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	Author	Van de Put, M.L.; Vandenberghe, W.G.; Magnus, W.; Sorée, B.; Fischetti, M.V.
	Title	Modeling of inter-ribbon tunneling in graphene			Type	P1 Proceeding
	Year	2015	Publication	18th International Workshop On Computational Electronics (iwce 2015)	Abbreviated Journal
	Volume		Issue		Pages
	Keywords	P1 Proceeding; Condensed Matter Theory (CMT)
	Abstract	The tunneling current between two crossed graphene ribbons is described invoking the empirical pseudopotential approximation and the Bardeen transfer Hamiltonian method. Results indicate that the density of states is the most important factor determining the tunneling current between small (similar to nm) ribbons. The quasi-one dimensional nature of graphene nanoribbons is shown to result in resonant tunneling.
	Address
	Corporate Author				Thesis
	Publisher	Ieee	Place of Publication	New york	Editor
	Language		Wos		Publication Date
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	978-0-692-51523-5	ISBN		Additional Links	UA library record; WoS full record
	Impact Factor		Times cited		Open Access
	Notes				Approved	Most recent IF: NA
	Call Number	UA @ lucian @ c:irua:134997			Serial	4206
Permanent link to this record



	Author	Moors, K.; Sorée, B.; Magnus, W.
	Title	Analytic solution of Ando's surface roughness model with finite domain distribution functions			Type	P1 Proceeding
	Year	2015	Publication	18th International Workshop On Computational Electronics (iwce 2015)	Abbreviated Journal
	Volume		Issue		Pages
	Keywords	P1 Proceeding; Condensed Matter Theory (CMT)
	Abstract	Ando's surface roughness model is applied to metallic nanowires and extended beyond small roughness size and infinite barrier limit approximations for the wavefunction overlaps, such as the Prange-Nee approximation. Accurate and fast simulations can still be performed without invoking these overlap approximations by averaging over roughness profiles using finite domain distribution functions to obtain an analytic solution for the scattering rates. The simulations indicate that overlap approximations, while predicting a resistivity that agrees more or less with our novel approach, poorly estimate the underlying scattering rates. All methods show that a momentum gap between left- and right-moving electrons at the Fermi level, surpassing a critical momentum gap, gives rise to a substantial decrease in resistivity.
	Address
	Corporate Author				Thesis
	Publisher	Ieee	Place of Publication	New york	Editor
	Language		Wos		Publication Date
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	978-0-692-51523-5	ISBN		Additional Links	UA library record; WoS full record
	Impact Factor		Times cited		Open Access
	Notes				Approved	Most recent IF: NA
	Call Number	UA @ lucian @ c:irua:134996			Serial	4140
Permanent link to this record



	Author	Moors, K.; Sorée, B.; Magnus, W.
	Title	Modeling and tackling resistivity scaling in metal nanowires			Type	P1 Proceeding
	Year	2015	Publication	International Conference on Simulation of Semiconductor Processes and Devices : [proceedings] T2 – International Conference on Simulation of Semiconductor Processes and, Devices (SISPAD), SEP 09-11, 2015, Washington, DC	Abbreviated Journal
	Volume		Issue		Pages	222-225
	Keywords	P1 Proceeding; Condensed Matter Theory (CMT)
	Abstract	A self-consistent analytical solution of the multi-subband Boltzmann transport equation with collision term describing grain boundary and surface roughness scattering is presented to study the resistivity scaling in metal nanowires. The different scattering mechanisms and the influence of their statistical parameters are analyzed. Instead of a simple power law relating the height or width of a nanowire to its resistivity, the picture appears to be more complicated due to quantum-mechanical scattering and quantization effects, especially for surface roughness scattering.
	Address
	Corporate Author				Thesis
	Publisher	Ieee	Place of Publication	New york	Editor
	Language		Wos		Publication Date
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	978-1-4673-7860-4	ISBN		Additional Links	UA library record; WoS full record
	Impact Factor		Times cited		Open Access
	Notes				Approved	Most recent IF: NA
	Call Number	UA @ lucian @ c:irua:135046			Serial	4205
Permanent link to this record



	Author	Reyntjens, P.D.; Tiwari, S.; van de Put, M.L.; Sorée, B.; Vandenberghe, W.G.
	Title	Ab-initio study of magnetically intercalated platinum diselenide : the impact of platinum vacancies			Type	A1 Journal article
	Year	2021	Publication	Materials	Abbreviated Journal	Materials
	Volume	14	Issue	15	Pages	4167
	Keywords	A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
	Abstract	We study the magnetic properties of platinum diselenide (PtSe2) intercalated with Ti, V, Cr, and Mn, using first-principle density functional theory (DFT) calculations and Monte Carlo (MC) simulations. First, we present the equilibrium position of intercalants in PtSe2 obtained from the DFT calculations. Next, we present the magnetic groundstates for each of the intercalants in PtSe2 along with their critical temperature. We show that Ti intercalants result in an in-plane AFM and out-of-plane FM groundstate, whereas Mn intercalant results in in-plane FM and out-of-plane AFM. V intercalants result in an FM groundstate both in the in-plane and the out-of-plane direction, whereas Cr results in an AFM groundstate both in the in-plane and the out-of-plane direction. We find a critical temperature of <0.01 K, 111 K, 133 K, and 68 K for Ti, V, Cr, and Mn intercalants at a 7.5% intercalation, respectively. In the presence of Pt vacancies, we obtain critical temperatures of 63 K, 32 K, 221 K, and 45 K for Ti, V, Cr, and Mn-intercalated PtSe2, respectively. We show that Pt vacancies can change the magnetic groundstate as well as the critical temperature of intercalated PtSe2, suggesting that the magnetic groundstate in intercalated PtSe2 can be controlled via defect engineering.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000682047700001	Publication Date	2021-07-27
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1996-1944	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.654	Times cited		Open Access	OpenAccess
	Notes				Approved	Most recent IF: 2.654
	Call Number	UA @ admin @ c:irua:180540			Serial	6966
Permanent link to this record



