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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	Lauwens, J.; Kerkhofs, L.; Sala, A.; Sorée, B.
	Title	Superconductor-semiconductor hybrid capacitance with a nonlinear charge-voltage profile			Type	A1 Journal article
	Year	2024	Publication	Journal of physics: D: applied physics	Abbreviated Journal
	Volume	57	Issue	2	Pages	025301-25309
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Electronic devices that work in the quantum regime often employ hybrid nanostructures to bring about a nonlinear behaviour. The nonlinearity that these can provide has proven to be useful, in particular, for applications in quantum computation. Here we present a hybrid device that acts as a capacitor with a nonlinear charge-voltage relation. The device consists of a nanowire placed between the plates of a coplanar capacitor, with a co-parallel alignment. At low temperatures, due to the finite density of states on the nanowire, the charge distribution in the capacitor is uneven and energy-dependent, resulting in a charge-dependent effective capacitance. We study this system analytically and numerically, and show that the nonlinearity of the capacitance is significant enough to be utilized in circuit quantum electrodynamics. The resulting nonlinearity can be switched on, modulated, and switched off by an external potential, thus making this capacitive device highly versatile for uses in quantum computation.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	001082883200001	Publication Date	2023-09-29
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0022-3727	ISBN		Additional Links	UA library record; WoS full record
	Impact Factor		Times cited		Open Access
	Notes				Approved	no
	Call Number	UA @ admin @ c:irua:200300			Serial	9099
Permanent link to this record



	Author	Deylgat, E.; Chen, E.; Sorée, B.; Vandenberghe, W.G.
	Title	Quantum transport study of contact resistance of edge- and top-contacted two-dimensional materials			Type	P1 Proceeding
	Year	2023	Publication	International Conference on Simulation of Semiconductor Processes and Devices : [proceedings] T2 – International Conference on Simulation of Semiconductor Processes and, Devices (SISPAD), SEP 27-29, 2023, Kobe, Japan	Abbreviated Journal
	Volume		Issue		Pages	45-48
	Keywords	P1 Proceeding; Condensed Matter Theory (CMT)
	Abstract	We calculate the contact resistance for an edge- and top-contacted 2D semiconductor. The contact region consists of a metal contacting a monolayer of MoS2 which is otherwise surrounded by SiO2. We use the quantum transmitting boundary method to compute the contact resistance as a function of the 2D semiconductor doping concentration. An effective mass Hamiltonian is used to describe the properties of the various materials. The electrostatic potentials are obtained by solving the Poisson equation numerically. We incorporate the effects of the image-force barrier lowering on the Schottky barrier and examine the impact on the contact resistance. At low doping concentrations, the contact resistance of the top contact is lower compared to edge contact, while at high doping concentrations, the edge contact exhibits lower resistance.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	001117703800012	Publication Date	2023-11-20
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	978-4-86348-803-8	ISBN		Additional Links	UA library record; WoS full record
	Impact Factor		Times cited		Open Access
	Notes				Approved	no
	Call Number	UA @ admin @ c:irua:202839			Serial	9079
Permanent link to this record



	Author	Reyntjens, P.; Van de Put, M.; Vandenberghe, W.G.; Sorée, B.
	Title	Ultrascaled graphene-capped interconnects : a quantum mechanical study			Type	P1 Proceeding
	Year	2023	Publication	Proceedings of the IEEE ... International Interconnect Technology Conference T2 – IEEE International Interconnect Technology Conference (IITC) / IEEE, Materials for Advanced Metallization Conference (MAM), MAY 22-25, 2023, Dresden, Germany	Abbreviated Journal
	Volume		Issue		Pages	1-3
	Keywords	P1 Proceeding; Condensed Matter Theory (CMT)
	Abstract	In this theoretical study, we assess the impact of a graphene capping layer on the resistivity of defective, extremely scaled interconnects. We investigate the effect of graphene capping on the electronic transport in ultrascaled interconnects, in the presence of grain boundary defects in the metal layer. We compare the results obtained using our quantum mechanical model to a simple parallel-conductor model and find that the parallel-conductor model does not capture the effect of the graphene cap correctly. At 0.5 nm metal thickness, the parallel-conductor model underestimates the conductivity by 3.0% to 4.0% for single-sided and double sided graphene capping, respectively.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	001027381700006	Publication Date	2023-06-24
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	979-83-503-1097-9	ISBN		Additional Links	UA library record; WoS full record
	Impact Factor		Times cited		Open Access	Not_Open_Access
	Notes				Approved	Most recent IF: NA
	Call Number	UA @ admin @ c:irua:198343			Serial	8949
Permanent link to this record



