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	Author	Vandenberghe, W.; Sorée, B.; Magnus, W.; Groeseneken, G.
	Title	Zener tunneling in semiconductors under nonuniform electric fields			Type	A1 Journal article
	Year	2010	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	107	Issue	5	Pages	054520,1-054520,7
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Recently, a renewed interest in Zener tunneling has arisen because of its increasing impact on semiconductor device performance at nanometer dimensions. In this paper we evaluate the tunnel probability under the action of a nonuniform electric field using a two-band model and arrive at significant deviations from the commonly used Kanes model, valid for weak uniform fields only. A threshold on the junction bias where Kanes model for Zener tunneling breaks down is determined. Comparison with Kanes model particularly shows that our calculation yields a higher tunnel probability for intermediate electric fields and a lower tunnel probability for high electric fields. When performing a current calculation comparing to the WKB approximation for the case of an abrupt p-n junction significant differences concerning the shape of the I-V curve are demonstrated.
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000275657500136	Publication Date	2010-03-11
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-8979;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.068	Times cited	22	Open Access
	Notes	; William Vandenberghe gratefully acknowledges the support of a Ph. D. stipend from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen). These authors acknowledge the support from IMEC's Industrial Affiliation Program and the authors would like to thank Anne Verhulst for useful comments. ;			Approved	Most recent IF: 2.068; 2010 IF: 2.079
	Call Number	UA @ lucian @ c:irua:82450			Serial	3929
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	Author	Verreck, D.; Verhulst, A.S.; Van de Put, M.; Sorée, B.; Magnus, W.; Mocuta, A.; Collaert, N.; Thean, A.; Groeseneken, G.
	Title	Full-zone spectral envelope function formalism for the optimization of line and point tunnel field-effect transistors			Type	A1 Journal article
	Year	2015	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	118	Issue	118	Pages	134502
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Efficient quantum mechanical simulation of tunnel field-effect transistors (TFETs) is indispensable to allow for an optimal configuration identification. We therefore present a full-zone 15-band quantum mechanical solver based on the envelope function formalism and employing a spectral method to reduce computational complexity and handle spurious solutions. We demonstrate the versatility of the solver by simulating a 40 nm wide In0.53Ga0.47As lineTFET and comparing it to p-n-i-n configurations with various pocket and body thicknesses. We find that the lineTFET performance is not degraded compared to semi-classical simulations. Furthermore, we show that a suitably optimized p-n-i-n TFET can obtain similar performance to the lineTFET. (C) 2015 AIP Publishing LLC.
	Address
	Corporate Author				Thesis
	Publisher	American Institute of Physics	Place of Publication	New York, N.Y.	Editor
	Language		Wos	000362668400025	Publication Date	2015-10-01
	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	9	Open Access
	Notes	; D. Verreck acknowledges the support of a Ph.D. stipend from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen). This work was supported by imec's Industrial Affiliation Program. ;			Approved	Most recent IF: 2.068; 2015 IF: 2.183
	Call Number	UA @ lucian @ c:irua:128765			Serial	4183
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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
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	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	Mohammed, M.; Verhulst, A.S.; Verreck, D.; Van de Put, M.L.; Magnus, W.; Sorée, B.; Groeseneken, G.
	Title	Phonon-assisted tunneling in direct-bandgap semiconductors			Type	A1 Journal article
	Year	2019	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	125	Issue	1	Pages	015701
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	In tunnel field-effect transistors, trap-assisted tunneling (TAT) is one of the probable causes for degraded subthreshold swing. The accurate quantum-mechanical (QM) assessment of TAT currents also requires a QM treatment of phonon-assisted tunneling (PAT) currents. Therefore, we present a multi-band PAT current formalism within the framework of the quantum transmitting boundary method. An envelope function approximation is used to construct the electron-phonon coupling terms corresponding to local Frohlich-based phonon-assisted inter-band tunneling in direct-bandgap III-V semiconductors. The PAT current density is studied in up to 100 nm long and 20 nm wide p-n diodes with the 2- and 15-band material description of our formalism. We observe an inefficient electron-phonon coupling across the tunneling junction. We further demonstrate the dependence of PAT currents on the device length, for our non-self-consistent formalism which neglects changes in the electron distribution function caused by the electron-phonon coupling. Finally, we discuss the differences in doping dependence between direct band-to-band tunneling and PAT current. Published under license by AIP Publishing.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000455350200021	Publication Date	2019-01-02
	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	2	Open Access
	Notes	; This work was supported by Imec's Industrial Affiliation Program. ;			Approved	Most recent IF: 2.068
	Call Number	UA @ admin @ c:irua:156735			Serial	5224
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	Author	Verreck, D.; Verhulst, A.S.; Van de Put, M.L.; Sorée, B.; Magnus, W.; Collaert, N.; Mocuta, A.; Groeseneken, G.