	Author	Verreck, D.; Verhulst, A.S.; Van de Put, M.L.; Sorée, B.; Collaert, N.; Mocuta, A.; Thean, A.; Groeseneken, G.
	Title	Uniform strain in heterostructure tunnel field-effect transistors			Type	A1 Journal article
	Year	2016	Publication	IEEE electron device letters	Abbreviated Journal	Ieee Electr Device L
	Volume	37	Issue	37	Pages	337-340
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Strain can strongly impact the performance of III-V tunnel field-effect transistors (TFETs). However, previous studies on homostructure TFETs have found an increase in ON-current to be accompanied with a degradation of subthreshold swing. We perform 30-band quantum mechanical simulations of staggered heterostructure p-n-i-n TFETs submitted to uniaxial and biaxial uniform stress and find the origin of the subthreshold degradation to be a reduction of the density of states in the strained case. We apply an alternative configuration including a lowly doped pocket in the source, which allows to take full benefit of the strain-induced increase in ON-current.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000372372100026	Publication Date	2016-01-27
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0741-3106	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.048	Times cited	17	Open Access
	Notes	; This work was supported by the imec Industrial Affiliation Program. The work of D. Verreck was supported by the Agency for Innovation by Science and Technology in Flanders. The review of this letter was arranged by Editor Z. Chen. ;			Approved	Most recent IF: 3.048
	Call Number	UA @ lucian @ c:irua:133207			Serial	4271
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	Author	Bizindavyi, J.; Verhulst, A.S.; Smets, Q.; Verreck, D.; Sorée, B.; Groeseneken, G.
	Title	Band-Tails Tunneling Resolving the Theory-Experiment Discrepancy in Esaki Diodes			Type	A1 Journal article
	Year	2018	Publication	IEEE journal of the Electron Devices Society	Abbreviated Journal	Ieee J Electron Devi
	Volume	6	Issue	1	Pages	633-641
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Discrepancies exist between the theoretically predicted and experimentally measured performance of band-to-band tunneling devices, such as Esaki diodes and tunnel field-effect transistors (TFETs). We resolve this discrepancy for highly-doped, direct-bandgap Esaki diodes by successfully calibrating a semi-classical model for high-doping-induced ballistic band-tails tunneling currents at multiple temperatures with two In0.53Ga0.47As Esaki diodes using their SIMS doping profiles, C-V characteristics and their forward-bias current density in the negative differential resistance (NDR) regime. The current swing in the NDR regime is shown not to be linked to the band-tails Urbach energy. We further demonstrate theoretically that the calibrated band-tails contribution is also the dominant band-tails contribution to the subthreshold swing of the corresponding TFETs. Lastly, we verify that the presented procedure is applicable to all direct-bandgap semiconductors by successfully applying it to InAs Esaki diodes in literature.
	Address
	Corporate Author				Thesis
	Publisher	IEEE, Electron Devices Society	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000435505000013	Publication Date	2018-05-15
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2168-6734	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.141	Times cited	5	Open Access
	Notes	; J. Bizindavyi gratefully acknowledges FWO-Vlaanderen for a Strategic Basic Research PhD fellowship. ;			Approved	Most recent IF: 3.141
	Call Number	UA @ lucian @ c:irua:152097UA @ admin @ c:irua:152097			Serial	5014
Permanent link to this record



	Author	Verreck, D.; Van de Put, M.L.; Verhulst, A.S.; Sorée, B.; Magnus, W.; Dabral, A.; Thean, A.; Groeseneken, G.
	Title	15-band spectral envelope function formalism applied to broken gap tunnel field-effect transistors			Type	P1 Proceeding
	Year	2015	Publication	18th International Workshop On Computational Electronics (iwce 2015)	Abbreviated Journal
	Volume		Issue		Pages
	Keywords	P1 Proceeding; Condensed Matter Theory (CMT)
	Abstract	A carefully chosen heterostructure can significantly boost the performance of tunnel field-effect transistors (TFET). Modelling of these hetero-TFETs requires a quantum mechanical (QM) approach with an accurate band structure to allow for a correct description of band-to-band-tunneling. We have therefore developed a fully QM 2D solver, combining for the first time a full zone 15-band envelope function formalism with a spectral approach, including a heterostructure basis set transformation. Simulations of GaSb/InAs broken gap TFETs illustrate the wide body capabilities and transparant transmission analysis of the formalism.
	Address
	Corporate Author				Thesis
	Publisher	Ieee	Place of Publication	New york	Editor
	Language		Wos	000380398200055	Publication Date	2015-10-26
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	978-0-692-51523-5	ISBN		Additional Links	UA library record; WoS full record
	Impact Factor		Times cited		Open Access
	Notes				Approved	Most recent IF: NA
	Call Number	UA @ lucian @ c:irua:134998			Serial	4131
Permanent link to this record



	Author	Tiwari, S.; Vanherck, J.; Van de Put, M.L.; Vandenberghe, W.G.; Sorée, B.
	Title	Computing Curie temperature of two-dimensional ferromagnets in the presence of exchange anisotropy			Type	A1 Journal article
	Year	2021	Publication	Physical review research	Abbreviated Journal
	Volume	3	Issue	4	Pages	043024
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	We compare three first-principles methods of calculating the Curie temperature in two-dimensional (2D) ferromagnetic materials (FM), modeled using the Heisenberg model, and propose a simple formula for estimating the Curie temperature with high accuracy that works for all common 2D lattice types. First, we study the effect of exchange anisotropy on the Curie temperature calculated using the Monte Carlo (MC), the Green's function, and the renormalized spin-wave (RNSW) methods. We find that the Green's function method overestimates the Curie temperature in high-anisotropy regimes compared to the MC method, whereas the RNSW method underestimates the Curie temperature compared to the MC and the Green's function methods. Next, we propose a closed-form formula for calculating the Curie temperature of 2D FMs, which provides an estimate of the Curie temperature that is greatly improved over the mean-field expression for magnetic material screening. We apply the closed-form formula to predict the Curie temperature 2D magnets screened from the C2DB database and discover several high Curie temperature FMs, with Fe2F2 and MoI2 emerging as the most promising 2D ferromagnets. Finally, by comparing to experimental results for CrI3, CrCl3, and CrBr3, we conclude that for small effective anisotropies, the Green's-function-based equations are preferable, while for larger anisotropies, MC-based results are more predictive.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000707506500001	Publication Date	2021-10-11
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN		ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor		Times cited		Open Access	OpenAccess
	Notes				Approved	Most recent IF: NA
	Call Number	UA @ admin @ c:irua:182522			Serial	6975
Permanent link to this record



