants No. KJ2017A406 and No. KJ2017A401). B.V.D. was financially supported by the Research Science Foundation-Flanders (FWO-Vl) through a postdoctoral fellowship and M.V.d.D. was financially supported by the Research Science Foundation-Flanders (FWO-Vl) through a doctoral fellowship. ; |
Approved |
Most recent IF: 3.836 |
|
| |
Call Number |
UA @ lucian @ c:irua:149906UA @ admin @ c:irua:149906 |
Serial |
4942 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Hu, S.; Gopinadhan, K.; Rakowski, A.; Neek-Amal, M.; Heine, T.; Grigorieva, I.V.; Haigh, S.J.; Peeters, F.M.; Geim, A.K.; Lozada-Hidalgo, M. |
|
| |
Title |
Transport of hydrogen isotopes through interlayer spacing in van der Waals crystals |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Nature nanotechnology |
Abbreviated Journal |
Nat Nanotechnol |
|
| |
Volume |
13 |
Issue |
6 |
Pages |
468-+ |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Atoms start behaving as waves rather than classical particles if confined in spaces commensurate with their de Broglie wavelength. At room temperature this length is only about one angstrom even for the lightest atom, hydrogen. This restricts quantum-confinement phenomena for atomic species to the realm of very low temperatures(1-5). Here, we show that van der Waals gaps between atomic planes of layered crystals provide angstrom-size channels that make quantum confinement of protons apparent even at room temperature. Our transport measurements show that thermal protons experience a notably higher barrier than deuterons when entering van der Waals gaps in hexagonal boron nitride and molybdenum disulfide. This is attributed to the difference in the de Broglie wavelengths of the isotopes. Once inside the crystals, transport of both isotopes can be described by classical diffusion, albeit with unexpectedly fast rates comparable to that of protons in water. The demonstrated angstrom-size channels can be exploited for further studies of atomistic quantum confinement and, if the technology can be scaled up, for sieving hydrogen isotopes. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000434715700015 |
Publication Date |
2018-04-04 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1748-3387; 1748-3395 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
38.986 |
Times cited |
32 |
Open Access |
|
|
| |
Notes |
; The authors acknowledge support from the Lloyd's Register Foundation, EPSRC – EP/N010345/1, the European Research Council ARTIMATTER project – ERC-2012-ADG and from Graphene Flagship. M.L.-H. acknowledges a Leverhulme Early Career Fellowship. ; |
Approved |
Most recent IF: 38.986 |
|
| |
Call Number |
UA @ lucian @ c:irua:152014UA @ admin @ c:irua:152014 |
Serial |
5046 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Dabral, A.; Pourtois, G.; Sankaran, K.; Magnus, W.; Yu, H.; de de Meux, A.J.; Lu, A.K.A.; Clima, S.; Stokbro, K.; Schaekers, M.; Collaert, N.; Horiguchi, N.; Houssa, M. |
|
| |
Title |
Study of the intrinsic limitations of the contact resistance of metal/semiconductor interfaces through atomistic simulations |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
ECS journal of solid state science and technology |
Abbreviated Journal |
Ecs J Solid State Sc |
|
| |
Volume |
7 |
Issue |
6 |
Pages |
N73-N80 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
|
| |
Abstract |
In this contribution, we report a fundamental study of the factors that set the contact resistivity between metals and highly doped n-type 2D and 3D semiconductors. We investigate the case of n-type doped Si contacted with amorphous TiSi combining first principles calculations with Non-Equilibrium Green functions transport simulations. The evolution of the intrinsic contact resistivity with the doping concentration is found to saturate at similar to 2 x 10(-10) Omega.cm(2) for the case of TiSi and imposes an intrinsic limit to the ultimate contact resistance achievable for n-doped Silamorphous-TiSi (aTiSi). The limit arises from the intrinsic properties of the semiconductors and of the metals such as their electron effective masses and Fermi energies. We illustrate that, in this regime, contacting heavy electron effective mass metals with semiconductor helps reducing the interface intrinsic contact resistivity. This observation seems to hold true regardless of the 3D character of the semiconductor, as illustrated for the case of three 2D semiconducting materials, namely MoS2, ZrS2 and HfS2. (C) The Author(s) 2018. Published by ECS. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Electrochemical society |