	Title	Self-consistent procedure including envelope function normalization for full-zone Schrodinger-Poisson problems with transmitting boundary conditions			Type	A1 Journal article
	Year	2018	Publication	Journal of applied physics	Abbreviated Journal	J Appl Phys
	Volume	124	Issue	20	Pages	204501
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	In the quantum mechanical simulation of exploratory semiconductor devices, continuum methods based on a k.p/envelope function model have the potential to significantly reduce the computational burden compared to prevalent atomistic methods. However, full-zone k.p/envelope function simulation approaches are scarce and existing implementations are not self-consistent with the calculation of the electrostatic potential due to the lack of a stable procedure and a proper normalization of the multi-band envelope functions. Here, we therefore present a self-consistent procedure based on a full-zone spectral k.p/envelope function band structure model. First, we develop a proper normalization for the multi-band envelope functions in the presence of transmitting boundary conditions. This enables the calculation of the free carrier densities. Next, we construct a procedure to obtain self-consistency of the carrier densities with the electrostatic potential. This procedure is stabilized with an adaptive scheme that relies on the solution of Poisson's equation in the Gummel form, combined with successive underrelaxation. Finally, we apply our procedure to homostructure In0.53Ga0.47As tunnel field-effect transistors (TFETs) and staggered heterostructure GaAs0.5Sb0.5/In0.53Ga0.47As TFETs and show the importance of self-consistency on the device predictions for scaled dimensions. Published by AIP Publishing.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000451743900015	Publication Date	2018-11-30
	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	1	Open Access
	Notes	; This work was supported by imec's Industrial Affiliation Program. ;			Approved	Most recent IF: 2.068
	Call Number	UA @ admin @ c:irua:156291			Serial	5228
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	Author	Sorée, B.; Magnus, W.; Pourtois, G.
	Title	Analytical and self-consistent quantum mechanical model for a surrounding gate MOS nanowire operated in JFET mode			Type	A1 Journal article
	Year	2008	Publication	Journal of computational electronics	Abbreviated Journal	J Comput Electron
	Volume	7	Issue	3	Pages	380-383
	Keywords	A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	We derive an analytical model for the electrostatics and the drive current in a silicon nanowire operating in JFET mode. We show that there exists a range of nanowire radii and doping densities for which the nanowire JFET satisfies reasonable device characteristics. For thin nanowires we have developed a self-consistent quantum mechanical model to obtain the electronic structure.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	S.l.	Editor
	Language		Wos	000208473800067	Publication Date	2008-02-20
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1569-8025;1572-8137;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	1.526	Times cited	70	Open Access
	Notes				Approved	Most recent IF: 1.526; 2008 IF: NA
	Call Number	UA @ lucian @ c:irua:89504			Serial	107
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	Author	Slachmuylders, A.; Partoens, B.; Magnus, W.; Peeters, F.M.
	Title	The effect of dielectric mismatch on excitons and trions in cylindrical semiconductor nanowires			Type	A1 Journal article
	Year	2008	Publication	Journal of computational electronics	Abbreviated Journal	J Comput Electron
	Volume		Issue		Pages
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	S.l.	Editor
	Language		Wos	000208473800066	Publication Date	2008-02-19
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1569-8025;1572-8137;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	1.526	Times cited	2	Open Access
	Notes				Approved	Most recent IF: 1.526; 2008 IF: NA
	Call Number	UA @ lucian @ c:irua:69620			Serial	808
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	Author	Pourghaderi, M.A.; Magnus, W.; Sorée, B.; de Meyer, K.; Meuris, M.; Heyns, M.