	Author	Moors, K.; Contino, A.; Van de Put, M.L.; Vandenberghe, W.G.; Fischetti, M., V; Magnus, W.; Sorée, B.
	Title	Theoretical study of scattering in graphene ribbons in the presence of structural and atomistic edge roughness			Type	A1 Journal article
	Year	2019	Publication	Physical review materials	Abbreviated Journal
	Volume	3	Issue	2	Pages	024001
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	We investigate the diffusive electron-transport properties of charge-doped graphene ribbons and nanoribbons with imperfect edges. We consider different regimes of edge scattering, ranging from wide graphene ribbons with (partially) diffusive edge scattering to ribbons with large width variations and nanoribbons with atomistic edge roughness. For the latter, we introduce an approach based on pseudopotentials, allowing for an atomistic treatment of the band structure and the scattering potential, on the self-consistent solution of the Boltzmann transport equation within the relaxation-time approximation and taking into account the edge-roughness properties and statistics. The resulting resistivity depends strongly on the ribbon orientation, with zigzag (armchair) ribbons showing the smallest (largest) resistivity and intermediate ribbon orientations exhibiting intermediate resistivity values. The results also show clear resistivity peaks, corresponding to peaks in the density of states due to the confinement-induced subband quantization, except for armchair-edge ribbons that show a very strong width dependence because of their claromatic behavior. Furthermore, we identify a strong interplay between the relative position of the two valleys of graphene along the transport direction, the correlation profile of the atomistic edge roughness, and the chiral valley modes, leading to a peculiar strongly suppressed resistivity regime, most pronounced for the zigzag orientation.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000458161800001	Publication Date	2019-02-06
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2475-9953	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor		Times cited	4	Open Access
	Notes	; We acknowledge the Research Foundation – Flanders (FWO) for supporting K.M.'s research visit at the University of Texas at Dallas, as well as the support by the National Research Fund Luxembourg (FNR) with ATTRACT Grant No. 7556175. ;			Approved	Most recent IF: NA
	Call Number	UA @ admin @ c:irua:157499			Serial	5235
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	Author	De Clercq, M.; Moors, K.; Sankaran, K.; Pourtois, G.; Dutta, S.; Adelmann, C.; Magnus, W.; Sorée, B.
	Title	Resistivity scaling model for metals with conduction band anisotropy			Type	A1 Journal article
	Year	2018	Publication	Physical review materials	Abbreviated Journal
	Volume	2	Issue	3	Pages	033801
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	It is generally understood that the resistivity of metal thin films scales with film thickness mainly due to grain boundary and boundary surface scattering. Recently, several experiments and ab initio simulations have demonstrated the impact of crystal orientation on resistivity scaling. The crystal orientation cannot be captured by the commonly used resistivity scaling models and a qualitative understanding of its impact is currently lacking. In this work, we derive a resistivity scaling model that captures grain boundary and boundary surface scattering as well as the anisotropy of the band structure. The model is applied to Cu and Ru thin films, whose conduction bands are (quasi-) isotropic and anisotropic, respectively. After calibrating the anisotropy with ab initio simulations, the resistivity scaling models are compared to experimental resistivity data and a renormalization of the fitted grain boundary reflection coefficient can be identified for textured Ru.
	Address
	Corporate Author				Thesis
	Publisher	American Physical Society	Place of Publication	College Park, Md	Editor
	Language		Wos	000426787600001	Publication Date	2018-03-07
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2475-9953	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor		Times cited		Open Access
	Notes	; The authors acknowledge the support by the Fonds National de la Recherche Luxembourg (ATTRACT Grant No. 7556175). ;			Approved	Most recent IF: NA
	Call Number	UA @ lucian @ c:irua:149866UA @ admin @ c:irua:149866			Serial	4947
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	Author	Pourghaderi, M.A.; Magnus, W.; Sorée, B.; Meuris, M.; de Meyer, K.; Heyns, M.
	Title	Tunneling-lifetime model for metal-oxide-semiconductor structures			Type	A1 Journal article
	Year	2009	Publication	Physical review : B : solid state	Abbreviated Journal	Phys Rev B
	Volume	80	Issue	8	Pages	085315,1-085315,10
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	In this paper we investigate the basic physics of charge carriers (electrons) leaking out of the inversion layer of a metal-oxide-semiconductor capacitor with a biased gate. In particular, we treat the gate leakage current as resulting from two combined processes: (1) the time-dependent decay of electron wave packets representing the inversion-layer charge and (2) the local generation of new electrons replacing those that have leaked away. As a result, the gate current simply emerges as the ratio of the total charge in the inversion layer to the tunneling lifetime. The latter is extracted from the quantum dynamics of the decaying wave packets, while the generation rate is incorporated as a phenomenological source term in the continuity equation. Not only do the gate currents calculated with this model agree very well with experiment, the model also provides an onset to solve the paradox of the current-free bound states representing the resonances of the Schrödinger equation that governs the fully coupled metal-oxide-semiconductor system.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Lancaster, Pa	Editor
	Language		Wos	000269639300076	Publication Date	2009-08-21
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1098-0121;1550-235X;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.836	Times cited	2	Open Access
	Notes				Approved	Most recent IF: 3.836; 2009 IF: 3.475
	Call Number	UA @ lucian @ c:irua:78294			Serial	3763
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	Author	van Duijn, F.; Osca, J.; Sorée, B.
	Title	Skyrmion elongation, duplication, and rotation by spin-transfer torque under spatially varying spin current			Type	A1 Journal article
	Year	2021	Publication	Physical Review B	Abbreviated Journal	Phys Rev B
	Volume	104	Issue	9	Pages	094426
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	The effect of the spatially varying spin current on a skyrmion is numerically investigated. It is shown that an inhomogeneous current density induces an elongation of the skyrmion. This elongation can be controlled using current pulses of different strength and duration. Long current pulses lead to a splitting that forms two replicas of the initial skyrmion while for short pulses the elongated skyrmion relaxes back to its initial circular state through rotation in the MHz-GHz frequency range. The frequency is dependent on the strength of the damping coefficient.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000704236000002	Publication Date	2021-09-21
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2469-9969; 2469-9950	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.836	Times cited		Open Access	OpenAccess
	Notes				Approved	Most recent IF: 3.836
	Call Number	UA @ admin @ c:irua:182467			Serial	7018
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	Author	Vanderveken, F.; Mulkers, J.; Leliaert, J.; Van Waeyenberge, B.; Sorée, B.; Zografos, O.; Ciubotaru, F.; Adelmann, C.
	Title	Confined magnetoelastic waves in thin waveguides			Type	A1 Journal article
	Year	2021	Publication	Physical Review B	Abbreviated Journal	Phys Rev B
	Volume	103	Issue	5	Pages	054439