	Author	Tiwari, S.; Van de Put, M.L.; Temst, K.; Vandenberghe, W.G.; Sorée, B.
	Title	Atomistic modeling of spin and electron dynamics in two-dimensional magnets switched by two-dimensional topological insulators			Type	A1 Journal article
	Year	2023	Publication	Physical review applied	Abbreviated Journal
	Volume	19	Issue	1	Pages	014040-14049
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	To design fast memory devices, we need material combinations that can facilitate fast read and write operations. We present a heterostructure comprising a two-dimensional (2D) magnet and a 2D topological insulator (TI) as a viable option for designing fast memory devices. We theoretically model the spin-charge dynamics between 2D magnets and 2D TIs. Using the adiabatic approximation, we combine the nonequi-librium Green's function method for spin-dependent electron transport and a time-quantified Monte Carlo method for simulating magnetization dynamics. We show that it is possible to switch a magnetic domain of a ferromagnet using the spin torque from spin-polarized edge states of a 2D TI. We show further that the switching of 2D magnets by TIs is strongly dependent on the interface exchange (Jint), and an opti-mal interface exchange, is required for efficient switching. Finally, we compare experimentally grown Cr compounds and show that Cr compounds with higher anisotropy (such as CrI3) result in a lower switching speed but a more stable magnetic order.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000920227500002	Publication Date	2023-01-12
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2331-7019	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	4.6	Times cited		Open Access	Not_Open_Access
	Notes				Approved	Most recent IF: 4.6; 2023 IF: 4.808
	Call Number	UA @ admin @ c:irua:194312			Serial	7283
Permanent link to this record



	Author	Deylgat, E.; Chen, E.; Fischetti, M.V.; Sorée, B.; Vandenberghe, W.G.
	Title	Image-force barrier lowering in top- and side-contacted two-dimensional materials			Type	A1 Journal article
	Year	2022	Publication	Solid state electronics	Abbreviated Journal	Solid State Electron
	Volume	198	Issue		Pages	108458-4
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	We compare the image-force barrier lowering (IFBL) and calculate the resulting contact resistance for four different metal-dielectric-two-dimensional (2D) material configurations. We analyze edge contacts in three different geometries (a homogeneous dielectric throughout, including the 2D layer; a homogeneous dielectric surrounding the 2D layer, both ungated and back gated) and also a top-contact assuming a homogeneous dielectric. The image potential energy of each configuration is determined and added to the Schottky energy barrier which is calculated assuming a textbook Schottky potential. For each configuration, the contact resistivity is calculated using the WKB approximation and the effective mass approximation using either SiO2 or HfO2 as the surrounding dielectric. We obtain the lowest contact resistance of 1 k Omega mu m by n-type doping an edge contacted transition metal-dichalcogenide (TMD) monolayer, sandwiched between SiO2 dielectric, with similar to 1012 cm-2 donor atoms. When this optimal configuration is used, the contact resistance is lowered by a factor of 50 compared to the situation when the IFBL is not considered.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000876289800003	Publication Date	2022-09-22
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0038-1101	ISBN		Additional Links	UA library record; WoS full record
	Impact Factor	1.7	Times cited		Open Access	Not_Open_Access
	Notes				Approved	Most recent IF: 1.7
	Call Number	UA @ admin @ c:irua:191556			Serial	7312
Permanent link to this record



