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Author |
Callewaert, V.; Saniz, R.; Barbiellini, B.; Partoens, B. |
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Title |
Surface states and positron annihilation spectroscopy: results and prospects from a first-principles approach |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Journal of physics : conference series |
Abbreviated Journal  |
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| |
Volume |
791 |
Issue |
791 |
Pages |
012036 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The trapping of positrons at the surface of a material can be exploited to study quite selectively the surface properties of the latter by means of positron annihilation spectroscopy techniques. To support these, it is desirable to be able to theoretically predict the existence of such positronic surface states and to describe their annihilation characteristics with core or valence surface electrons in a reliable way. Here, we build on the well-developed first-principles techniques for the study of positrons in bulk solids as well as on previous models for surfaces, and investigate two schemes that can improve the theoretical description of the interaction of positrons with surfaces. One is based on supplementing the local-density correlation potential with the corrugated image potential at the surface, and the other is based on the weighted-density approximation to correlation. We discuss our results for topological insulators, graphene layers, and quantum dots, with emphasis on the information that can be directly related to experiment. We also discuss some open theoretical problems that should be addressed by future research. |
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Wos |
000400610500036 |
Publication Date |
2017-02-22 |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1742-6588 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
1 |
Open Access |
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Notes |
We acknowledge financial support from FWO-Vlaanderen (projects G.0150.13 and G.0224.14N). This work was carried out using the HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center (VSC), funded by the Hercules foundation and the Flemish Government (EWI Department). The work at Northeastern University was supported by the US Department of Energy (DOE), Office of Science, Basic Energy Sciences grant number DE-FG02-07ER46352 (core research), and benefited from Northeastern University’s Advanced Scientific Computation Center (ASCC), the NERSC supercomputing center through DOE grant number DE-AC02- 05CH11231, and support (applications to layered materials) from the DOE EFRC: Center for the Computational Design of Functional Layered Materials (CCDM) under DE-SC0012575. |
Approved |
Most recent IF: NA |
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Call Number |
CMT @ cmt @ c:irua:140847 |
Serial |
4425 |
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| Permanent link to this record |
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Author |
Moldovan, D.; Peeters, F.M. |
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Title |
Atomic Collapse in Graphene |
Type |
P1 Proceeding |
| |
Year |
2016 |
Publication |
Nanomaterials For Security |
Abbreviated Journal |
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Volume |
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Issue |
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Pages |
3-17 |
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Keywords |
P1 Proceeding; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
When the charge Z of an atom exceeds the critical value of 170, it will undergo a process called atomic collapse which triggers the spontaneous creation of electron-positron pairs. The high charge requirements have prevented the observation of this phenomenon with real atomic nuclei. However, thanks to the relativistic nature of the carriers in graphene, the same physics is accessible at a much lower scale. The atomic collapse analogue in graphene is realized using artificial nuclei which can be created via the deposition of impurities on the surface of graphene or using charged vacancies. These supercritically charged artificial nuclei trap electrons in a sequence of quasi-bound states which can be observed experimentally as resonances in the local density of states. |
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Publisher |
Springer |
Place of Publication |
Dordrecht |
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Wos |
000386506200001 |
Publication Date |
2016-07-20 |
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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 |
978-94-017-7593-9; 978-94-017-7591-5 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
3 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:138237 |
Serial |
4348 |
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Author |
Sobrino Fernández, M. |
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Title |
Confinement induced assembly of anisotropic particles : patchy colloids and water molecules |
Type |
Doctoral thesis |
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Year |
2016 |
Publication |
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Abbreviated Journal |
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Pages |
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Keywords |
Doctoral thesis; Condensed Matter Theory (CMT) |
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Antwerpen |
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Additional Links |
UA library record |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:135841 |
Serial |
4349 |
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Author |
Moldovan, D. |
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Title |
Electronic properties of strained graphene and supercritical charge centers |
Type |
Doctoral thesis |
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Year |
2016 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
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Keywords |
Doctoral thesis; Condensed Matter Theory (CMT) |
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Antwerpen |
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UA library record |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:135792 |
Serial |
4352 |
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Author |
Van de Put, M.L. |
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Title |
Modeling of quantum electron transport with applications in energy filtering nanostructures |
Type |
Doctoral thesis |
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Year |
2016 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
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Keywords |
Doctoral thesis; Condensed Matter Theory (CMT) |
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Antwerpen |
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Additional Links |
UA library record |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:138752 |
Serial |
4357 |
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Author |
Verreck, D.; Verhulst, A.S.; Sorée, B.; Collaert, N.; Mocuta, A.; Thean, A.; Groeseneken, G. |
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Title |
Non-uniform strain in lattice-mismatched heterostructure tunnel field-effect transistors |
Type |
P1 Proceeding |
| |
Year |
2016 |
Publication |
Solid-State Device Research (ESSDERC), European Conference
T2 – 46th European Solid-State Device Research Conference (ESSDERC) / 42nd, European Solid-State Circuits Conference (ESSCIRC), SEP 12-15, 2016, Lausanne, SWITZERLAND |
Abbreviated Journal |
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Volume |
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Issue |
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Pages |
412-415 |
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Keywords |
P1 Proceeding; Condensed Matter Theory (CMT) |
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Abstract |
Because of its localized impact on the band structure, non-uniform strain at the heterojunction between lattice-mismatched materials has the potential to significantly enlarge the design space for tunnel-field effect transistors (TFET). However, the impact of a complex strain profile on TFET performance is difficult to predict. We have therefore developed a 2D quantum mechanical transport formalism capable of simulating the effects of a general non-uniform strain. We demonstrate the formalism for the GaAsxSb(1-x)/InyGa(1-y) As system and show that a performance improvement over a lattice-matched reference is indeed possible, allowing for relaxed requirements on the source doping. We also point out that the added design parameter of mismatch is not free, but limited by the desired effective bandgap at the tunnel junction. |