Place of Publication |
Pennington (N.J.) |
Editor |
|
|
| |
Language |
|
Wos |
000440836000004 |
Publication Date |
2018-05-25 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2162-8769; 2162-8777 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
1.787 |
Times cited |
2 |
Open Access |
Not_Open_Access |
|
| |
Notes |
; The authors thank the imec core CMOS program members, the European Commission, its TAKEMI5 ECSEL research project and the local authorities for their support. ; |
Approved |
Most recent IF: 1.787 |
|
| |
Call Number |
UA @ lucian @ c:irua:153205UA @ admin @ c:irua:153205 |
Serial |
5130 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Mulkers, J.; Hals, K.M.D.; Leliaert, J.; Milošević, M.V.; Van Waeyenberge, B.; Everschor-Sitte, K. |
|
| |
Title |
Effect of boundary-induced chirality on magnetic textures in thin films |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
| |
Volume |
98 |
Issue |
6 |
Pages |
064429 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
In the quest for miniaturizing magnetic devices, the effects of boundaries and surfaces become increasingly important. Here we show how the recently predicted boundary-induced Dzyaloshinskii-Moriya interaction (DMI) affects the magnetization of ferromagnetic films with a C-infinity v symmetry and a perpendicular magnetic anisotropy. For an otherwise uniformly magnetized film, we find a surface twist when the magnetization in the bulk is canted by an in-plane external field. This twist at the surfaces caused by the boundary-induced DMI differs from the common canting caused by internal DMI observed at the edges of a chiral magnet. Furthermore, we find that the surface twist due to the boundary-induced DMI strongly affects the width of the domain wall at the surfaces. We also find that the skyrmion radius increases in the depth of the film, with the average size of the skyrmion increasing with boundary-induced DMI. This increase suggests that the boundary-induced DMI contributes to the stability of the skyrmion. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
|
|
| |
Language |
|
Wos |
000443394600004 |
Publication Date |
2018-08-31 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.836 |
Times cited |
9 |
Open Access |
|
|
| |
Notes |
; The authors thank Matthias Sitte and Andre Thiaville for fruitful discussions. This work was supported by the Fonds Wetenschappelijk Onderzoek (FWO-Vlaanderen) through Project No. G098917N and the German Research Foundation (DFG) under the Project No. EV 196/2-1. J.L. is supported by the Ghent University Special Research Fund with a BOF postdoctoral fellowship. ; |
Approved |
Most recent IF: 3.836 |
|
| |
Call Number |
UA @ lucian @ c:irua:153706UA @ admin @ c:irua:153706 |
Serial |
5093 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Marikutsa, A.; Rumyantseva, M.; Gaskov, A.; Batuk, M.; Hadermann, J.; Sarmadian, N.; Saniz, R.; Partoens, B.; Lamoen, D. |
|
| |
Title |
Effect of zinc oxide modification by indium oxide on microstructure, adsorbed surface species, and sensitivity to CO |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Frontiers in materials |
Abbreviated Journal |
|
|
| |
Volume |
6 |
Issue |
6 |
Pages |
|
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
|
| |
Abstract |
Additives in semiconductor metal oxides are commonly used to improve sensing behavior of gas sensors. Due to complicated effects of additives on the materials microstructure, adsorption sites and reactivity to target gases the sensing mechanism with modified metal oxides is a matter of thorough research. Herein, we establish the promoting effect of nanocrystalline zinc oxide modification by 1-7 at.% of indium on the sensitivity to CO gas due to improved nanostructure dispersion and concentration of active sites. The sensing materials were synthesized via an aqueous coprecipitation route. Materials composition, particle size and BET area were evaluated using X-ray diffraction, nitrogen adsorption isotherms, high-resolution electron microscopy techniques and EDX-mapping. Surface species of chemisorbed oxygen, OH-groups, and acid sites were characterized by probe molecule techniques and infrared spectroscopy. It was found that particle size of zinc oxide decreased and the BET area increased with the amount of indium oxide. The additive was observed as amorphous indium oxide segregated on agglomerated ZnO nanocrystals. The measured concentration of surface species was higher on In2O3-modified zinc oxide. With the increase of indium oxide content, the sensor response of ZnO/In2O3 to CO was improved. Using in situ infrared spectroscopy, it was shown that oxidation of CO molecules was enhanced on the modified zinc oxide surface. The effect of modifier was attributed to promotion of surface OH-groups and enhancement of CO oxidation on the segregated indium ions, as suggested by DFT in previous work. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000461540600001 |