	Author	Vanderveken, F.; Tyberkevych, V.; Talmelli, G.; Sorée, B.; Ciubotaru, F.; Adelmann, C.
	Title	Lumped circuit model for inductive antenna spin-wave transducers			Type	A1 Journal article
	Year	2022	Publication	Scientific reports	Abbreviated Journal	Sci Rep-Uk
	Volume	12	Issue	1	Pages	3796-13
	Keywords	A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
	Abstract	We derive a lumped circuit model for inductive antenna spin-wave transducers in the vicinity of a ferromagnetic medium. The model considers the antenna's Ohmic resistance, its inductance, as well as the additional inductance due to the excitation of ferromagnetic resonance or spin waves in the ferromagnetic medium. As an example, the additional inductance is discussed for a wire antenna on top of a ferromagnetic waveguide, a structure that is characteristic for many magnonic devices and experiments. The model is used to assess the scaling properties and the energy efficiency of inductive antennas. Issues related to scaling antenna transducers to the nanoscale and possible solutions are also addressed.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000826474600050	Publication Date	2022-03-08
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2045-2322	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	4.6	Times cited		Open Access	OpenAccess
	Notes				Approved	Most recent IF: 4.6
	Call Number	UA @ admin @ c:irua:190001			Serial	7180
Permanent link to this record



	Author	Sethu, K.K.V.; Ghosh, S.; Couet, S.; Swerts, J.; Sorée, B.; De Boeck, J.; Kar, G.S.; Garello, K.
	Title	Optimization of tungsten beta-phase window for spin-orbit-torque magnetic random-access memory			Type	A1 Journal article
	Year	2021	Publication	Physical Review Applied	Abbreviated Journal	Phys Rev Appl
	Volume	16	Issue	6	Pages	064009
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Switching induced by spin-orbit torque (SOT) is being vigorously explored, as it allows the control of magnetization using an in-plane current, which enables a three-terminal magnetic-tunnel-junction geometry with isolated read and write paths. This significantly improves the device endurance and the read stability, and allows reliable subnanosecond switching. Tungsten in the beta phase, beta-W, has the largest reported antidamping SOT charge-to-spin conversion ratio (theta(AD) approximate to -60%) for heavy metals. However, beta-W has a limitation when one is aiming for reliable technology integration: the beta phase is limited to a thickness of a few nanometers and enters the alpha phase above 4 nm in our samples when industry-relevant deposition tools are used. Here, we report our approach to extending the range of beta-W, while simultaneously improving the SOT efficiency by introducing N and O doping of W. Resistivity and XRD measurements confirm the extension of the beta phase from 4 nm to more than 10 nm, and transport characterization shows an effective SOT efficiency larger than -44.4% (reaching approximately -60% for the bulk contribution). In addition, we demonstrate the possibility of controlling and enhancing the perpendicular magnetic anisotropy of a storage layer (Co-Fe-B). Further, we integrate the optimized W(O, N) into SOT magnetic random-access memory (SOT-MRAM) devices and project that, for the same thickness of SOT material, the switching current decreases by 25% in optimized W(O, N) compared with our standard W. Our results open the path to using and further optimizing W for integration of SOT-MRAM technology.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000729005800002	Publication Date	2021-12-03
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2331-7019	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	4.808	Times cited		Open Access	Not_Open_Access
	Notes				Approved	Most recent IF: 4.808
	Call Number	UA @ admin @ c:irua:184832			Serial	7007
Permanent link to this record