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Ieee |
Place of Publication |
New york |
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Series Editor |
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Abbreviated Series Title |
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Edition |
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ISSN |
978-1-5090-2969-3 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:138233 |
Serial |
4358 |
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Author |
Eijt, S.W.H.; Shi, W.; Mannheim, A.; Butterling, M.; Schut, H.; Egger, W.; Dickmann, M.; Hugenschmidt, C.; Shakeri, B.; Meulenberg, R.W.; Callewaert, V.; Saniz, R.; Partoens, B.; Barbiellini, B.; Bansil, A.; Melskens, J.; Zeman, M.; Smets, A.H.M.; Kulbak, M.; Hodes, G.; Cahen, D.; Brück, E. |
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Title |
New insights into the nanostructure of innovative thin film solar cells gained by positron annihilation spectroscopy |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
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Volume |
791 |
Issue |
791 |
Pages |
012021 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Recent studies showed that positron annihilation methods can provide key insights into the nanostructure and electronic structure of thin film solar cells. In this study, positron annihilation lifetime spectroscopy (PALS) is applied to investigate CdSe quantum dot (QD) light absorbing layers, providing evidence of positron trapping at the surfaces of the QDs. This enables one to monitor their surface composition and electronic structure. Further, 2D-Angular Correlation of Annihilation Radiation (2D-ACAR) is used to investigate the nanostructure of divacancies in photovoltaic-high-quality a-Si:H films. The collected momentum distributions were converted by Fourier transformation to the direct space representation of the electron-positron autocorrelation function. The evolution of the size of the divacancies as a function of hydrogen dilution during deposition of a-Si:H thin films was examined. Finally, we present a first positron Doppler Broadening of Annihilation Radiation (DBAR) study of the emerging class of highly efficient thin film solar cells based on perovskites. |
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Corporate Author |
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Place of Publication |
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Language |
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Wos |
000400610500021 |
Publication Date |
2017-02-22 |
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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 |
1742-6588 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
1 |
Open Access |
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Notes |
The work at Delft University of Technology was supported by the China Scholarship Council (CSC) grant of W.S., by ADEM, A green Deal in Energy Materials of the Ministry of Economic Affairs of The Netherlands (www.adem- innovationlab.nl), and the STW Vidi grant of A.S., Grant No. 10782. The PALS study is based upon experiments performed at the PLEPS instrument of the NEPOMUC facility at the Heinz Maier-Leibnitz Zentrum (MLZ), Garching, Germany, and was supported by the European Commission under the 7 th Framework Programme, Key Action: Strengthening the European Research Area, Research Infrastructures, Contract No. 226507, NMI3. The work at University of Maine was supported by the National Science Foundation under Grant No. DMR-1206940. Research at the University of Antwerp was supported by FWO grants G022414N and G015013. The work at Northeastern University was supported by the US Department of Energy (DOE), Office of Science, Basic Energy Sciences grant number DE-FG02-07ER46352 (core research), and benefited from Northeastern University's Advanced Scientific Computation Center (ASCC), the NERSC supercomputing center through DOE grant number DE-AC02-05CH11231, and support (applications to layered materials) from the DOE EFRC: Center for the Computational Design of Functional Layered Materials (CCDM) under DE-SC0012575. The work at the Weizmann Institute was supported by the Sidney E. Frank Foundation through the Israel Science Foundation, by the Israel Ministry of Science, and the Israel National Nano-Initiative. D.C. holds the Sylvia and Rowland Schaefer Chair in Energy Research. |
Approved |
Most recent IF: NA |
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Call Number |
CMT @ cmt @ c:irua:140850 |
Serial |
4426 |
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Author |
Neilson, D.; Perali, A.; Zarenia, M. |
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Title |
Many-body electron correlations in graphene |
Type |
P1 Proceeding |
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Year |
2016 |
Publication |
(mbt18) |
Abbreviated Journal |
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Volume |
702 |
Issue |
702 |
Pages |
012008 |
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Keywords |
P1 Proceeding; Condensed Matter Theory (CMT) |
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Abstract |
The conduction electrons in graphene promise new opportunities to access the region of strong many-body electron-electron correlations. Extremely high quality, atomically flat two-dimensional electron sheets and quasi-one-dimensional electron nanoribbons with tuneable band gaps that can be switched on by gates, should exhibit new many-body phenomena that have long been predicted for the regions of phase space where the average Coulomb repulsions between electrons dominate over their Fermi energies. In electron nanoribbons a few nanometres wide etched in monolayers of graphene, the quantum size effects and the van Hove singularities in their density of states further act to enhance electron correlations. For graphene multilayers or nanoribbons in a double unit electron-hole geometry, it is possible for the many-body electron-hole correlations to be made strong enough to stabilise high-temperature electron- hole superfluidity. |
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Corporate Author |
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Publisher |
Iop publishing ltd |
Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000389756000008 |
Publication Date |
2016-04-29 |
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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 |
702 |
Series Issue |
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Edition |
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ISSN |
1742-6588; 1742-6596 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
3 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:140268 |
Serial |
4455 |
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Author |
Tiwari, S.; Van de Put, M.L.; Temst, K.; Vandenberghe, W.G.; Sorée, B. |
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Title |
Atomistic modeling of spin and electron dynamics in two-dimensional magnets switched by two-dimensional topological insulators |
Type |
A1 Journal article |
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Year |
2023 |
Publication |
Physical review applied |
Abbreviated Journal |
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Volume |
19 |
Issue |
1 |
Pages |
014040-14049 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
To design fast memory devices, we need material combinations that can facilitate fast read and write operations. We present a heterostructure comprising a two-dimensional (2D) magnet and a 2D topological insulator (TI) as a viable option for designing fast memory devices. We theoretically model the spin-charge dynamics between 2D magnets and 2D TIs. Using the adiabatic approximation, we combine the nonequi-librium Green's function method for spin-dependent electron transport and a time-quantified Monte Carlo method for simulating magnetization dynamics. We show that it is possible to switch a magnetic domain of a ferromagnet using the spin torque from spin-polarized edge states of a 2D TI. We show further that the switching of 2D magnets by TIs is strongly dependent on the interface exchange (Jint), and an opti-mal interface exchange, is required for efficient switching. Finally, we compare experimentally grown Cr compounds and show that Cr compounds with higher anisotropy (such as CrI3) result in a lower switching speed but a more stable magnetic order. |