	Title	General 2D Schrödinger-Poisson solver with open boundary conditions for nano-scale CMOS transistors			Type	A1 Journal article
	Year	2008	Publication	Journal of computational electronics	Abbreviated Journal	J Comput Electron
	Volume	7	Issue	4	Pages	475-484
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Employing the quantum transmitting boundary (QTB) method, we have developed a two-dimensional Schrödinger-Poisson solver in order to investigate quantum transport in nano-scale CMOS transistors subjected to open boundary conditions. In this paper we briefly describe the building blocks of the solver that was originally written to model silicon devices. Next, we explain how to extend the code to semiconducting materials such as germanium, having conduction bands with energy ellipsoids that are neither parallel nor perpendicular to the channel interfaces or even to each other. The latter introduces mixed derivatives in the 2D effective mass equation, thereby heavily complicating the implementation of open boundary conditions. We present a generalized quantum transmitting boundary method that mainly leans on the completeness of the eigenstates of the effective mass equation. Finally, we propose a new algorithm to calculate the chemical potentials of the source and drain reservoirs, taking into account their mutual interaction at high drain voltages. As an illustration, we present the potential and carrier density profiles obtained for a (111) Ge NMOS transistor as well as the ballistic current characteristics.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	S.l.	Editor
	Language		Wos	000209032500002	Publication Date	2008-09-02
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1569-8025;1572-8137;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	1.526	Times cited	3	Open Access
	Notes				Approved	Most recent IF: 1.526; 2008 IF: NA
	Call Number	UA @ lucian @ c:irua:89505			Serial	1322
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	Author	Magnus, W.; Brosens, F.; Sorée, B.
	Title	Modeling drive currents and leakage currents : a dynamic approach			Type	A1 Journal article
	Year	2009	Publication	Journal of computational electronics	Abbreviated Journal	J Comput Electron
	Volume	8	Issue	3/4	Pages	307-323
	Keywords	A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
	Abstract	The dynamics of electrons and holes propagating through the nano-scaled channels of modern semiconductor devices can be seen as a widespread manifestation of non-equilibrium statistical physics and its ruling principles. In this respect both the devices that are pushing conventional CMOS technology towards the final frontiers of Moores law and the upcoming set of alternative, novel nanostructures grounded on entirely new concepts and working principles, provide an almost unlimited playground for assessing physical models and numerical techniques emerging from classical and quantum mechanical non-equilibrium theory. In this paper we revisit the Boltzmann as well as the WignerBoltzmann equation which offers a valuable platform to study transport of charge carriers taking part in drive currents. We focus on a numerical procedure that regained attention recently as an alternative tool to solve the time-dependent Boltzmann equation for inhomogeneous systems, such as the channel regions of field-effect transistors, and we discuss its extension to the WignerBoltzmann equation. Furthermore, we pay attention to the calculation of tunneling leakage currents. The latter typically occurs in nano-scaled transistors when part of the carrier distribution sustaining the drive current is found to tunnel into the gate due the presence of an ultra-thin insulating barrier separating the gate from the channel region. In particular, we discuss the paradox related to the very existence of leakage currents established by electrons occupying quasi-bound states, while the (real) wave functions of the latter cannot carry net currents. Finally, we describe a simple model to resolve the paradox as well as to estimate gate currents provided the local carrier generation rates largely exceed the tunneling rates.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	S.l.	Editor
	Language		Wos	000208236100009	Publication Date	2009-09-28
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1569-8025;1572-8137;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	1.526	Times cited	4	Open Access
	Notes				Approved	Most recent IF: 1.526; 2009 IF: NA
	Call Number	UA @ lucian @ c:irua:89503			Serial	2110
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	Author	Sorée, B.; Magnus, W.