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	The characteristics of confined magnetoelastic waves in nanoscale ferromagnetic magnetostrictive waveguides have been investigated by a combination of analytical and numerical calculations. The presence of both magnetostriction and inverse magnetostriction leads to the coupling between confined spin waves and elastic Lamb waves. Numerical simulations of the coupled system have been used to extract the dispersion relations of the magnetoelastic waves as well as their mode profiles.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000627548800003	Publication Date	2021-02-26
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2469-9969; 2469-9950	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.836	Times cited		Open Access	OpenAccess
	Notes				Approved	Most recent IF: 3.836
	Call Number	UA @ admin @ c:irua:177607			Serial	6976
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	Author	Tiwari, S.; Van de Put, M.L.; Sorée, B.; Vandenberghe, W.G.
	Title	Critical behavior of the ferromagnets CrI₃, CrBr₃, and CrGeTe₃ and the antiferromagnet FeCl₂ : a detailed first-principles study			Type	A1 Journal article
	Year	2021	Publication	Physical Review B	Abbreviated Journal	Phys Rev B
	Volume	103	Issue	1	Pages	014432
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	We calculate the Curie temperature of layered ferromagnets, chromium tri-iodide (CrI3), chromium tri-bromide (CrBr3), chromium germanium tri-telluride (CrGeTe3), and the Ned temperature of a layered antiferromagnet iron di-chloride (FeCl2), using first-principles density functional theory calculations and Monte Carlo simulations. We develop a computational method to model the magnetic interactions in layered magnetic materials and calculate their critical temperature. We provide a unified method to obtain the magnetic exchange parameters (J) for an effective Heisenberg Hamiltonian from first principles, taking into account both the magnetic ansiotropy as well as the out-of-plane interactions. We obtain the magnetic phase change behavior, in particular the critical temperature, from the susceptibility and the specific-heat, calculated using the three-dimensional Monte Carlo (METROPOLIS) algorithm. The calculated Curie temperatures for ferromagnetic materials (CrI3, CrBr3, and CrGeTe3), match well with experimental values. We show that the interlayer interaction in bulk CrI3 with R (3) over bar stacking is significantly stronger than the C2/m stacking, in line with experimental observations. We show that the strong interlayer interaction in R (3) over bar CrI3 results in a competition between the in-plane and the out-of-plane magnetic easy axes. Finally, we calculate the Ned temperature of FeCl2 to be 47 +/- 8 K and show that the magnetic phase transition in FeCl2 occurs in two steps with a high-temperature intralayer ferromagnetic phase transition and a low-temperature interlayer antiferromagnetic phase transition.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000609012000002	Publication Date	2021-01-20
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2469-9969; 2469-9950	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.836	Times cited		Open Access	OpenAccess
	Notes	; The project or effort depicted was or is sponsored by the Department of Defense, Defense Threat Reduction Agency Grant No. HDTRA1-18-1-0018. 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: 3.836
	Call Number	UA @ admin @ c:irua:176081			Serial	6686
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	Author	Devolder, T.; Bultynck, O.; Bouquin, P.; Nguyen, V.D.; Rao, S.; Wan, D.; Sorée, B.; Radu, I.P.; Kar, G.S.; Couet, S.
	Title	Back hopping in spin transfer torque switching of perpendicularly magnetized tunnel junctions			Type	A1 Journal article
	Year	2020	Publication	Physical Review B	Abbreviated Journal	Phys Rev B
	Volume	102	Issue	18	Pages	184406
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	We analyze the phenomenon of back hopping in spin-torque induced switching of the magnetization in perpendicularly magnetized tunnel junctions. The analysis is based on single-shot time-resolved conductance measurements of the pulse-induced back hopping. Studying several material variants reveals that the back hopping is a feature of the nominally fixed system of the tunnel junction. The back hopping is found to proceed by two sequential switching events that lead to a final state P' of conductance close to-but distinct from-that of the conventional parallel state. The P' state does not exist at remanence. It generally relaxes to the conventional antiparallel state if the current is removed. The P' state involves a switching of the sole spin-polarizing part of the fixed layers. The analysis of literature indicates that back hopping occurs only when the spin-polarizing layer is too weakly coupled to the rest of the fixed system, which justifies a posteriori the mitigation strategies of back hopping that were implemented empirically in spin-transfer-torque magnetic random access memories.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000587594900005	Publication Date	2020-11-09
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2469-9969; 2469-9950	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.7	Times cited		Open Access
	Notes	; This work was supported in part by the IMEC's Industrial Affiliation Program on STT-MRAM device, and in part by the imec IIAP core CMOS and the Beyond CMOS program of Intel Corporation. T. D. and P. B. thank Jonathan Z. Sun for constructive discussions on the BH phenomenon. ;			Approved	Most recent IF: 3.7; 2020 IF: 3.836
	Call Number	UA @ admin @ c:irua:173524			Serial	6458
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	Author	Reyntjens, P.D.; Tiwari, S.; van de Put, M.L.; Sorée, B.; Vandenberghe, W.G.
	Title	Magnetic properties and critical behavior of magnetically intercalated WSe₂ : a theoretical study			Type	A1 Journal article
	Year	2021	Publication	2d Materials	Abbreviated Journal	2D Mater
	Volume	8	Issue	2	Pages	025009
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Transition metal dichalcogenides, intercalated with transition metals, are studied for their potential applications as dilute magnetic semiconductors. We investigate the magnetic properties of WSe2 doped with third-row transition metals (Co, Cr, Fe, Mn, Ti and V). Using density functional theory in combination with Monte Carlo simulations, we obtain an estimate of the Curie or Neel temperature. We find that the magnetic ordering is highly dependent on the dopant type. While Ti and Cr-doped WSe2 have a ferromagnetic ground state, V, Mn, Fe and Co-doped WSe2 are antiferromagnetic in their ground state. For Fe doped WSe2, we find a high Curie-temperature of 327 K. In the case of V-doped WSe2, we find that there are two distinct magnetic phase transitions, originating from a frustrated in-plane antiferromagnetic exchange interaction and a ferromagnetic out-of-plane interaction. We calculate the formation energy and reveal that, in contrast to earlier reports, the formation energy is positive for the intercalated systems studied here. We also show that in the presence of W-vacancies, it becomes favorable for Ti, Fe, and Co to intercalate in WSe2.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000601127600001	Publication Date	2020-12-09
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2053-1583	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	6.937	Times cited	1	Open Access	OpenAccess
	Notes	; 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 material is based upon work supported by the National Science Foundation under Grant No. 1802166. Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. This work was supported by IMEC's Industrial Affiliation Program. Peter D Reyntjens acknowledges support by the Eugene McDermott Fellowship program, under Grant Number 201806. ;			Approved	Most recent IF: 6.937
	Call Number	UA @ admin @ c:irua:174951			Serial	6692
Permanent link to this record