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Place of Publication |
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Wos |
000920227500002 |
Publication Date |
2023-01-12 |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2331-7019 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.6 |
Times cited |
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Open Access |
Not_Open_Access |
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Notes |
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Approved |
Most recent IF: 4.6; 2023 IF: 4.808 |
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Call Number |
UA @ admin @ c:irua:194312 |
Serial |
7283 |
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Author |
Harrabi, K.; Gasmi, K.; Mekki, A.; Bahlouli, H.; Kunwar, S.; Milošević, M.V. |
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Title |
Detection and measurement of picoseconds-pulsed laser energy using a NbTiN superconducting filament |
Type |
A1 Journal article |
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Year |
2023 |
Publication |
IEEE transactions on applied superconductivity |
Abbreviated Journal |
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Volume |
33 |
Issue |
5 |
Pages |
2400205-5 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
investigate non-equilibrium states created by a laser beam incident on a superconducting NbTiN filament subject to an electrical pulse at 4 K. In absence of the laser excitation, when the amplitude of the current pulse applied to the filament exceeds the critical current value, we monitored the delay time td that marks the collapse of the superconducting phase which is then followed by a voltage rise. We linked the delay time to the applied current using the time-dependent Ginzburg-Landau (TDGL) theory, which enabled us to deduce the cooling (or heat-removal) time from the fit to the experimental data. Subsequently, we exposed the filament biased with a current pulse close to its critical value to a focused laser beam, inducing a normal state in the impact region of the laser beam. We showed that the energy of the incident beam and the incurred delay time are related to each other by a simple expression, that enables direct measurement of incident beam energy by temporal monitoring of the transport response. This method can be extended for usage in single-photon detection regime, and be used for accurate calibration of an arbitrary light source. |
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Corporate Author |
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Place of Publication |
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Language |
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Wos |
000946265900016 |
Publication Date |
2023-02-14 |
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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 |
1051-8223 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.8 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 1.8; 2023 IF: NA |
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Call Number |
UA @ admin @ c:irua:195110 |
Serial |
7295 |
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Author |
Yedukondalu, N.; Pandey, T.; Roshan, S.C.R. |
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Title |
Effect of hydrostatic pressure on lone pair activity and phonon transport in Bi₂O₂S |
Type |
A1 Journal article |
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Year |
2023 |
Publication |
ACS applied energy materials |
Abbreviated Journal |
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Volume |
6 |
Issue |
4 |
Pages |
2401-2411 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Dibismuth dioxychalcogenides, Bi2O2Ch (Ch = S, Se, Te), are a promising class of materials for next-generation electronics and thermoelectrics due to their ultrahigh carrier mobility and excellent air stability. An interesting member of this family is Bi2O2S, which has a stereochemically active 6s2 lone pair of Bi3+ cations, heterogeneous bonding, and a high mass contrast between its constituent elements. In the present study, we have used first-principles calculations in combination with Boltzmann transport theory to systematically investigate the effect of hydrostatic pressure on lattice dynamics and phonon transport properties of Bi2O2S. We found that the ambient Pnmn phase has a low average lattice thermal conductivity (kappa l) of 1.71 W/(m K) at 300 K. We also predicted that Bi2O2S undergoes a structural phase transition from a low-symmetry (Pnmn) to a high-symmetry (I4/mmm) structure at around 4 GPa due to centering of Bi3+ cations with pressure. Upon compression, the lone pair activity of Bi3+ cations is suppressed, which increases kappa l by almost 3 times to 4.92 W/ (m K) at 5 GPa for the I4/mmm phase. The computed phonon lifetimes and Gru''neisen parameters show that anharmonicity decreases with increasing pressure due to further suppression of the lone pair activity and strengthening of intra-and intermolecular interactions, leading to an average room-temperature kappa l of 12.82 W/(m K) at 20 GPa. Overall, this study provides a comprehensive understanding of the effect of hydrostatic pressure on the stereochemical activity of the lone pair of Bi3+ cations and its implications on the phonon transport properties of Bi2O2S. |
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Corporate Author |
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Publisher |
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Place of Publication |
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Language |
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Wos |
000929103700001 |
Publication Date |
2023-02-08 |
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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 |
2574-0962 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.4 |
Times cited |
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Open Access |
Not_Open_Access |
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| |
Notes |
|
Approved |
Most recent IF: 6.4; 2023 IF: NA |
|
| |
Call Number |
UA @ admin @ c:irua:195245 |
Serial |
7300 |
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| Permanent link to this record |
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| |
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Author |
Mirzakhani, M.; Myoung, N.; Peeters, F.M.; Park, H.C. |
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| |
Title |
Electronic Mach-Zehnder interference in a bipolar hybrid monolayer-bilayer graphene junction |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Carbon |
Abbreviated Journal |
|
|
| |
Volume |
201 |
Issue |
|
Pages |
734-744 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Graphene matter in a strong magnetic field, realizing one-dimensional quantum Hall channels, provides a unique platform for studying electron interference. Here, using the Landauer-Buttiker formalism along with the tightbinding model, we investigate the quantum Hall (QH) effects in unipolar and bipolar monolayer-bilayer graphene (MLG-BLG) junctions. We find that a Hall bar made of an armchair MLG-BLG junction in the bipolar regime results in valley-polarized edgechannel interferences and can operate a fully tunable Mach-Zehnder (MZ) interferometer device. Investigation of the bar-width and magnetic-field dependence of the conductance oscillations shows that the MZ interference in such structures can be drastically affected by the type of (zigzag) edge termination of the second layer in the BLG region [composed of vertical dimer or non-dimer atoms]. Our findings reveal that both interfaces exhibit a double set of Aharonov-Bohm interferences, with the one between two oppositely valley-polarized edge channels dominating and causing a large amplitude conductance oscillation ranging from 0 to 2e2/h. We explain and analyze our findings by analytically solving the Dirac-Weyl equation for a gated semi-infinite MLG-BLG junction. |
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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 |
|
Wos |
000868911500004 |
Publication Date |
2022-09-28 |
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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 |
0008-6223 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
10.9 |
Times cited |
|
Open Access |
Not_Open_Access |
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| |