	Title	Quantized conductance without reservoirs : method of the nonequilibrium statistical operator			Type	A1 Journal article
	Year	2007	Publication	Journal of computational electronics	Abbreviated Journal	J Comput Electron
	Volume	6	Issue	1/3	Pages	255-258
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	We introduce a generalized non-equilibrium statistical operator (NSO) to study a current-carrying system. The NSO is used to derive a set of quantum kinetic equations based on quantum mechanical balance equations. The quantum kinetic equations are solved self-consistently together with Poissons equation to solve a general transport problem. We show that these kinetic equations can be used to rederive the Landauer formula for the conductance of a quantum point contact, without any reference to reservoirs at different chemical potentials. Instead, energy dissipation is taken into account explicitly through the electron-phonon interaction. We find that both elastic and inelastic scattering are necessary to obtain the Landauer conductance.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	S.l.	Editor
	Language		Wos	000208473600062	Publication Date	2007-01-17
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1569-8025;1572-8137;	ISBN		Additional Links	UA library record; WoS full record
	Impact Factor	1.526	Times cited		Open Access
	Notes				Approved	Most recent IF: 1.526; 2007 IF: NA
	Call Number	UA @ lucian @ c:irua:89506			Serial	2769
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	Author	Van de Put, M.L.; Sorée, B.; Magnus, W.
	Title	Efficient solution of the Wigner-Liouville equation using a spectral decomposition of the force field			Type	A1 Journal article
	Year	2017	Publication	Journal of computational physics	Abbreviated Journal	J Comput Phys
	Volume	350	Issue		Pages	314-325
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	The Wigner-Liouville equation is reformulated using a spectral decomposition of the classical force field instead of the potential energy. The latter is shown to simplify the Wigner-Liouville kernel both conceptually and numerically as the spectral force Wigner-Liouville equation avoids the numerical evaluation of the highly oscillatory Wigner kernel which is nonlocal in both position and momentum. The quantum mechanical evolution is instead governed by a term local in space and non-local in momentum, where the non locality in momentum has only a limited range. An interpretation of the time evolution in terms of two processes is presented; a classical evolution under the influence of the averaged driving field, and a probability-preserving quantum-mechanical generation and annihilation term. Using the inherent stability and reduced complexity, a direct deterministic numerical implementation using Chebyshev and Fourier pseudo-spectral methods is detailed. For the purpose of illustration, we present results for the time evolution of a one-dimensional resonant tunneling diode driven out of equilibrium. (C) 2017 Elsevier Inc. All rights reserved.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	New York	Editor
	Language		Wos	000413379000016	Publication Date	2017-09-02
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-9991	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.744	Times cited	5	Open Access
	Notes	; ;			Approved	Most recent IF: 2.744
	Call Number	UA @ lucian @ c:irua:146630			Serial	4780
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	Author	Slachmuylders, A.F.; Partoens, B.; Magnus, W.; Peeters, F.M.
	Title	Exciton states in cylindrical nanowires			Type	A1 Journal article
	Year	2006	Publication	Journal of physics : condensed matter	Abbreviated Journal	J Phys-Condens Mat
	Volume	18	Issue	16	Pages	3951-3966
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	London	Editor
	Language		Wos	000237749000013	Publication Date	2006-04-04
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0953-8984;1361-648X;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.649	Times cited	27	Open Access
	Notes				Approved	Most recent IF: 2.649; 2006 IF: 2.038
	Call Number	UA @ lucian @ c:irua:59473			Serial	1118
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	Author	Moors, K.; Sorée, B.; Magnus, W.
	Title	Validity criteria for Fermi's golden rule scattering rates applied to metallic nanowires			Type	A1 Journal article
	Year	2016	Publication	Journal of physics : condensed matter	Abbreviated Journal	J Phys-Condens Mat
	Volume	28	Issue	28	Pages	365302
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Fermi's golden rule underpins the investigation of mobile carriers propagating through various solids, being a standard tool to calculate their scattering rates. As such, it provides a perturbative estimate under the implicit assumption that the effect of the interaction Hamiltonian which causes the scattering events is sufficiently small. To check the validity of this assumption, we present a general framework to derive simple validity criteria in order to assess whether the scattering rates can be trusted for the system under consideration, given its statistical properties such as average size, electron density, impurity density et cetera. We derive concrete validity criteria for metallic nanowires with conduction electrons populating a single parabolic band subjected to different elastic scattering mechanisms: impurities, grain boundaries and surface roughness.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	London	Editor
	Language		Wos	000380754400013	Publication Date	2016-07-12
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0953-8984	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.649	Times cited	2	Open Access
	Notes	; ;			Approved	Most recent IF: 2.649
	Call Number	UA @ lucian @ c:irua:135011			Serial	4274
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	Author	Vanherck, J.; Sorée, B.; Magnus, W.