	Author	Tiwari, S.; Van de Put, M.L.; Sorée, B.; Vandenberghe, W.G.
	Title	Carrier transport in two-dimensional topological insulator nanoribbons in the presence of vacancy defects			Type	A1 Journal article
	Year	2019	Publication	2D materials	Abbreviated Journal	2D Mater
	Volume	6	Issue	2	Pages	025011
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	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.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000457856400002	Publication Date	2019-01-22
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2053-1583	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	6.937	Times cited	3	Open Access
	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
	Call Number	UA @ admin @ c:irua:157464			Serial	5198
Permanent link to this record



	Author	Magnus, W.; Brosens, F.; Sorée, B.
	Title	Time dependent transport in 1D micro- and nanostructures: solving the Boltzmann and Wigner-Boltzmann equations			Type	A1 Journal article
	Year	2009	Publication	Journal of physics : conference series	Abbreviated Journal
	Volume	193	Issue	1	Pages	012004,1-012004,4
	Keywords	A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
	Abstract	For many decades the Boltzmann distribution function has been used to calculate the non-equilibrium properties of mobile particles undergoing the combined action of various scattering mechanisms and externally applied force fields. When the latter give rise to the occurrence of inhomogeneous potential profiles across the region through which the particles are moving, the numerical solution of the Boltzmann equation becomes a highly complicated task. In this work we highlight a particular algorithm that can be used to solve the time dependent Boltzmann equation as well as its quantum mechanical extension, the WignerBoltzmann equation. As an illustration, we show the calculated distribution function describing electrons propagating under the action of both a uniform and a pronouncedly non-uniform electric field.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Bristol	Editor
	Language		Wos	000277100400004	Publication Date	2009-11-17
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1742-6596;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor		Times cited	2	Open Access
	Notes				Approved	Most recent IF: NA
	Call Number	UA @ lucian @ c:irua:82861			Serial	3667
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	Author	Vanderveken, F.; Ahmad, H.; Heyns, M.; Sorée, B.; Adelmann, C.; Ciubotaru, F.
	Title	Excitation and propagation of spin waves in non-uniformly magnetized waveguides			Type	A1 Journal article
	Year	2020	Publication	Journal Of Physics D-Applied Physics	Abbreviated Journal	J Phys D Appl Phys
	Volume	53	Issue	49	Pages	495006
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	The characteristics of spin waves in ferromagnetic waveguides with non-uniform magnetization have been investigated for situations where the shape anisotropy field of the waveguide is comparable to the external bias field. Spin-wave generation was realized by the magnetoelastic effect by applying normal and shear strain components, as well as by the Oersted field emitted by an inductive antenna. The magnetoelastic excitation field has a non-uniform profile over the width of the waveguide because of the non-uniform magnetization orientation, whereas the Oersted field remains uniform. Using micromagnetic simulations, we indicate that both types of excitation fields generate quantised width modes with both odd and even mode numbers as well as tilted phase fronts. We demonstrate that these effects originate from the average magnetization orientation with respect to the main axes of the magnetic waveguide. Furthermore, it is indicated that the excitation efficiency of the second-order mode generally surpasses that of the first-order mode due to their symmetry. The relative intensity of the excited modes can be controlled by the strain state as well as by tuning the dimensions of the excitation area. Finally, we demonstrate that the nonreciprocity of spin-wave radiation due to the chirality of an Oersted field generated by an inductive antenna is absent for magnetoelastic spin-wave excitation.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000575331600001	Publication Date	2020-08-26
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0022-3727	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.4	Times cited	1	Open Access
	Notes	; This work has been supported by imec's industrial affiliate program on beyond-CMOS logic. It has also received funding from the European Union's Horizon 2020 research and innovation program within the FET-OPEN project CHIRON under grant agreement No. 801055. F V acknowledges financial support from the Research Foundation -Flanders (FWO) through grant No. 1S05719N. ;			Approved	Most recent IF: 3.4; 2020 IF: 2.588
	Call Number	UA @ admin @ c:irua:172641			Serial	6515
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	Author	Vermeulen, B.B.; Raymenants, E.; Pham, V.T.; Pizzini, S.; Sorée, B.; Wostyn, K.; Couet, S.; Nguyen, V.D.; Temst, K.
	Title	Towards fully electrically controlled domain-wall logic			Type	A1 Journal article
	Year	2024	Publication	AIP advances	Abbreviated Journal
	Volume	14	Issue	2	Pages	025030-25035
	Keywords	A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
	Abstract	Utilizing magnetic tunnel junctions (MTJs) for write/read and fast spin-orbit-torque (SOT)-driven domain-wall (DW) motion for propagation, enables non-volatile logic and majority operations, representing a breakthrough in the implementation of nanoscale DW logic devices. Recently, current-driven DW logic gates have been demonstrated via magnetic imaging, where the Dzyaloshinskii-Moriya interaction (DMI) induces chiral coupling between perpendicular magnetic anisotropy (PMA) regions via an in-plane (IP) oriented region. However, full electrical operation of nanoscale DW logic requires electrical write/read operations and a method to pattern PMA and IP regions compatible with the fabrication of PMA MTJs. Here, we study the use of a Hybrid Free Layer (HFL) concept to combine an MTJ stack with DW motion materials, and He+ ion irradiation to convert the stack from PMA to IP. First, we investigate the free layer thickness dependence of 100-nm diameter HFL-MTJ devices and find an optimal CoFeB thickness, from 7 to 10 angstrom, providing high tunneling magnetoresistance (TMR) readout and efficient spin-transfer torque (STT) writing. We then show that high DMI materials, like Pt/Co, can be integrated into an MTJ stack via interlayer exchange coupling with the CoFeB free layer. In this design, DMI values suitable for SOT-driven DW motion are measured by asymmetric bubble expansion. Finally, we demonstrate that He+ irradiation reliably converts the coupled free layers from PMA to IP. These findings offer a path toward the integration of fully electrically controlled DW logic circuits.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	001163573400005	Publication Date	2024-02-16
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2158-3226	ISBN		Additional Links	UA library record; WoS full record
	Impact Factor		Times cited		Open Access
	Notes				Approved	no
	Call Number	UA @ admin @ c:irua:203823			Serial	9109
Permanent link to this record