Notes |
|
Approved |
Most recent IF: 10.9; 2023 IF: 6.337 |
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| |
Call Number |
UA @ admin @ c:irua:191516 |
Serial |
7302 |
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| Permanent link to this record |
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|
Author |
Duden, E.I.; Savaci, U.; Turan, S.; Sevik, C.; Demiroglu, I. |
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| |
Title |
Intercalation of argon in honeycomb structures towards promising strategy for rechargeable Li-ion batteries |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
|
|
| |
Volume |
35 |
Issue |
8 |
Pages |
085301-85311 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
High-performance rechargeable batteries are becoming very important for high-end technologies with their ever increasing application areas. Hence, improving the performance of such batteries has become the main bottleneck to transferring high-end technologies to end users. In this study, we propose an argon intercalation strategy to enhance battery performance via engineering the interlayer spacing of honeycomb structures such as graphite, a common electrode material in lithium-ion batteries (LIBs). Herein, we systematically investigated the LIB performance of graphite and hexagonal boron nitride (h-BN) when argon atoms were sent into between their layers by using first-principles density-functional-theory calculations. Our results showed enhanced lithium binding for graphite and h-BN structures when argon atoms were intercalated. The increased interlayer space doubles the gravimetric lithium capacity for graphite, while the volumetric capacity also increased by around 20% even though the volume was also increased. The ab initio molecular dynamics simulations indicate the thermal stability of such graphite structures against any structural transformation and Li release. The nudged-elastic-band calculations showed that the migration energy barriers were drastically lowered, which promises fast charging capability for batteries containing graphite electrodes. Although a similar level of battery promise was not achieved for h-BN material, its enhanced battery capabilities by argon intercalation also support that the argon intercalation strategy can be a viable route to enhance such honeycomb battery electrodes. |
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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 |
000899825400001 |
Publication Date |
2022-12-05 |
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| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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| |
Impact Factor |
2.7 |
Times cited |
|
Open Access |
OpenAccess |
|
| |
Notes |
|
Approved |
Most recent IF: 2.7; 2023 IF: 2.649 |
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| |
Call Number |
UA @ admin @ c:irua:193399 |
Serial |
7313 |
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| Permanent link to this record |
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| |
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Author |
Kourmoulakis, G.; Michail, A.; Paradisanos, I.; Marie, X.; Glazov, M.M.; Jorissen, B.; Covaci, L.; Stratakis, E.; Papagelis, K.; Parthenios, J.; Kioseoglou, G. |
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| |
Title |
Biaxial strain tuning of exciton energy and polarization in monolayer WS2 |
Type |
A1 Journal Article |
| |
Year |
2023 |
Publication |
Applied Physics Letters |
Abbreviated Journal |
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|
| |
Volume |
123 |
Issue |
22 |
Pages |
|
|
| |
Keywords |
A1 Journal Article; Condensed Matter Theory (CMT) ; |
|
| |
Abstract |
We perform micro-photoluminescence and Raman experiments to examine the impact of biaxial tensile strain on the optical properties of WS2 monolayers. A strong shift on the order of −130 meV per % of strain is observed in the neutral exciton emission at room temperature. Under near-resonant excitation, we measure a monotonic decrease in the circular polarization degree under the applied strain. We experimentally separate the effect of the strain-induced energy detuning and evaluate the pure effect coming from the biaxial strain. The analysis shows that the suppression of the circular polarization degree under the biaxial strain is related to an interplay of energy and polarization relaxation channels as well as to variations in the exciton oscillator strength affecting the long-range exchange interaction. |
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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 |
|
Wos |
001124156400003 |
Publication Date |
2023-11-27 |
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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 |
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| |
Impact Factor |
4 |
Times cited |
|
Open Access |
|
|
| |
Notes |
Hellenic Foundation for Research and Innovation, HFRI-FM17-3034 ; |
Approved |
Most recent IF: 4; 2023 IF: 3.411 |
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| |
Call Number |
CMT @ cmt @c:irua:202178 |
Serial |
8991 |
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| Permanent link to this record |
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Author |
Souza, J.C.B.; Vizarim, N.P.; Reichhardt, C.J.O.; Reichhardt, C.; Venegas, P.A. |
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| |
Title |
Magnus induced diode effect for skyrmions in channels with periodic potentials |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
|
|
| |
Volume |
35 |
Issue |
1 |
Pages |
015804-15810 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
Using a particle based model, we investigate the skyrmion dynamical behavior in a channel where the upper wall contains divots of one depth and the lower wall contains divots of a different depth. Under an applied driving force, skyrmions in the channels move with a finite skyrmion Hall angle that deflects them toward the upper wall for -x direction driving and the lower wall for +x direction driving. When the upper divots have zero height, the skyrmions are deflected against the flat upper wall for -x direction driving and the skyrmion velocity depends linearly on the drive. For +x direction driving, the skyrmions are pushed against the lower divots and become trapped, giving reduced velocities and a nonlinear velocity-force response. When there are shallow divots on the upper wall and deep divots on the lower wall, skyrmions get trapped for both driving directions; however, due to the divot depth difference, skyrmions move more easily under -x direction driving, and become strongly trapped for +x direction driving. The preferred -x direction motion produces what we call a Magnus diode effect since it vanishes in the limit of zero Magnus force, unlike the diode effects observed for asymmetric sawtooth potentials. We show that the transport curves can exhibit a series of jumps or dips, negative differential conductivity, and reentrant pinning due to collective trapping events. We also discuss how our results relate to recent continuum modeling on a similar skyrmion diode system. |
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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 |
000880827900001 |
Publication Date |
2022-10-22 |
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| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.7 |
Times cited |
|
Open Access |
OpenAccess |
|
| |
Notes |
|
Approved |
Most recent IF: 2.7; 2023 IF: 2.649 |
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| |
Call Number |
UA @ admin @ c:irua:192031 |
Serial |
7320 |
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| Permanent link to this record |
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| |
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Author |
Soenen, M.; Bacaksiz, C.; Menezes, R.M.; Milošević, M.V. |
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| |
Title |
Stacking-dependent topological magnons in bilayer CrI₃ |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Physical review materials |
Abbreviated Journal |
|
|
| |
Volume |
7 |
Issue |
2 |
Pages |
024421-10 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
Motivated by the potential of atomically thin magnets towards achieving tunable high-frequency magnonics, we detail the spin-wave dispersion of bilayer CrI3. We demonstrate that the magnonic behavior of the bilayer strongly depends on its stacking configuration and the interlayer magnetic ordering, where a topological band gap opens in the dispersion caused by the Dzyaloshinskii-Moriya and Kitaev interactions, classifying bilayer CrI3 as a topological magnon insulator. We further reveal that both the size and the topology of the band gap in a CrI3 bilayer with an antiferromagnetic interlayer ordering are tunable by an external magnetic field. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