	Title	Anisotropic bulk and planar Heisenberg ferromagnets in uniform, arbitrarily oriented magnetic fields			Type	A1 Journal article
	Year	2018	Publication	Journal of physics : condensed matter	Abbreviated Journal	J Phys-Condens Mat
	Volume	30	Issue	27	Pages	275801
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Today, further downscaling of mobile electronic devices poses serious problems, such as energy consumption and local heat dissipation. In this context, spin wave majority gates made of very thin ferromagnetic films may offer a viable alternative. However, similar downscaling of magnetic thin films eventually enforces the latter to operate as quasi-2D magnets, the magnetic properties of which are not yet fully understood, especially those related to anisotropies and external magnetic fields in arbitrary directions. To this end, we have investigated the behaviour of an easy-plane and easy-axis anisotropic ferromagnet-both in two and three dimensions-subjected to a uniform magnetic field, applied along an arbitrary direction. In this paper, a spin-1/2 Heisenberg Hamiltonian with anisotropic exchange interactions is solved using double-time temperature-dependent Green's functions and the Tyablikov decoupling approximation. We determine various magnetic properties such as the Curie temperature and the magnetization as a function of temperature and the applied magnetic field, discussing the impact of the system's dimensionality and the type of anisotropy. The magnetic reorientation transition taking place in anisotropic Heisenberg ferromagnets is studied in detail. Importantly, spontaneous magnetization is found to be absent for easy-plane 2D spin systems with short range interactions.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	London	Editor
	Language		Wos	000434980600001	Publication Date	2018-05-21
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0953-8984	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.649	Times cited		Open Access
	Notes	; ;			Approved	Most recent IF: 2.649
	Call Number	UA @ lucian @ c:irua:151945UA @ admin @ c:irua:151945			Serial	5012
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	Author	Li, B.; Magnus, W.; Peeters, F.M.
	Title	Tunable exciton Aharonov-Bohm effect in a quantum ring			Type	A1 Journal article
	Year	2010	Publication	Journal of physics : conference series T2 – Proceedings of the 11th International Conference on Optics of Excitons in Confined Systems, September 7-11, 2009, Spain / Vina, L. [edit.]; et al. [edit.]	Abbreviated Journal
	Volume	210	Issue	1	Pages	012030,1-01203,4
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	We studied the optical Aharonov-Bohm effect for an exciton in a semiconductor quantum ring. A perpendicular electric field applied to a quantum ring with large height, is able to tune the exciton ground state energy such that it exhibits a weak observable Aharonov-Bohm oscillations. This Aharonov-Bohm effect is tunable in strength and period.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Bristol	Editor
	Language		Wos	000289715800242	Publication Date	2010-03-03
	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	3	Open Access
	Notes	; ;			Approved	Most recent IF: NA
	Call Number	UA @ lucian @ c:irua:89950			Serial	3741
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	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	Kenawy, A.; Magnus, W.; Sorée, B.
	Title	Flux quantization and Aharonov-Bohm effect in superconducting rings			Type	A1 Journal article
	Year	2018	Publication	Journal of superconductivity and novel magnetism	Abbreviated Journal	J Supercond Nov Magn
	Volume	31	Issue	5	Pages	1351-1357
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Superconductivity is a macroscopic coherent state exhibiting various quantum phenomena such as magnetic flux quantization. When a superconducting ring is placed in a magnetic field, a current flows to expel the field from the ring and to ensure that the enclosed flux is an integer multiple of h/(2\|e\|). Although the quantization of magnetic flux in ring structures is extensively studied in literature, the applied magnetic field is typically assumed to be homogeneous, implicitly implying an interplay between field expulsion and flux quantization. Here, we propose to decouple these two effects by employing an Aharonov-Bohm-like structure where the superconducting ring is threaded by a magnetic core (to which the applied field is confined). Although the magnetic field vanishes inside the ring, the formation of vortices takes place, corresponding to a change in the flux state of the ring. The time evolution of the density of superconducting electrons is studied using the time-dependent Ginzburg-Landau equations.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	New York, N.Y.	Editor
	Language		Wos	000429354100010	Publication Date	2017-10-09
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1557-1939	ISBN		Additional Links	UA library record; WoS full record
	Impact Factor	1.18	Times cited		Open Access
	Notes	; ;			Approved	Most recent IF: 1.18
	Call Number	UA @ lucian @ c:irua:150742UA @ admin @ c:irua:150742			Serial	4969
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	Author	Lujan, G.S.; Magnus, W.; Sorée, B.; Ragnarsson, L.A.; Trojman, L.; Kubicek, S.; De Gendt, S.; Heyns, A.; De Meyer, K.