	Author	Duflou, R.; Ciubotaru, F.; Vaysset, A.; Heyns, M.; Sorée, B.; Radu, I.P.; Adelmann, C.
	Title	Micromagnetic simulations of magnetoelastic spin wave excitation in scaled magnetic waveguides			Type	A1 Journal article
	Year	2017	Publication	Applied physics letters	Abbreviated Journal
	Volume	111	Issue	19	Pages	192411
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	We study the excitation of spin waves in scaled magnetic waveguides using the magnetoelastic effect. In uniformly magnetized systems, normal strains parallel or perpendicular to the magnetization direction do not lead to spin wave excitation since the magnetoelastic torque is zero. Using micromagnetic simulations, we show that the nonuniformity of the magnetization in submicron waveguides due to the effect of the demagnetizing field leads to the excitation of spin waves for oscillating normal strains both parallel and perpendicular to the magnetization. The excitation by biaxial normal in-plane strain was found to be much more efficient than that by uniaxial normal out-of-plane strain. For narrow waveguides with a width of 200 nm, the excitation efficiency of biaxial normal in-plane strain was comparable to that of shear strain. Published by AIP Publishing.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000414975500027	Publication Date	2017-11-10
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0003-6951; 1077-3118	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor		Times cited		Open Access
	Notes				Approved	no
	Call Number	UA @ admin @ c:irua:152599			Serial	8247
Permanent link to this record



	Author	Doevenspeck, J.; Zografos, O.; Gurunarayanan, S.; Lauwereins, R.; Raghavan, P.; Sorée, B.
	Title	Design and simulation of plasmonic interference-based majority gate			Type	A1 Journal article
	Year	2017	Publication	AIP advances	Abbreviated Journal
	Volume	7	Issue	6	Pages	065116
	Keywords	A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
	Abstract	Major obstacles in current CMOS technology, such as the interconnect bottleneck and thermal heat management, can be overcome by employing subwavelength-scaled light in plasmonic waveguides and devices. In this work, a plasmonic structure that implements the majority (MAJ) gate function is designed and thoroughly studied through simulations. The structure consists of three merging waveguides, serving as the MAJ gate inputs. The information of the logic signals is encoded in the phase of transmitted surface plasmon polaritons (SPP). SPPs are excited at all three inputs and the phase of the output SPP is determined by theMAJof the input phases. The operating dimensions are identified and the functionality is verified for all input combinations. This is the first reported simulation of a plasmonic MAJ gate and thus contributes to the field of optical computing at the nanoscale. (C) 2017 Author(s).
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000404621200036	Publication Date	2017-06-23
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2158-3226	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor		Times cited		Open Access
	Notes				Approved	no
	Call Number	UA @ admin @ c:irua:152632			Serial	7764
Permanent link to this record