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Editor |
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| |
Language |
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Wos |
000943169600001 |
Publication Date |
2023-02-28 |
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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 |
2475-9953 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.4 |
Times cited |
|
Open Access |
OpenAccess |
|
| |
Notes |
|
Approved |
Most recent IF: 3.4; 2023 IF: NA |
|
| |
Call Number |
UA @ admin @ c:irua:195179 |
Serial |
7338 |
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| Permanent link to this record |
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Author |
Smeyers, R.; Milošević, M.V.; Covaci, L. |
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| |
Title |
Strong gate-tunability of flat bands in bilayer graphene due to moiré encapsulation between hBN monolayers |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Nanoscale |
Abbreviated Journal |
|
|
| |
Volume |
15 |
Issue |
9 |
Pages |
4561-4569 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
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Abstract |
When using hexagonal boron-nitride (hBN) as a substrate for graphene, the resulting moire pattern creates secondary Dirac points. By encapsulating a multilayer graphene within aligned hBN sheets the controlled moire stacking may offer even richer benefits. Using advanced tight-binding simulations on atomistically-relaxed heterostructures, here we show that the gap at the secondary Dirac point can be opened in selected moire-stacking configurations, and is independent of any additional vertical gating of the heterostructure. On the other hand, gating can broadly tune the gap at the principal Dirac point, and may thereby strongly compress the first moire mini-band in width against the moire-induced gap at the secondary Dirac point. We reveal that in hBN-encapsulated bilayer graphene this novel mechanism can lead to isolated bands flatter than 10 meV under moderate gating, hence presenting a convenient pathway towards electronically-controlled strongly-correlated states on demand. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
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Editor |
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Language |
|
Wos |
000933052600001 |
Publication Date |
2023-02-07 |
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| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2040-3364; 2040-3372 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
6.7 |
Times cited |
|
Open Access |
OpenAccess |
|
| |
Notes |
|
Approved |
Most recent IF: 6.7; 2023 IF: 7.367 |
|
| |
Call Number |
UA @ admin @ c:irua:195249 |
Serial |
7340 |
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| Permanent link to this record |
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| |
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Author |
Miranda, L.P.; da Costa, D.R.; Peeters, F.M.; Costa Filho, R.N. |
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Title |
Vacancy clustering effect on the electronic and transport properties of bilayer graphene nanoribbons |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Nanotechnology |
Abbreviated Journal |
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|
| |
Volume |
34 |
Issue |
5 |
Pages |
055706-55710 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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| |
Abstract |
Experimental realizations of two-dimensional materials are hardly free of structural defects such as e.g. vacancies, which, in turn, modify drastically its pristine physical defect-free properties. In this work, we explore effects due to point defect clustering on the electronic and transport properties of bilayer graphene nanoribbons, for AA and AB stacking and zigzag and armchair boundaries, by means of the tight-binding approach and scattering matrix formalism. Evident vacancy concentration signatures exhibiting a maximum amplitude and an universality regardless of the system size, stacking and boundary types, in the density of states around the zero-energy level are observed. Our results are explained via the coalescence analysis of the strong sizeable vacancy clustering effect in the system and the breaking of the inversion symmetry at high vacancy densities, demonstrating a similar density of states for two equivalent degrees of concentration disorder, below and above the maximum value. |
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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 |
|
Wos |
000886630000001 |
Publication Date |
2022-11-02 |
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| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
0957-4484 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.5 |
Times cited |
|
Open Access |
OpenAccess |
|
| |
Notes |
|
Approved |
Most recent IF: 3.5; 2023 IF: 3.44 |
|
| |
Call Number |
UA @ admin @ c:irua:192030 |
Serial |
7350 |
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| Permanent link to this record |
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Author |
Andelkovic, M.; Rakhimov, K.Y.; Chaves, A.; Berdiyorov, G.R.; Milošević, M.V. |
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| |
Title |
Wave-packet propagation in a graphene geometric diode |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Physica. E: Low-dimensional systems and nanostructures |
Abbreviated Journal |
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| |
Volume |
147 |
Issue |
|
Pages |
115607-4 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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| |
Abstract |
Dynamics of electron wave-packets is studied using the continuum Dirac model in a graphene geometric diode where the propagation of the wave packet is favored in certain direction due to the presence of geometric constraints. Clear rectification is obtained in the THz frequency range with the maximum rectification level of 3.25, which is in good agreement with recent experiments on graphene ballistic diodes. The rectification levels are considerably higher for systems with narrower channels. In this case, the wave packet transmission probabilities and rectification rate also strongly depend on the energy of the incident wave packet, as a result of the quantum nature of energy levels along such channels. These findings can be useful for fundamental understanding of the charge carrier dynamics in graphene geometry diodes. |
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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 |
000903737000003 |
Publication Date |
2022-12-10 |
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| |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
1386-9477 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.3 |
Times cited |
1 |
Open Access |
OpenAccess |
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| |
Notes |
|
Approved |
Most recent IF: 3.3; 2023 IF: 2.221 |
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| |
Call Number |
UA @ admin @ c:irua:193497 |
Serial |
7351 |
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| Permanent link to this record |
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Author |
Zhang, G.; Huang, S.; Chaves, A.; Yan, H. |
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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 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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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. |
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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 |
000953463300001 |
Publication Date |
2023-03-13 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
1936-0851 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
17.1 |
Times cited |
|
Open Access |
Not_Open_Access |
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| |
Notes |
|
Approved |
Most recent IF: 17.1; 2023 IF: 13.942 |
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| |
Call Number |
UA @ admin @ c:irua:196100 |
Serial |
7565 |
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| Permanent link to this record |