	Title	Barrier permeation effects on the inversion layer subband structure and its applications to the electron mobility			Type	A1 Journal article
	Year	2005	Publication	Microelectronic engineering	Abbreviated Journal	Microelectron Eng
	Volume	80	Issue		Pages	82-85
	Keywords	A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
	Abstract	The electron wave functions in the inversion layer are analyzed in the case where the dielectric barriers are not infinite. This forces the electron concentration closer to the interface silicon/oxide and reduces the subband energy. This treatment of the inversion layer is extended to the calculation of the electron mobility degradation due to remote Coulomb scattering on a high-k dielectric stacked transistor. The subband energy reduction leads to a decrease of the scattering charge needed to explain the experimental results. This model can also fit better the experimental data when compared with the case where no barrier permeation is considered.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000231517000021	Publication Date	2005-06-05
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0167-9317;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	1.806	Times cited	1	Open Access
	Notes				Approved	Most recent IF: 1.806; 2005 IF: 1.347
	Call Number	UA @ lucian @ c:irua:102729			Serial	222
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	Author	Pourtois, G.; Lauwers, A.; Kittl, J.; Pantisano, L.; Sorée, B.; De Gendt, S.; Magnus, W.; Heyns, A.; Maex, K.
	Title	First-principle calculations on gate/dielectric interfaces : on the origin of work function shifts			Type	A1 Journal article
	Year	2005	Publication	Microelectronic engineering	Abbreviated Journal	Microelectron Eng
	Volume	80	Issue		Pages	272-279
	Keywords	A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	The impact of interfacial chemistry occurring at dielectric/gate interface of P-MOS and N-MOS devices is reviewed through a quick literature survey. A specific emphasis is put on the way the bond polarization that occurs between a dielectric and a metal substrate impacts on the gate work function. First-principle simulations are then used to study the work function changes induced by dopant aggregation in nickel monosilicide metal gates. It is shown that the changes are a natural consequence of the variation of the interface polarization.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000231517000062	Publication Date	2005-06-05
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0167-9317;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	1.806	Times cited	31	Open Access
	Notes				Approved	Most recent IF: 1.806; 2005 IF: 1.347
	Call Number	UA @ lucian @ c:irua:95095			Serial	1199
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	Author	Moors, K.; Sorée, B.; Magnus, W.
	Title	Resistivity scaling in metallic thin films and nanowires due to grain boundary and surface roughness scattering			Type	A1 Journal article
	Year	2017	Publication	Microelectronic engineering	Abbreviated Journal	Microelectron Eng
	Volume	167	Issue	167	Pages	37-41
	Keywords	A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
	Abstract	A modeling approach, based on an analytical solution of the semiclassical multi-subband Boltzmann transport equation, is presented to study resistivity scaling in metallic thin films and nanowires due to grain boundary and surface roughness scattering. While taking into account the detailed statistical properties of grains, roughness and barrier material as well as the metallic band structure and quantum mechanical aspects of scattering and confinement, the model does not rely on phenomenological fitting parameters. (C) 2016 Elsevier B.V. All rights reserved.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000390746000008	Publication Date	2016-10-20
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0167-9317	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	1.806	Times cited	6	Open Access
	Notes	; ;			Approved	Most recent IF: 1.806
	Call Number	UA @ lucian @ c:irua:140354			Serial	4460
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	Author	Li, B.; Partoens, B.; Peeters, F.M.; Magnus, W.