Publication Date |
2019-03-15 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2296-8016 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
|
Times cited |
11 |
Open Access |
OpenAccess |
|
| |
Notes |
; Research was supported by the grant from Russian Science Foundation (project No. 18-73-00071). ; |
Approved |
Most recent IF: NA |
|
| |
Call Number |
UA @ admin @ c:irua:158540 |
Serial |
5205 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Lozano, D.P.; Couet, S.; Petermann, C.; Hamoir, G.; Jochum, J.K.; Picot, T.; Menendez, E.; Houben, K.; Joly, V.; Antohe, V.A.; Hu, M.Y.; Leu, B.M.; Alatas, A.; Said, A.H.; Roelants, S.; Partoens, B.; Milošević, M.V.; Peeters, F.M.; Piraux, L.; Van de Vondel, J.; Vantomme, A.; Temst, K.; Van Bael, M.J. |
|
| |
Title |
Experimental observation of electron-phonon coupling enhancement in Sn nanowires caused by phonon confinement effects |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
| |
Volume |
99 |
Issue |
6 |
Pages |
064512 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Reducing the size of a superconductor below its characteristic length scales can either enhance or suppress its critical temperature (T-c). Depending on the bulk value of the electron-phonon coupling strength, electronic and phonon confinement effects will play different roles in the modification of T-c. Experimentally disentangling each contribution has remained a challenge. We have measured both the phonon density of states and T-c of Sn nanowires with diameters of 18, 35, and 100 nm in order to quantify the effects of phonon confinement on superconductivity. We observe a shift of the phonon frequency towards the low-energy region and an increase in the electron-phonon coupling constant that can account for the measured increase in T-c. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000459322400005 |
Publication Date |
2019-02-21 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.836 |
Times cited |
8 |
Open Access |
|
|
| |
Notes |
; We would like to thanks Jeroen Scheerder and Wout Keijers for their help and assistance during the low-temperature measurements. This work was supported by the Research Foundation Flanders (FWO), the Concerted Research Action (GOA/14/ 007), the Federation Wallonie-Bruxelles (ARC 13/18-052, Supracryst) and the Fonds de la Recherche Scientifique -FNRS under Grant No. T.0006.16. The authors acknowledge Hercules Stichting (Project Nos. AKUL/13/19 and AKUL/13/25). D.P.L. thanks the FWO for financial support. This research used resources of the Advanced Photon Source, a US Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. ; |
Approved |
Most recent IF: 3.836 |
|
| |
Call Number |
UA @ admin @ c:irua:158621 |
Serial |
5212 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Topalovic, D.B.; Arsoski, V.V.; Tadic, M.Z.; Peeters, F.M. |
|
| |
Title |
Asymmetric versus symmetric HgTe/CdxHg1-x Te double quantum wells: Bandgap tuning without electric field |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Journal Of Applied Physics |
Abbreviated Journal |
J Appl Phys |
|
| |
Volume |
128 |
Issue |
6 |
Pages |
064301-64308 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
We investigate the electron states in double asymmetric HgTe / Cd x Hg 1 – x Te quantum wells grown along the [ 001 ] direction. The subbands are computed by means of the envelope function approximation applied to the eight-band Kane k . mml:mspace width=“.1em”mml:mspace p model. The asymmetry of the confining potential of the double quantum wells results in a gap opening, which is absent in the symmetric system where it can only be induced by an applied electric field. The bandgap and the subbands are affected by spin-orbit coupling, which is a consequence of the asymmetry of the confining potential. The electron-like and hole-like states are mainly confined in different quantum wells, and the enhanced hybridization between them opens a spin-dependent hybridization gap at a finite in-plane wavevector. We show that both the ratio of the widths of the two quantum wells and the mole fraction of the C d x H g 1 – x Te barrier control both the energy gap between the hole-like states and the hybridization gap. The energy subbands are shown to exhibit inverted ordering, and therefore, a nontrivial topological phase could emerge in the system. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000561339300001 |