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Author |
Torun, E.; Paleari, F.; Milošević, M.V.; Wirtz, L.; Sevik, C. |
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Title |
Intrinsic control of interlayer exciton generation in Van der Waals materials via Janus layers |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Nano letters |
Abbreviated Journal |
|
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| |
Volume |
23 |
Issue |
8 |
Pages |
3159-3166 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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| |
Abstract |
We demonstrate the possibility of engineering the optical properties of transition metal dichalcogenide heterobilayers when one of the constitutive layers has a Janus structure. We investigate different MoS2@Janus layer combinations using first-principles methods including excitons and exciton-phonon coupling. The direction of the intrinsic electric field from the Janus layer modifies the electronic band alignments and, consequently, the energy separation between dark interlayer exciton states and bright in-plane excitons. We find that in-plane lattice vibrations strongly couple the two states, so that exciton-phonon scattering may be a viable generation mechanism for interlayer excitons upon light absorption. In particular, in the case of MoS2@WSSe, the energy separation of the low-lying interlayer exciton from the in-plane exciton is resonant with the transverse optical phonon modes (40 meV). We thus identify this heterobilayer as a prime candidate for efficient generation of charge-separated electron-hole pairs. |
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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 |
000969732100001 |
Publication Date |
2023-04-10 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
1530-6984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
10.8 |
Times cited |
|
Open Access |
OpenAccess |
|
| |
Notes |
|
Approved |
Most recent IF: 10.8; 2023 IF: 12.712 |
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| |
Call Number |
UA @ admin @ c:irua:196034 |
Serial |
8118 |
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| Permanent link to this record |
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Author |
Van Duppen, B.; Tomadin, A.; Grigorenko, A.N.; Polini, M. |
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| |
Title |
Current-induced birefringent absorption and non-reciprocal plasmons in graphene |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
2D materials |
Abbreviated Journal |
2D Mater |
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| |
Volume |
3 |
Issue |
3 |
Pages |
015011 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
We present extensive calculations of the optical and plasmonic properties of a graphene sheet carrying a dc current. By calculating analytically the density-density response function of current-carrying states at finite temperature, we demonstrate that an applied dc current modifies the Pauli blocking mechanism and that absorption acquires a birefringent character with respect to the angle between the in-plane light polarization and current flow. Employing the random phase approximation at finite temperature, we show that graphene plasmons display a degree of non-reciprocity and collimation that can be tuned with the applied current. We discuss the possibility to measure these effects. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Wos |
000373936300031 |
Publication Date |
2016-02-23 |
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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 |
2053-1583 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
6.937 |
Times cited |
5 |
Open Access |
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| |
Notes |
This work was supported by the EC under the Graphene Flagship program (contract no. CNECT- ICT-604391) and MIUR through the program ‘Pro- getti Premiali 2012’ – Project ‘ABNANOTECH’. B.V. D. wishes to thank the Scuola Normale Superiore (Pisa, Italy) for the kind hospitality while this work was carried out and Research Foundation Flanders (FWO- Vl) for a PhD Fellowship. |
Approved |
Most recent IF: 6.937 |
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| |
Call Number |
c:irua:131900 c:irua:131900 |
Serial |
4017 |
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| Permanent link to this record |
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Author |
Leenaerts, O.; Vercauteren, S.; Schoeters, B.; Partoens, B. |
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| |
Title |
System-size dependent band alignment in lateral two-dimensional heterostructures |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
2D materials |
Abbreviated Journal |
2D Mater |
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| |
Volume |
3 |
Issue |
3 |
Pages |
025012 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
The electronic band alignment in semiconductor heterostructures is a key factor for their use in electronic applications. The alignment problem has been intensively studied for bulk systems but is less well understood for low-dimensional heterostructures. In this work we investigate the alignment in two-dimensional lateral heterostructures. First-principles calculations are used to show that the electronic band offset depends crucially on the width and thickness of the heterostructure slab. The particular heterostructures under study consist of thin hydrogenated and fluorinated diamond slabs which are laterally joined together. Two different limits for the band offset are observed. For infinitely wide heterostructures the vacuum potential above the two materials is aligned leading to a large step potential within the heterostructure. For infinitely thick heterostructure slabs, on the other hand, there is no potential step in the heterostructure bulk, but a large potential step in the vacuum region above the heterojunction is observed. The band alignment in finite systems depends on the particular dimensions of the system. These observations are shown to result from an interface dipole at the heterojunction that tends to align the band structures. |
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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 |
000378571400032 |
Publication Date |
2016-04-13 |
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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 |
2053-1583 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
6.937 |
Times cited |
19 |
Open Access |
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| |
Notes |
This work was supported by the Fonds Wetenschappelijk Onderzoek (FWO-Vl). The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Hercules Foundation and the Flemish Government— department EWI. |
Approved |
Most recent IF: 6.937 |
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| |
Call Number |
c:irua:132792 c:irua:132792 |
Serial |
4055 |
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| Permanent link to this record |
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Author |
Ozaydin, H.D.; Sahin, H.; Kang, J.; Peeters, F.M.; Senger, R.T. |
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Title |
Electronic and magnetic properties of 1T-TiSe2 nanoribbons |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
2D materials |
Abbreviated Journal |
2D Mater |
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| |
Volume |
2 |
Issue |
2 |
Pages |
044002 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Motivated by the recent synthesis of single layer TiSe2, we used state-of-the-art density functional theory calculations, to investigate the structural and electronic properties of zigzag and armchair-edged nanoribbons (NRs) of this material. Our analysis reveals that, differing from ribbons of other ultra-thin materials such as graphene, TiSe2 NRs have some distinctive properties. The electronic band gap of the NRs decreases exponentially with the width and vanishes for ribbons wider than 20 angstrom. For ultranarrow zigzag-edged NRs we find odd-even oscillations in the band gap width, although their band structures show similar features. Moreover, our detailed magnetic-ground-state analysis reveals that zigzag and armchair edged ribbons have non-magnetic ground states. Passivating the dangling bonds with hydrogen at the edges of the structures influences the band dispersion. Our results shed light on the characteristic properties of T phase NRs of similar crystal structures. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
IOP Publishing |
Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000368936600005 |