	Author	Tiwari, S.; Van de Put, M.L.; Sorée, B.; Vandenberghe, W.G.
	Title	Ab initio modeling of few-layer dilute magnetic semiconductors			Type	P1 Proceeding
	Year	2021	Publication	International Conference on Simulation of Semiconductor Processes and Devices : [proceedings] T2 – International Conference on Simulation of Semiconductor Processes and, Devices (SISPAD), SEP 27-29, 2021, Dallas, TX	Abbreviated Journal
	Volume		Issue		Pages	141-145
	Keywords	P1 Proceeding; Engineering sciences. Technology; Condensed Matter Theory (CMT)
	Abstract	We present a computational model to model the magnetic structure of two-dimensional (2D) dilute-magnetic-semiconductors (DMS) both the monolayers and multilayers using first-principles density functional theory (DFT), as well as their magnetic phase transition as a function of temperature using Monte-Carlo simulations. Using our method, we model the magnetic structure of bulk, bilayer, and monolayer MoS2 substitutionally doped with Fe atoms. We find that the out-of-plane interaction in bilayer MoS2 is weakly ferromagnetic, whereas in bulk MoS2 it is strongly anti-ferromagnetic. Finally, we show that the magnetic order is more robust in bilayer Fe-doped MoS2 compared to the monolayer and results in a room-temperature FM at an atomic substitution of 14-16%.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000766985400034	Publication Date	2021-11-08
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	978-1-6654-0685-7	ISBN		Additional Links	UA library record; WoS full record
	Impact Factor		Times cited		Open Access	Not_Open_Access
	Notes				Approved	Most recent IF: NA
	Call Number	UA @ admin @ c:irua:187291			Serial	7401
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	Osca, J.; Sorée, B.
	Title	Torque field and skyrmion motion by spin transfer torque in a quasi-2D interface in presence of strong spin-orbit interaction			Type	A1 Journal article
	Year	2021	Publication	Journal Of Applied Physics	Abbreviated Journal	J Appl Phys
	Volume	130	Issue	13	Pages	133903
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	We investigate the torque field and skyrmion motion at an interface between a ferromagnet hosting a skyrmion and a material with a strong spin-orbit interaction. We analyze both semiconductor materials and topological insulators using a Hamiltonian model that includes a linear term. The spin torque-inducing current is considered to flow in the single band limit; therefore, a quantum model of current is used. Skyrmion motion due to spin transfer torque proves to be more difficult in the presence of a spin-orbit interaction in the case where only interface in-plane currents are present. However, edge effects in narrow nanowires can be used to drive the skyrmion motion and to exert a limited control on its motion direction. We also show the differences and similarities between torque fields due to electric current in the many and single band limits. Published under an exclusive license by AIP Publishing.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000755090400003	Publication Date	2021-10-07
	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		Open Access	Not_Open_Access
	Notes				Approved	Most recent IF: 2.068
	Call Number	UA @ admin @ c:irua:186452			Serial	7034
Permanent link to this record



	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
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	Osca, J.; Moors, K.; Sorée, B.; Serra, L.
	Title	Fabry-Perot interferometry with gate-tunable 3D topological insulator nanowires			Type	A1 Journal article
	Year	2021	Publication	Nanotechnology	Abbreviated Journal	Nanotechnology
	Volume	32	Issue	43	Pages	435002
	Keywords	A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
	Abstract	Three-dimensional topological insulator (3D TI) nanowires display remarkable magnetotransport properties that can be attributed to their spin-momentum-locked surface states such as quasiballistic transport and Aharonov-Bohm oscillations. Here, we focus on the transport properties of a 3D TI nanowire with a gated section that forms an electronic Fabry-Perot (FP) interferometer that can be tuned to act as a surface-state filter or energy barrier. By tuning the carrier density and length of the gated section of the wire, the interference pattern can be controlled and the nanowire can become fully transparent for certain topological surface-state input modes while completely filtering out others. We also consider the interplay of FP interference with an external magnetic field, with which Klein tunneling can be induced, and transverse asymmetry of the gated section, e.g. due to a top-gated structure, which displays an interesting analogy with Rashba nanowires. Due to its rich conductance phenomenology, we propose a 3D TI nanowire with gated section as an ideal setup for a detailed transport-based characterization of 3D TI nanowire surface states near the Dirac point, which could be useful towards realizing 3D TI nanowire-based topological superconductivity and Majorana bound states.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000682173800001	Publication Date	2021-07-20
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0957-4484	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.44	Times cited		Open Access	Not_Open_Access
	Notes				Approved	Most recent IF: 3.44
	Call Number	UA @ admin @ c:irua:180487			Serial	6990
Permanent link to this record