Publication Date |
2020-08-10 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0021-8979; 1089-7550 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.2 |
Times cited |
3 |
Open Access |
|
|
| |
Notes |
; This research was funded by the Ministry of Education, Science and Technological Development of the Republic of Serbia and the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.2; 2020 IF: 2.068 |
|
| |
Call Number |
UA @ admin @ c:irua:171146 |
Serial |
6453 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Wang, J.; Andelkovic, M.; Wang, G.; Peeters, F.M. |
|
| |
Title |
Molecular collapse in graphene: Sublattice symmetry effect |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
|
| |
Volume |
102 |
Issue |
6 |
Pages |
064108-8 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Atomic collapse can be observed in graphene because of its large “effective” fine structure constant, which enables this phenomenon to occur for an impurity charge as low as Z(c) similar to 1-2. Here we investigate the effect of the sublattice symmetry on molecular collapse in two spatially separated charge tunable vacancies, which are located on the same (A-A type) or different (A-B type) sublattices. We find that the broken sublattice symmetry: (1) does not affect the location of the main bonding and antibonding molecular collapse peaks, (2) but shifts the position of the satellite peaks, because they are a consequence of the breaking of the local sublattice symmetry, and (3) there are vacancy characteristic collapse peaks that only occur for A-B type vacancies, which can be employed to distinguish them experimentally from the A-A type. As the charge, energy, and separation distance increase, the additional collapse features merge with the main molecular collapse peaks. We show that the spatial distribution around the vacancy site of the collapse states allows us to differentiate the molecular from the frustrated collapse. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000562320700002 |
Publication Date |
2020-08-25 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.7 |
Times cited |
1 |
Open Access |
|
|
| |
Notes |
; This work was supported by the National Natural Science Foundation of China (Grants No. 61874038 and No. 61704040), National Key R&D Program Grant 2018YFE0120000, the scholarship from China Scholarship Council (CSC: 201908330548), and TRANS2DTMD FlagEra project. ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
|
| |
Call Number |
UA @ admin @ c:irua:172065 |
Serial |
6562 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Griffin, E.; Mogg, L.; Hao, G.-P.; Kalon, G.; Bacaksiz, C.; Lopez-Polin, G.; Zhou, T.Y.; Guarochico, V.; Cai, J.; Neumann, C.; Winter, A.; Mohn, M.; Lee, J.H.; Lin, J.; Kaiser, U.; Grigorieva, I., V; Suenaga, K.; Ozyilmaz, B.; Cheng, H.-M.; Ren, W.; Turchanin, A.; Peeters, F.M.; Geim, A.K.; Lozada-Hidalgo, M. |
|
| |
Title |
Proton and Li-Ion permeation through graphene with eight-atom-ring defects |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Acs Nano |
Abbreviated Journal |
Acs Nano |
|
| |
Volume |
14 |
Issue |
6 |
Pages |
7280-7286 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Defect-free graphene is impermeable to gases and liquids but highly permeable to thermal protons. Atomic-scale defects such as vacancies, grain boundaries, and Stone-Wales defects are predicted to enhance graphene's proton permeability and may even allow small ions through, whereas larger species such as gas molecules should remain blocked. These expectations have so far remained untested in experiment. Here, we show that atomically thin carbon films with a high density of atomic-scale defects continue blocking all molecular transport, but their proton permeability becomes similar to 1000 times higher than that of defect-free graphene. Lithium ions can also permeate through such disordered graphene. The enhanced proton and ion permeability is attributed to a high density of eight-carbon-atom rings. The latter pose approximately twice lower energy barriers for incoming protons compared to that of the six-atom rings of graphene and a relatively low barrier of similar to 0.6 eV for Li ions. Our findings suggest that disordered graphene could be of interest as membranes and protective barriers in various Li-ion and hydrogen technologies. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000543744100086 |