Publication Date |
2015-10-13 |
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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 |
2053-1583 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
6.937 |
Times cited |
20 |
Open Access |
|
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| |
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 ULAK-BIM, 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. HDO, HS and RTS acknowledge the support from TUBITAK through project 114F397. ; |
Approved |
Most recent IF: 6.937; 2015 IF: NA |
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Call Number |
UA @ lucian @ c:irua:131602 |
Serial |
4169 |
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| Permanent link to this record |
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Author |
Van der Donck, M.; De Beule, C.; Partoens, B.; Peeters, F.M.; Van Duppen, B. |
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Title |
Piezoelectricity in asymmetrically strained bilayer graphene |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
2D materials |
Abbreviated Journal |
2D Mater |
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| |
Volume |
3 |
Issue |
3 |
Pages |
035015 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We study the electronic properties of commensurate faulted bilayer graphene by diagonalizing the one-particle Hamiltonian of the bilayer system in a complete basis of Bloch states of the individual graphene layers. Our novel approach is very general and can be easily extended to any commensurate graphene-based heterostructure. Here, we consider three cases: (i) twisted bilayer graphene, (ii) bilayer graphene where triaxial stress is applied to one layer and (iii) bilayer graphene where uniaxial stress is applied to one layer. We show that the resulting superstructures can be divided into distinct classes, depending on the twist angle or the magnitude of the induced strain. The different classes are distinguished from each other by the interlayer coupling mechanism, resulting in fundamentally different low-energy physics. For the cases of triaxial and uniaxial stress, the individual graphene layers tend to decouple and we find significant charge transfer between the layers. In addition, this piezoelectric effect can be tuned by applying a perpendicular electric field. Finally, we show how our approach can be generalized to multilayer systems. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
IOP Publishing |
Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000384072500003 |
Publication Date |
2016-08-31 |
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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 |
2053-1583 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
6.937 |
Times cited |
10 |
Open Access |
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| |
Notes |
; This work was supported by the Research Foundation-Flanders (FWO-Vl) through aspirant research grants to MVDD, CDB, and BVD. ; |
Approved |
Most recent IF: 6.937 |
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| |
Call Number |
UA @ lucian @ c:irua:137203 |
Serial |
4361 |
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| Permanent link to this record |
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Author |
Sevik, C.; Wallbank, J.R.; Gulseren, O.; Peeters, F.M.; Çakir, D. |
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Title |
Gate induced monolayer behavior in twisted bilayer black phosphorus |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
2D materials |
Abbreviated Journal |
2D Mater |
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| |
Volume |
4 |
Issue |
3 |
Pages |
035025 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Optical and electronic properties of black phosphorus strongly depend on the number of layers and type of stacking. Using first-principles calculations within the framework of density functional theory, we investigate the electronic properties of bilayer black phosphorus with an interlayer twist angle of 90 degrees. These calculations are complemented with a simple (k) over right arrow . (p) over right arrow model which is able to capture most of the low energy features and is valid for arbitrary twist angles. The electronic spectrum of 90 degrees twisted bilayer black phosphorus is found to be x-y isotropic in contrast to the monolayer. However x-y anisotropy, and a partial return to monolayer-like behavior, particularly in the valence band, can be induced by an external out-of-plane electric field. Moreover, the preferred hole effective mass can be rotated by 90 degrees simply by changing the direction of the applied electric field. In particular, a +0.4 (-0.4) V angstrom(1) out-of-plane electric field results in a similar to 60% increase in the hole effective mass along the y (x) axis and enhances the m(y)*/m(x)* (m(x)*/m(y)*) ratio as much as by a factor of 40. Our DFT and (k) over right arrow . (p) over right arrow simulations clearly indicate that the twist angle in combination with an appropriate gate voltage is a novel way to tune the electronic and optical properties of bilayer phosphorus and it gives us a new degree of freedom to engineer the properties of black phosphorus based devices. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
IOP Publishing |
Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000406926600001 |
Publication Date |
2017-08-03 |
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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 |
2053-1583 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
6.937 |
Times cited |
13 |
Open Access |
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Notes |
; This work was supported by the bilateral project between the The Scientific and Technological Research Council of Turkey (TUBITAK) and FWO-Flanders, Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TRGrid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. We acknowledge the support from TUBITAK (Grant No. 115F024), ERC Synergy grant Hetero2D and the EU Graphene Flagship Project. We also thank Vladimir Fal'ko for helpful discussions. ; |
Approved |
Most recent IF: 6.937 |
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Call Number |
UA @ lucian @ c:irua:145151 |
Serial |
4717 |
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Author |
Moldovan, D.; Masir, M.R.; Peeters, F.M. |
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Title |
Magnetic field dependence of the atomic collapse state in graphene |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
2D materials |
Abbreviated Journal |
2D Mater |
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Volume |
5 |
Issue |
1 |
Pages |
015017 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
<script type='text/javascript'>document.write(unpmarked('Quantum electrodynamics predicts that heavy atoms (Z \u003E Z(c) approximate to 170) will undergo the process of atomic collapse where electrons sink into the positron continuum and a new family of so-called collapsing states emerges. The relativistic electrons in graphene exhibit the same physics but at a much lower critical charge (Z(c) approximate to 1) which has made it possible to confirm this phenomenon experimentally. However, there exist conflicting predictions on the effect of a magnetic field on atomic collapse. These theoretical predictions are based on the continuum Dirac-Weyl equation, which does not have an exact analytical solution for the interplay of a supercritical Coulomb potential and the magnetic field. Approximative solutions have been proposed, but because the two effects compete on similar energy scales, the theoretical treatment varies depending on the regime which is being considered. These limitations are overcome here by starting from a tight-binding approach and computing exact numerical results. By avoiding special limit cases, we found a smooth evolution between the different regimes. We predict that the atomic collapse effect persists even after the magnetic field is activated and that the critical charge remains unchanged. We show that the atomic collapse regime is characterized: (1) by a series of Landau level anticrossings and (2) by the absence of root B scaling of the Landau levels with regard to magnetic field strength.')); |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
IOP Publishing |
Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000415015000001 |
Publication Date |
2017-10-26 |
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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 |