	Author	Mohammed, M.; Verhulst, A.S.; Verreck, D.; Van de Put, M.; Simoen, E.; Sorée, B.; Kaczer, B.; Degraeve, R.; Mocuta, A.; Collaert, N.; Thean, A.; Groeseneken, G.
	Title	Electric-field induced quantum broadening of the characteristic energy level of traps in semiconductors and oxides			Type	A1 Journal article
	Year	2016	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	120	Issue	120	Pages	245704
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	The trap-assisted tunneling (TAT) current in tunnel field-effect transistors (TFETs) is one of the crucial factors degrading the sub-60 mV/dec sub-threshold swing. To correctly predict the TAT currents, an accurate description of the trap is required. Since electric fields in TFETs typically reach beyond 10(6) V/cm, there is a need to quantify the impact of such high field on the traps. We use a quantum mechanical implementation based on the modified transfer matrix method to obtain the trap energy level. We present the qualitative impact of electric field on different trap configurations, locations, and host materials, including both semiconductors and oxides. We determine that there is an electric-field related trap level shift and level broadening. We find that these electric-field induced quantum effects can enhance the trap emission rates. Published by AIP Publishing.
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000392174000028	Publication Date	2016-12-26
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979; 1089-7550	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.068	Times cited	6	Open Access
	Notes	; This work was supported by imec's Industrial Affiliation Program. D. Verreck acknowledges the support of a PhD stipend from IWT-Vlaanderen. ;			Approved	Most recent IF: 2.068
	Call Number	UA @ lucian @ c:irua:141481			Serial	4593
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	Author	Van de Put, M.L.; Vandenberghe, W.G.; Sorée, B.; Magnus, W.; Fischetti, M.V.
	Title	Inter-ribbon tunneling in graphene: An atomistic Bardeen approach			Type	A1 Journal article
	Year	2016	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	119	Issue	119	Pages	214306
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	A weakly coupled system of two crossed graphene nanoribbons exhibits direct tunneling due to the overlap of the wavefunctions of both ribbons. We apply the Bardeen transfer Hamiltonian formalism, using atomistic band structure calculations to account for the effect of the atomic structure on the tunneling process. The strong quantum-size confinement of the nanoribbons is mirrored by the one-dimensional character of the electronic structure, resulting in properties that differ significantly from the case of inter-layer tunneling, where tunneling occurs between bulk two-dimensional graphene sheets. The current-voltage characteristics of the inter-ribbon tunneling structures exhibit resonance, as well as stepwise increases in current. Both features are caused by the energetic alignment of one-dimensional peaks in the density-of-states of the ribbons. Resonant tunneling occurs if the sign of the curvature of the coupled energy bands is equal, whereas a step-like increase in the current occurs if the signs are opposite. Changing the doping modulates the onset-voltage of the effects as well as their magnitude. Doping through electrostatic gating makes these structures promising for application towards steep slope switching devices. Using the atomistic empirical pseudopotentials based Bardeen transfer Hamiltonian method, inter-ribbon tunneling can be studied for the whole range of two-dimensional materials, such as transition metal dichalcogenides. The effects of resonance and of step-like increases in the current we observe in graphene ribbons are also expected in ribbons made from these alternative two-dimensional materials, because these effects are manifestations of the one-dimensional character of the density-of-states. Published by AIP Publishing.
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000378923100022	Publication Date	2016-06-07
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979; 1089-7550	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.068	Times cited	6	Open Access
	Notes	; ;			Approved	Most recent IF: 2.068
	Call Number	UA @ lucian @ c:irua:134652			Serial	4198
Permanent link to this record



	Author	Andrikopoulos, D.; Sorée, B.; De Boeck, J.
	Title	Skyrmion-induced bound states on the surface of three-dimensional topological insulators			Type	A1 Journal article
	Year	2016	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	119	Issue	119	Pages	193903
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	The interaction between the surface of a 3D topological insulator and a skyrmion/anti-skyrmion structure is studied in order to investigate the possibility of electron confinement due to the skyrmion presence. Both hedgehog (Neel) and vortex (Bloch) skyrmions are considered. For the hedgehog skyrmion, the in-plane components cannot be disregarded and their interaction with the surface state of the topological insulator (TI) has to be taken into account. A semi-classical description of the skyrmion chiral angle is obtained using the variational principle. It is shown that both the hedgehog and the vortex skyrmion can induce bound states on the surface of the TI. However, the number and the properties of these states depend strongly on the skyrmion type and the skyrmion topological number N-Sk. The probability densities of the bound electrons are also derived where it is shown that they are localized within the skyrmion region. Published by AIP Publishing.
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000377718100013	Publication Date	2016-05-18
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979; 1089-7550	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.068	Times cited	8	Open Access
	Notes	; ;			Approved	Most recent IF: 2.068
	Call Number	UA @ lucian @ c:irua:134607			Serial	4244
Permanent link to this record