	Author	Raymenants, E.; Bultynck, O.; Wan, D.; Devolder, T.; Garello, K.; Souriau, L.; Thiam, A.; Tsvetanova, D.; Canvel, Y.; Nikonov, D.E.; Young, I.A.; Heyns, M.; Sorée, B.; Asselberghs, I.; Radu, I.; Couet, S.; Nguyen, V.D.
	Title	Nanoscale domain wall devices with magnetic tunnel junction read and write			Type	A1 Journal article
	Year	2021	Publication	Nature Electronics	Abbreviated Journal
	Volume	4	Issue	6	Pages	392-398
	Keywords	A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
	Abstract	The manipulation of fast domain wall motion in magnetic nanostructures could form the basis of novel magnetic memory and logic devices. However, current approaches for reading and writing domain walls require external magnetic fields, or are based on conventional magnetic tunnel junctions (MTJs) that are not compatible with high-speed domain wall motion. Here we report domain wall devices based on perpendicular MTJs that offer electrical read and write, and fast domain wall motion via spin-orbit torque. The devices have a hybrid free layer design that consists of platinum/cobalt (Pt/Co) or a synthetic antiferromagnet (Pt/Co/Ru/Co) into the free layer of conventional MTJs. We show that our devices can achieve good tunnelling magnetoresistance readout and efficient spin-transfer torque writing that is comparable to current magnetic random-access memory technology, as well as domain wall depinning efficiency that is similar to stand-alone materials. We also show that a domain wall conduit based on a synthetic antiferromagnet offers the potential for reliable domain wall motion and faster write speed compared with a device based on Pt/Co. Domain wall devices based on perpendicular magnetic tunnel junctions with a hybrid free layer design can offer electrical read and write, and fast domain wall motion driven via spin-orbit torque.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000665011500005	Publication Date	2021-06-23
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2520-1131	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor		Times cited		Open Access	OpenAccess
	Notes				Approved	Most recent IF: NA
	Call Number	UA @ admin @ c:irua:179673			Serial	7003
Permanent link to this record



	Author	Tiwari, S.; Van de Put, M.L.; Sorée, B.; Vandenberghe, W.G.
	Title	Magnetic order and critical temperature of substitutionally doped transition metal dichalcogenide monolayers			Type	A1 Journal article
	Year	2021	Publication	npj 2D Materials and Applications	Abbreviated Journal
	Volume	5	Issue	1	Pages	54
	Keywords	A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
	Abstract	Using first-principles calculations, we investigate the magnetic order in two-dimensional (2D) transition-metal-dichalcogenide (TMD) monolayers: MoS2, MoSe2, MoTe2, WSe2, and WS2 substitutionally doped with period four transition-metals (Ti, V, Cr, Mn, Fe, Co, Ni). We uncover five distinct magnetically ordered states among the 35 distinct TMD-dopant pairs: the non-magnetic (NM), the ferromagnetic with out-of-plane spin polarization (Z FM), the out-of-plane polarized clustered FMs (clustered Z FM), the in-plane polarized FMs (X-Y FM), and the anti-ferromagnetic (AFM) state. Ni and Ti dopants result in an NM state for all considered TMDs, while Cr dopants result in an anti-ferromagnetically ordered state for all the TMDs. Most remarkably, we find that Fe, Mn, Co, and V result in an FM ordered state for all the TMDs, except for MoTe2. Finally, we show that V-doped MoSe2 and WSe2, and Mn-doped MoS2, are the most suitable candidates for realizing a room-temperature FM at a 16-18% atomic substitution.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000650635200004	Publication Date	2021-05-14
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2397-7132	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:179063			Serial	7001
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	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
Permanent link to this record



	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	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	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	Ab-initio study of magnetically intercalated Tungsten diselenide			Type	P1 Proceeding
	Year	2020	Publication	International Conference on Simulation of Semiconductor Processes and Devices : [proceedings] T2 – International Conference on Simulation of Semiconductor Processes and, Devices (SISPAD), SEP 23-OCT 06, 2020	Abbreviated Journal
	Volume		Issue		Pages	97-100
	Keywords	P1 Proceeding; Condensed Matter Theory (CMT)
	Abstract	We theoretically investigate the effect of intercalation of third row transition metals (Co, Cr, Fe, Mn, Ti and V) in the layers of WSe2. Using density functional theory (DFT), we investigate the structural stability. We also compute the DFT energies of various magnetic spin configurations. Using these energies, we construct a Heisenberg Hamiltonian and perform a Monte Carlo study on each WSe2 + intercalant system to estimate the Curie or Neel temperature. We find ferromagnetic ground states for Ti and Cr intercalation, with Curie temperatures of 31K and 225K, respectively. In Fe-intercalated WSe2, we predict that antiferromagnetic ordering is present up to 564K. For V intercalation, we find that the system exhibits a double phase transition.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000636981000025	Publication Date	2020-11-02
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	978-4-86348-763-5	ISBN		Additional Links	UA library record; WoS full record
	Impact Factor		Times cited		Open Access
	Notes				Approved	Most recent IF: NA
	Call Number	UA @ admin @ c:irua:178345			Serial	7402
Permanent link to this record