2053-1583 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.937 |
Times cited |
13 |
Open Access |
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Notes |
; We thank Eva Andrei, Jinhai Mao and Yuhang Jiang for insightful discussions. This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem Funding of the Flemish Government. ; |
Approved |
Most recent IF: 6.937 |
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Call Number |
UA @ lucian @ c:irua:147361UA @ admin @ c:irua:147361 |
Serial |
4884 |
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Author |
Peymanirad, F.; Singh, S.K.; Ghorbanfekr-Kalashami, H.; Novoselov, K.S.; Peeters, F.M.; Neek-Amal, M. |
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Title |
Thermal activated rotation of graphene flake on graphene |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
2D materials |
Abbreviated Journal |
2D Mater |
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Volume |
4 |
Issue |
2 |
Pages |
025015 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The self rotation of a graphene flake over graphite is controlled by the size, initial misalignment and temperature. Using both ab initio calculations and molecular dynamics simulations, we investigate annealing effects on the self rotation of a graphene flake on a graphene substrate. The energy barriers for rotation and drift of a graphene flake over graphene is found to be smaller than 25 meV/atom which is comparable to thermal energy. We found that small flakes (of about similar to 4 nm) are more sensitive to temperature and initial misorientation angles than larger one (beyond 10 nm). The initial stacking configuration of the flake is found to be important for its dynamics and time evolution of misalignment. Large flakes, which are initially in the AA-or AB-stacking state with small misorientation angle, rotate and end up in the AB-stacking configuration. However small flakes can they stay in an incommensurate state specially when the initial misorientation angle is larger than 2 degrees. Our results are in agreement with recent experiments. |
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Corporate Author |
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Thesis |
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Publisher |
IOP Publishing |
Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000424399600005 |
Publication Date |
2017-02-02 |
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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 |
2053-1583 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
6.937 |
Times cited |
16 |
Open Access |
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Notes |
; We would like to acknowledge Annalisa Fasolino and MM van Wijk for providing us with the implemented parameters of REBO-KC [5] in LAMMPS. This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation. ; |
Approved |
Most recent IF: 6.937 |
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Call Number |
UA @ lucian @ c:irua:149364 |
Serial |
4984 |
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Author |
Tiwari, S.; Van de Put, M.L.; Sorée, B.; Vandenberghe, W.G. |
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Title |
Carrier transport in two-dimensional topological insulator nanoribbons in the presence of vacancy defects |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
2D materials |
Abbreviated Journal |
2D Mater |
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Volume |
6 |
Issue |
2 |
Pages |
025011 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Using the non-equilibrium Green's function formalism, we study carrier transport through imperfect two-dimensional (2D) topological insulator (TI) ribbons. In particular, we investigate the effect of vacancy defects on the carrier transport in 2D TI ribbons with hexagonal lattice structure. To account for the random distribution of the vacancy defects, we present a statistical study of varying defect densities by stochastically sampling different defect configurations. We demonstrate that the topological edge states of TI ribbons are fairly robust against a high concentration (up to 2%) of defects. At very high defect densities, we observe an increased inter-edge interaction, mediated by the localisation of the edge states within the bulk region. This effect causes significant back-scattering of the, otherwise protected, edge-states at very high defect concentrations (>2%), resulting in a loss of conduction through the TI ribbon. We discuss how this coherent vacancy scattering can be used to our advantage for the development of TI-based transistors. We find that there is an optimal concentration of vacancies yielding an ON-OFF current ratio of up to two orders of magnitude. Finally, we investigate the importance of spin-orbit coupling on the robustness of the edge states in the TI ribbon and show that increased spin-orbit coupling could further increase the ON-OFF ratio. |
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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 |
000457856400002 |
Publication Date |
2019-01-22 |
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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 |
2053-1583 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
6.937 |
Times cited |
3 |
Open Access |
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| |
Notes |
; This material is based in part upon work supported by the National Science Foundation under Grant Number 1710066. The project or effort depicted was or is sponsored by the Department of Defense, Defense Threat Reduction Agency. The content of the information does not necessarily reflect the position or the policy of the federal government, and no official endorsement should be inferred. This work was supported by imec's Industrial Affiliation Program. ; |
Approved |
Most recent IF: 6.937 |
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| |
Call Number |
UA @ admin @ c:irua:157464 |
Serial |
5198 |
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| Permanent link to this record |
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Author |
Li, L.L.; Partoens, B.; Xu, W.; Peeters, F.M. |
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Title |
Electric-field modulation of linear dichroism and Faraday rotation in few-layer phosphorene |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
2D materials |
Abbreviated Journal |
2D Mater |
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| |
Volume |
6 |
Issue |
1 |
Pages |
015032 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Electro-optical modulators, which use an electric voltage (or an electric field) to modulate a beam of light, are essential elements in present-day telecommunication devices. Using a self-consistent tight-binding approach combined with the standard Kubo formula, we show that the optical conductivity and the linear dichroism of few-layer phosphorene can be modulated by a perpendicular electric field. We find that the field-induced charge screening plays a significant role in modulating the optical conductivity and the linear dichroism. Distinct absorption peaks are induced in the conductivity spectrum due to the strong quantum confinement along the out-of-plane direction and to the field-induced forbidden-to-allowed transitions. The field modulation of the linear dichroism becomes more pronounced with increasing number of phosphorene layers. We also show that the Faraday rotation is present in few-layer phosphorene even in the absence of an external magnetic field. This optical Hall effect is induced by the reduced lattice symmetry of few-layer phosphorene. The Faraday rotation is greatly influenced by the field-induced charge screening and is strongly dependent on the strength of perpendicular electric field and on the number of phosphorene layers. |
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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 |
000454321100002 |
Publication Date |
2018-11-28 |
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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 |
2053-1583 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
6.937 |
Times cited |
19 |
Open Access |
|
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| |
Notes |
; This work was financially supported by the Flemish Science Foundation (FWO-Vl) and by the FLAG-ERA project TRANS-2D-TMD. ; |
Approved |
Most recent IF: 6.937 |
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| |
Call Number |
UA @ admin @ c:irua:156776 |
Serial |
5207 |
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| Permanent link to this record |