	Title	Dielectric mismatch effect on coupled impurity states in a freestanding nanowire			Type	A1 Journal article
	Year	2009	Publication	Microelectronics journal	Abbreviated Journal	Microelectron J
	Volume	40	Issue	3	Pages	446-448
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	We studied the coupled impurity states in a freestanding semiconductor nanowire (NW), within the effective mass approximation and including the effect of the dielectric mismatch, by using finite element method. Bonding and anti-bonding states are found and their energies converge with increasing distance di between the two impurities. The dependence of the binding energy on the wire radius R and the distance di between the two impurities is investigated, and we compare it with the result of a freestanding NW that contains a single impurity.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Luton	Editor
	Language		Wos	000264694700017	Publication Date	2008-07-30
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0026-2692;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	1.163	Times cited	4	Open Access
	Notes				Approved	Most recent IF: 1.163; 2009 IF: 0.778
	Call Number	UA @ lucian @ c:irua:76410			Serial	690
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	Author	Slachmuylders, A.F.; Partoens, B.; Magnus, W.; Peeters, F.M.
	Title	Neutral shallow donors near a metallic interface			Type	A1 Journal article
	Year	2009	Publication	Microelectronics journal	Abbreviated Journal	Microelectron J
	Volume	40	Issue	4/5	Pages	753-755
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	The effect of a metallic gate on the bound states of a shallow donor located near the gate is studied. We calculate the energy spectrum as a function of the distance between the metallic gate and the donor and find an anti-crossing behavior in the energy levels for certain distances. We show how a transverse electric field can tune the average position of the electron with respect to the metallic gate and the impurity.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Luton	Editor
	Language		Wos	000265870200024	Publication Date	2009-02-04
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0026-2692;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	1.163	Times cited	1	Open Access
	Notes				Approved	Most recent IF: 1.163; 2009 IF: 0.778
	Call Number	UA @ lucian @ c:irua:77029			Serial	2296
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	Author	Moors, K.; Soree, B.; Tokei, Z.; Magnus, W.
	Title	Electron relaxation times and resistivity in metallic nanowires due to tilted grain boundary planes			Type	P1 Proceeding
	Year	2015	Publication	On Ultimate Integration On Silicon (eurosoi-ulis)	Abbreviated Journal
	Volume		Issue		Pages	201-204
	Keywords	P1 Proceeding; Condensed Matter Theory (CMT)
	Abstract	We calculate the resistivity contribution of tilted grain boundaries with varying parameters in sub-10nm diameter metallic nanowires. The results have been obtained with the Boltzmann transport equation and Fermi's golden rule, retrieving correct state-dependent relaxation times. The standard approximation schemes for the relaxation times are shown to fail when grain boundary tilt is considered. Grain boundaries tilted under the same angle or randomly tilted induce a resistivity decrease.
	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	978-1-4799-6911-1	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor		Times cited		Open Access
	Notes				Approved	Most recent IF: NA
	Call Number	UA @ lucian @ c:irua:144776			Serial	4651
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	Author	Brosens, F.; Magnus, W.
	Title	Carrier transport in nanodevices: revisiting the Boltzmann and Wigner distribution functions			Type	A1 Journal article
	Year	2009	Publication	Physica status solidi: B: basic research	Abbreviated Journal	Phys Status Solidi B
	Volume	246	Issue	7	Pages	1656-1661
	Keywords	A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
	Abstract	In principle, transport of charged carriers in nanometer sized solid-state devices can be fully characterized once the non-equilibrium distribution function describing the carrier ensemble is known. In this light, we have revisited the Boltzmann and the Wigner distribution functions and the framework in which they emerge from the classical respectively quantum mechanical Liouville equation. We have assessed the method of the characteristic curves as a potential workhorse to solve the time dependent Boltzmann equation for carriers propagating through spatially non-uniform systems, such as nanodevices. In order to validate the proposed solution strategy, we numerically solve the Boltzmann equation for a one-dimensional conductor mimicking the basic features of a biased low-dimensional transistor operating in the on-state. Finally, we propose a computational scheme capable of extending the benefits of the above mentioned solution strategy when it comes to solve the Wigner-Liouville equation.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Berlin	Editor
	Language		Wos	000268659100033	Publication Date	2009-04-22
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0370-1972;1521-3951;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	1.674	Times cited	8	Open Access
	Notes				Approved	Most recent IF: 1.674; 2009 IF: 1.150
	Call Number	UA @ lucian @ c:irua:77953			Serial	284
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	Author	van Rossum, M.; Schoenmaker, W.; Magnus, W.; de Meyer, K.; Croitoru, M.D.; Gladilin, V.N.; Fomin, V.M.; Devreese, J.T.