Publication Date |
2020-05-19 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1936-0851 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
17.1 |
Times cited |
34 |
Open Access |
|
|
| |
Notes |
; The work was supported by the Lloyd's Register Foundation, EPSRC-EP/N010345/1, the European Research Council, the Graphene Flagship, the Deutsche Forschungsgemeinschaft project TRR 234 “CataLight” (Project B7, Grant No. 364549901), and the research infrastructure Grant No. INST 275/25 7-1 FUGG. E.G. and L.M. acknowledge the EPSRC NowNANO programme for funding. ; |
Approved |
Most recent IF: 17.1; 2020 IF: 13.942 |
|
| |
Call Number |
UA @ admin @ c:irua:170708 |
Serial |
6586 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Zhang, L.; Zhang, Y.-Y.; Zha, G.-Q.; Milošević, M.V.; Zhou, S.-P. |
|
| |
Title |
Skyrmionic chains and lattices in s plus id superconductors |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
|
| |
Volume |
101 |
Issue |
6 |
Pages |
064501 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
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. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000510745600005 |
Publication Date |
2020-02-03 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.7 |
Times cited |
7 |
Open Access |
|
|
| |
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 |
|
| |
Call Number |
UA @ admin @ c:irua:166507 |
Serial |
6605 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Van der Donck, M.; Conti, S.; Perali, A.; Hamilton, A.R.; Partoens, B.; Peeters, F.M.; Neilson, D. |
|
| |
Title |
Three-dimensional electron-hole superfluidity in a superlattice close to room temperature |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
|
| |
Volume |
102 |
Issue |
6 |
Pages |
060503 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Although there is strong theoretical and experimental evidence for electron-hole superfluidity in separated sheets of electrons and holes at low T, extending superfluidity to high T is limited by strong two-dimensional fluctuations and Kosterlitz-Thouless effects. We show this limitation can be overcome using a superlattice of alternating electron- and hole-doped semiconductor monolayers. The superfluid transition in a three-dimensional superlattice is not topological, and for strong electron-hole pair coupling, the transition temperature T-c can be at room temperature. As a quantitative illustration, we show T-c can reach 270 K for a superfluid in a realistic superlattice of transition metal dichalcogenide monolayers. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000562320700001 |
Publication Date |
2020-08-25 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.7 |
Times cited |
5 |
Open Access |
|
|
| |
Notes |
; This work was supported by the Research Foundation of Flanders (FWO-Vl) through an aspirant research grant for M.V.d.D., by the FLAG-ERA project TRANS-2D-TMD, and by the Australian Government through the Australian Research Council Centre of Excellence in Future Low-Energy Electronics (Project No. CE170100039). We thank Milorad V. Milossevi ' c, Pierbiagio Pieri, and Jacques Tempere for helpful discussions. ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
|
| |
Call Number |
UA @ admin @ c:irua:172064 |
Serial |
6628 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Torsello, D.; Ummarino, G.A.; Bekaert, J.; Gozzelino, L.; Gerbaldo, R.; Tanatar, M.A.; Canfield, P.C.; Prozorov, R.; Ghigo, G. |
|
| |
Title |
Tuning the intrinsic anisotropy with disorder in the CaKFE₄As₄ superconductor |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Physical Review Applied |
Abbreviated Journal |
Phys Rev Appl |
|
| |
Volume |
13 |
Issue |
6 |
Pages |
064046-64049 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