	Author	Moors, K.; Sorée, B.; Magnus, W.
	Title	Modeling surface roughness scattering in metallic nanowires			Type	A1 Journal article
	Year	2015	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	118	Issue	118	Pages	124307
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Ando's model provides a rigorous quantum-mechanical framework for electron-surface roughness scattering, based on the detailed roughness structure. We apply this method to metallic nanowires and improve the model introducing surface roughness distribution functions on a finite domain with analytical expressions for the average surface roughness matrix elements. This approach is valid for any roughness size and extends beyond the commonly used Prange-Nee approximation. The resistivity scaling is obtained from the self-consistent relaxation time solution of the Boltzmann transport equation and is compared to Prange-Nee's approach and other known methods. The results show that a substantial drop in resistivity can be obtained for certain diameters by achieving a large momentum gap between Fermi level states with positive and negative momentum in the transport direction. (C) 2015 AIP Publishing LLC.
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000362565800032	Publication Date	2015-09-24
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979; 1089-7550	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.068	Times cited	11	Open Access
	Notes	; ;			Approved	Most recent IF: 2.068; 2015 IF: 2.183
	Call Number	UA @ lucian @ c:irua:129425			Serial	4207
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	Author	Moors, K.; Sorée, B.; Tokei, Z.; Magnus, W.
	Title	Resistivity scaling and electron relaxation times in metallic nanowires			Type	A1 Journal article
	Year	2014	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	116	Issue	6	Pages	063714
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	We study the resistivity scaling in nanometer-sized metallic wires due to surface roughness and grain-boundaries, currently the main cause of electron scattering in nanoscaled interconnects. The resistivity has been obtained with the Boltzmann transport equation, adopting the relaxation time approximation of the distribution function and the effective mass approximation for the conducting electrons. The relaxation times are calculated exactly, using Fermi's golden rule, resulting in a correct relaxation time for every sub-band state contributing to the transport. In general, the relaxation time strongly depends on the sub-band state, something that remained unclear with the methods of previous work. The resistivity scaling is obtained for different roughness and grain-boundary properties, showing large differences in scaling behavior and relaxation times. Our model clearly indicates that the resistivity is dominated by grain-boundary scattering, easily surpassing the surface roughness contribution by a factor of 10. (C) 2014 AIP Publishing LLC.
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000341179400036	Publication Date	2014-08-15
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979;1089-7550;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.068	Times cited	17	Open Access
	Notes	; ;			Approved	Most recent IF: 2.068; 2014 IF: 2.183
	Call Number	UA @ lucian @ c:irua:119260			Serial	2882
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	Author	Verhulst, A.S.; Verreck, D.; Pourghaderi, M.A.; Van de Put, M.; Sorée, B.; Groeseneken, G.; Collaert, N.; Thean, A.V.-Y.
	Title	Can p-channel tunnel field-effect transistors perform as good as n-channel?			Type	A1 Journal article
	Year	2014	Publication	Applied physics letters	Abbreviated Journal	Appl Phys Lett
	Volume	105	Issue	4	Pages	043103
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	We show that bulk semiconductor materials do not allow perfectly complementary p- and n-channel tunnel field-effect transistors (TFETs), due to the presence of a heavy-hole band. When tunneling in p-TFETs is oriented towards the gate-dielectric, field-induced quantum confinement results in a highest-energy subband which is heavy-hole like. In direct-bandgap IIIV materials, the most promising TFET materials, phonon-assisted tunneling to this subband degrades the subthreshold swing and leads to at least 10x smaller on-current than the desired ballistic on-current. This is demonstrated with quantum-mechanical predictions for p-TFETs with tunneling orthogonal to the gate, made out of InP, In0.53Ga0.47As, InAs, and a modified version of In0.53Ga0.47As with an artificially increased conduction-band density-of-states. We further show that even if the phonon-assisted current would be negligible, the build-up of a heavy-hole-based inversion layer prevents efficient ballistic tunneling, especially at low supply voltages. For p-TFET, a strongly confined n-i-p or n-p-i-p configuration is therefore recommended, as well as a tensily strained line-tunneling configuration. (C) 2014 AIP Publishing LLC.
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000341152600067	Publication Date	2014-07-30
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0003-6951; 1077-3118	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.411	Times cited	8	Open Access
	Notes	; This work was supported by imec's industrial application program. D. Verreck acknowledges the support of a Ph.D. stipend from the Institute for Promotion of Innovation through Science and Technology in Flanders (IWT). ;			Approved	Most recent IF: 3.411; 2014 IF: 3.302
	Call Number	UA @ lucian @ c:irua:134433			Serial	4587
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	Author	Sorée, B.; Magnus, W.; Vandenberghe, W.
	Title	Low-field mobility in ultrathin silicon nanowire junctionless transistors			Type	A1 Journal article
	Year	2011	Publication	Applied physics letters	Abbreviated Journal	Appl Phys Lett
	Volume	99	Issue	23	Pages	233509-233509,3
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	We theoretically investigate the phonon, surface roughness and ionized impurity limited low-field mobility of ultrathin silicon n-type nanowire junctionless transistors in the long channel approximation with wire radii ranging from 2 to 5 nm, as function of gate voltage. We show that surface roughness scattering is negligible as long as the wire radius is not too small and ionized impurity scattering is the dominant scattering mechanism. We also show that there exists an optimal radius where the ionized impurity limited mobility exhibits a maximum.
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000298006100095	Publication Date	2011-12-09
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0003-6951;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.411	Times cited	20	Open Access
	Notes	; This work is supported by the EU project SQWIRE (FP7-ICT-STREP nr. 257111). William Vandenberghe gratefully acknowledges the Ph.D. stipend from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen). ;			Approved	Most recent IF: 3.411; 2011 IF: 3.844
	Call Number	UA @ lucian @ c:irua:92865			Serial	1850
Permanent link to this record



	Author	Bizindavyi, J.; Verhulst, A.S.; Sorée, B.; Vandenberghe, W.G.
	Title	Thermodynamic equilibrium theory revealing increased hysteresis in ferroelectric field-effect transistors with free charge accumulation			Type	A1 Journal article
	Year	2021	Publication	Communications Physics	Abbreviated Journal
	Volume	4	Issue	1	Pages	86
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	At the core of the theoretical framework of the ferroelectric field-effect transistor (FeFET) is the thermodynamic principle that one can determine the equilibrium behavior of ferroelectric (FERRO) systems using the appropriate thermodynamic potential. In literature, it is often implicitly assumed, without formal justification, that the Gibbs free energy is the appropriate potential and that the impact of free charge accumulation can be neglected. In this Article, we first formally demonstrate that the Grand Potential is the appropriate thermodynamic potential to analyze the equilibrium behavior of perfectly coherent and uniform FERRO-systems. We demonstrate that the Grand Potential only reduces to the Gibbs free energy for perfectly non-conductive FERRO-systems. Consequently, the Grand Potential is always required for free charge-conducting FERRO-systems. We demonstrate that free charge accumulation at the FERRO interface increases the hysteretic device characteristics. Lastly, a theoretical best-case upper limit for the interface defect density D-FI is identified. The ferroelectric field-effect transistor, which has attracted much attention for application as both a highly energy-efficient logic device and a non-volatile memory device, has often been studied within the framework of equilibrium thermodynamics. Here, the authors theoretically demonstrate the importance of utilizing the correct thermodynamic potential and investigate the impact of free charge accumulation on the equilibrium performance of ferroelectric-based systems.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000645913400001	Publication Date	2021-04-30
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2399-3650	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor		Times cited		Open Access	OpenAccess
	Notes				Approved	Most recent IF: NA
	Call Number	UA @ admin @ c:irua:179005			Serial	7031
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