	Title	Moore's law: new playground for quantum physics			Type	A1 Journal article
	Year	2003	Publication	Physica status solidi: B: basic research	Abbreviated Journal	Phys Status Solidi B
	Volume	237	Issue		Pages	426-432
	Keywords	A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT)
	Abstract
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Berlin	Editor
	Language		Wos	000182801800041	Publication Date	2003-04-24
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0370-1972;1521-3951;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	1.674	Times cited	2	Open Access
	Notes				Approved	Most recent IF: 1.674; 2003 IF: 0.987
	Call Number	UA @ lucian @ c:irua:44284			Serial	2202
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	Author	Slachmuylders, A.F.; Partoens, B.; Magnus, W.; Peeters, F.M.
	Title	Excitons and trions in cylindrical nanowires with dielectric mismatch			Type	A1 Journal article
	Year	2008	Publication	Physica status solidi: C: conferences and critical reviews	Abbreviated Journal
	Volume	5	Issue	7	Pages	2416-2419
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Berlin	Editor
	Language		Wos	000257507200009	Publication Date	2008-02-20
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1862-6351;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor		Times cited	3	Open Access
	Notes				Approved	Most recent IF: NA
	Call Number	UA @ lucian @ c:irua:69641			Serial	1127
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	Author	Slachmuylders, A.F.; Partoens, B.; Magnus, W.; Peeters, F.M.
	Title	The effect of the dielectric mismatch on excitons and trions in freestanding nanowires			Type	A1 Journal article
	Year	2008	Publication	Physica. E: Low-dimensional systems and nanostructures	Abbreviated Journal	Physica E
	Volume	40	Issue	6	Pages	2166-2168
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000255717400122	Publication Date	2007-12-05
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1386-9477;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.221	Times cited	3	Open Access
	Notes				Approved	Most recent IF: 2.221; 2008 IF: 1.230
	Call Number	UA @ lucian @ c:irua:69155			Serial	846
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	Author	Sels, D.; Brosens, F.; Magnus, W.
	Title	Classical trajectories : a powerful tool for solving tunneling problems			Type	A1 Journal article
	Year	2012	Publication	Physica: A : theoretical and statistical physics	Abbreviated Journal	Physica A
	Volume	391	Issue	1/2	Pages	78-81
	Keywords	A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT)
	Abstract	In the realm of Ehrenfests theorem, classical trajectories obeying Newtons laws have been proven useful to construct explicit solutions to the time-dependent WignerLiouville equation. Whereas previous works have particularly focused on the initial distribution function as a vehicle found to carry the signatures of quantum statistics into the time-dependent solution, the present paper shows that the LagrangeCharpit method based on classical trajectories can be successfully invoked as well to tackle quantum mechanical features with no classical counterpart, such as tunneling.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000297230700010	Publication Date	2011-08-25
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0378-4371;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.243	Times cited	7	Open Access
	Notes	; ;			Approved	Most recent IF: 2.243; 2012 IF: 1.676
	Call Number	UA @ lucian @ c:irua:92359			Serial	370
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	Author	Magnus, W.; Nelissen, K.
	Title	Quantum diffusion: A simple, exactly solvable model			Type	A1 Journal article
	Year	2015	Publication	Physica: A : theoretical and statistical physics	Abbreviated Journal	Physica A
	Volume	417	Issue	417	Pages	96-101
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	We propose a simple quantum mechanical model describing the time dependent diffusion current between two fermion reservoirs that were initially disconnected and characterized by different densities or chemical potentials. The exact, analytical solution of the model yields the transient behavior of the coupled fermion systems evolving to a final steady state, whereas the long-time behavior is determined by a power law rather than by exponential decay. Similar results are obtained for the entropy production which is proportional to the diffusion current. (C) 2014 Elsevier B.V. All rights reserved.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000345721800011	Publication Date	2014-09-28
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0378-4371;	ISBN		Additional Links	UA library record; WoS full record
	Impact Factor	2.243	Times cited		Open Access
	Notes	; ;			Approved	Most recent IF: 2.243; 2015 IF: 1.732
	Call Number	c:irua:122170			Serial	2777
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