We report on the anisotropy of the London penetration depth of CaKFe4As4, discussing how it relates to its electronic structure and how it modifies under introduction of disorder, both chemically induced (by Ni substitution) and irradiation induced (by 3.5-MeV protons). Indeed, CaKFe4As4 is particularly suitable for the study of fundamental superconducting properties due to its stoichiometric composition, exhibiting clean-limit behavior in the pristine samples and having a fairly high critical temperature, T-c approximate to 35 K. The London penetration depth lambda(L) is measured with a microwave-coplanar-resonator technique that allows us to deconvolve the anisotropic contributions lambda(L,ab) and lambda(L,c) and obtain the anisotropy parameter gamma(lambda) = lambda(L,c)/lambda(L,ab). The gamma(lambda) (T) found for the undoped pristine sample is in good agreement with previous literature and is here compared to ab initio density-functional-theory and Eliashberg calculations. The dependence of gamma(lambda) (T) on both chemical and irradiation-induced disorder is discussed to highlight which method is more suitable to decrease the direction dependence of the electromagnetic properties while maintaining a high critical temperature. Lastly, the relevance of an intrinsic anisotropy such as gamma(lambda) on application-related anisotropic parameters (critical current, pinning) is discussed in light of the recent employment of CaKFe4As4 in the production of wires. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000540915800003 |
Publication Date |
2020-06-19 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.6 |
Times cited |
4 |
Open Access |
|
|
| |
Notes |
; This work was partially supported by the Italian Ministry of Education, University and Research (Project PRIN “HIBiSCUS,” Grant No. 201785KWLE). J.B. acknowledges the support of a postdoctoral fellowship of the Research Foundation-Flanders (FWO). The computational resources and services used for the first-principles calculations in this work were provided by the VSC (Flemish Supercomputer Center), funded by the FWO and the Flemish Government-department EWI. Work done at Ames Laboratory was supported by the U.S. Department of Energy, Office of Basic Energy Science, Division of Materials Sciences and Engineering. Ames Laboratory is operated for the U.S. Department of Energy by Iowa State University under Contract No. DE-AC02-07CH11358. G.A.U. acknowledges support from the MEPhI Academic Excellence Project (Contract No. 702.a03.21.0005). ; |
Approved |
Most recent IF: 4.6; 2020 IF: 4.808 |
|
| |
Call Number |
UA @ admin @ c:irua:170178 |
Serial |
6641 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Raymenants, E.; Bultynck, O.; Wan, D.; Devolder, T.; Garello, K.; Souriau, L.; Thiam, A.; Tsvetanova, D.; Canvel, Y.; Nikonov, D.E.; Young, I.A.; Heyns, M.; Sorée, B.; Asselberghs, I.; Radu, I.; Couet, S.; Nguyen, V.D. |
|
| |
Title |
Nanoscale domain wall devices with magnetic tunnel junction read and write |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Nature Electronics |
Abbreviated Journal |
|
|
| |
Volume |
4 |
Issue |
6 |
Pages |
392-398 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
|
| |
Abstract |
The manipulation of fast domain wall motion in magnetic nanostructures could form the basis of novel magnetic memory and logic devices. However, current approaches for reading and writing domain walls require external magnetic fields, or are based on conventional magnetic tunnel junctions (MTJs) that are not compatible with high-speed domain wall motion. Here we report domain wall devices based on perpendicular MTJs that offer electrical read and write, and fast domain wall motion via spin-orbit torque. The devices have a hybrid free layer design that consists of platinum/cobalt (Pt/Co) or a synthetic antiferromagnet (Pt/Co/Ru/Co) into the free layer of conventional MTJs. We show that our devices can achieve good tunnelling magnetoresistance readout and efficient spin-transfer torque writing that is comparable to current magnetic random-access memory technology, as well as domain wall depinning efficiency that is similar to stand-alone materials. We also show that a domain wall conduit based on a synthetic antiferromagnet offers the potential for reliable domain wall motion and faster write speed compared with a device based on Pt/Co. Domain wall devices based on perpendicular magnetic tunnel junctions with a hybrid free layer design can offer electrical read and write, and fast domain wall motion driven via spin-orbit torque. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000665011500005 |
Publication Date |
2021-06-23 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2520-1131 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
|
Times cited |
|
Open Access |
OpenAccess |
|
| |
Notes |
|
Approved |
Most recent IF: NA |
|
| |
Call Number |
UA @ admin @ c:irua:179673 |
Serial |
7003 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Sethu, K.K.V.; Ghosh, S.; Couet, S.; Swerts, J.; Sorée, B.; De Boeck, J.; Kar, G.S.; Garello, K. |
|
| |
Title |
Optimization of tungsten beta-phase window for spin-orbit-torque magnetic random-access memory |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Physical Review Applied |
Abbreviated Journal |
Phys Rev Appl |
|
| |
Volume |
16 |
Issue |
6 |
Pages |
064009 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Switching induced by spin-orbit torque (SOT) is being vigorously explored, as it allows the control of magnetization using an in-plane current, which enables a three-terminal magnetic-tunnel-junction geometry with isolated read and write paths. This significantly improves the device endurance and the read stability, and allows reliable subnanosecond switching. Tungsten in the beta phase, beta-W, has the largest reported antidamping SOT charge-to-spin conversion ratio (theta(AD) approximate to -60%) for heavy metals. However, beta-W has a limitation when one is aiming for reliable technology integration: the beta phase is limited to a thickness of a few nanometers and enters the alpha phase above 4 nm in our samples when industry-relevant deposition tools are used. Here, we report our approach to extending the range of beta-W, while simultaneously improving the SOT efficiency by introducing N and O doping of W. Resistivity and XRD measurements confirm the extension of the beta phase from 4 nm to more than 10 nm, and transport characterization shows an effective SOT efficiency larger than -44.4% (reaching approximately -60% for the bulk contribution). In addition, we demonstrate the possibility of controlling and enhancing the perpendicular magnetic anisotropy of a storage layer (Co-Fe-B). Further, we integrate the optimized W(O, N) into SOT magnetic random-access memory (SOT-MRAM) devices and project that, for the same thickness of SOT material, the switching current decreases by 25% in optimized W(O, N) compared with our standard W. Our results open the path to using and further optimizing W for integration of SOT-MRAM technology. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000729005800002 |
Publication Date |
2021-12-03 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.808 |
Times cited |
|
Open Access |
Not_Open_Access |
|
| |
Notes |
|
Approved |
Most recent IF: 4.808 |
|
| |
Call Number |
UA @ admin @ c:irua:184832 |
Serial |
7007 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Zhang, G.; Huang, S.; Chaves, A.; Yan, H. |
|
| |
Title |
Black phosphorus as tunable Van der Waals quantum wells with high optical quality |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
ACS nano |
Abbreviated Journal |
|
|
| |
Volume |
17 |
Issue |
6 |
Pages |
6073-6080 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Van der Waals quantum wells, naturally formed in two-dimensional layered materials with nanoscale thickness, possess many inherent advantages over conventional molecular beam epitaxy grown counterparts, and could bring up intriguing physics and applications. However, optical transitions originated from the series of quantized states in these emerging quantum wells are still elusive. Here, we show that multilayer black phosphorus appears to be an excellent candidate for van der Waals quantum wells with well-defined subbands and high optical quality. Using infrared absorption spectroscopy, we probe subband structures of multilayer black phosphorus with tens of atomic layers, revealing clear signatures for optical transitions with subband index as high as 10, far from what was attainable previously. Surprisingly, in addition to allowed transitions, an unexpected series of “forbidden” transitions is also evidently observed, which enables us to determine energy spacings separately for conduction and valence subbands. Furthermore, the linear tunability of subband spacings by temperature and strain is demonstrated. Our results are expected to facilitate potential applications for infrared optoelectronics based on tunable van der Waals quantum wells. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000953463300001 |
Publication Date |
2023-03-13 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1936-0851 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
17.1 |
Times cited |
|
Open Access |
Not_Open_Access |
|
| |
Notes |
|
Approved |
Most recent IF: 17.1; 2023 IF: 13.942 |
|
| |
Call Number |
UA @ admin @ c:irua:196100 |
Serial |
7565 |
|
| Permanent link to this record |