	Author	Osca, J.; Sorée, B.
	Title	Skyrmion spin transfer torque due to current confined in a nanowire			Type	A1 Journal article
	Year	2020	Publication	Physical Review B	Abbreviated Journal	Phys Rev B
	Volume	102	Issue	12	Pages	125436
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	In this work we compute the torque field present in a ferromagnet in contact with a metallic nanowire when a skyrmion is present. If the nanowire is narrow enough, then the current is carried by a single conduction band. In this regime the classical torque model breaks down and we show that a skyrmion driven by spin transfer torque moves in a different direction than predicted by the classical model. However, the amount of charge current required to move a skyrmion with a certain velocity in the single-band regime is similar to a classical model of torque where it is implicitly assumed current transport by many conduction bands. The single-band regime is more efficient creating spin current from charge current because of the perfect polarization of the single band but is less efficient creating torque from spin current. Nevertheless, it is possible to take profit of the single-band regime to move skyrmions even with no net charge or spin current flowing between the device contacts. We have also been able to recover the classical limit considering an ensemble of only a few electronic states. In this limit we have discovered that electron diffusion needs to be considered even in ballistic nanowires due the effect of the skyrmion structure on the electron current.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000573775300004	Publication Date	2020-09-30
	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	; The authors thanks Llorenc Serra for useful discussion on the conduction electron quantum model. We also want to show gratitude to Dimitrios Andrikopoulos for sharing his knowledge about the available bibliography and to F. J. P. van Duijn for his comments on earlier versions of this manuscript. We acknowledge the Horizon 2020 project SKYTOP “Skyrmion-Topological Insulator and Weyl Semimetal Technology” (FETPROACT-2018-01, No. 824123). Finally, J.O. also acknowledges the postdoctoral fellowship provided by KU Leuven. ;			Approved	Most recent IF: 3.7; 2020 IF: 3.836
	Call Number	UA @ admin @ c:irua:172727			Serial	6604
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	Author	Kenawy, A.; Magnus, W.; Milošević, M.V.; Sorée, B.
	Title	Electronically tunable quantum phase slips in voltage-biased superconducting rings as a base for phase-slip flux qubits			Type	A1 Journal article
	Year	2020	Publication	Superconductor Science & Technology	Abbreviated Journal	Supercond Sci Tech
	Volume	33	Issue	12	Pages	125002
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Quantum phase slips represent a coherent mechanism to couple flux states of a superconducting loop. Since their first direct observation, there have been substantial developments in building charge-insensitive quantum phase-slip circuits. At the heart of these devices is a weak link, often a nanowire, interrupting a superconducting loop. Owing to the very small cross-sectional area of such a nanowire, quantum phase slip rates in the gigahertz range can be achieved. Instead, here we present the use of a bias voltage across a superconducting loop to electrostatically induce a weak link, thereby amplifying the rate of quantum phase slips without physically interrupting the loop. Our simulations reveal that the bias voltage modulates the free energy barrier between subsequent flux states in a very controllable fashion, providing a route towards a phase-slip flux qubit with a broadly tunable transition frequency.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000577207000001	Publication Date	2020-09-16
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0953-2048	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.6	Times cited	4	Open Access
	Notes	; ;			Approved	Most recent IF: 3.6; 2020 IF: 2.878
	Call Number	UA @ admin @ c:irua:172643			Serial	6503
Permanent link to this record



	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	Vanherck, J.; Bacaksiz, C.; Sorée, B.; Milošević, M.V.; Magnus, W.
	Title	2D ferromagnetism at finite temperatures under quantum scrutiny			Type	A1 Journal article
	Year	2020	Publication	Applied Physics Letters	Abbreviated Journal	Appl Phys Lett
	Volume	117	Issue	5	Pages	052401
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Recent years have seen a tremendous rise of two-dimensional (2D) magnetic materials, several of which were verified experimentally. However, most of the theoretical predictions to date rely on ab initio methods, at zero temperature and fluctuation-free, while one certainly expects detrimental quantum fluctuations at finite temperatures. Here, we present the solution of the quantum Heisenberg model for honeycomb/hexagonal lattices with anisotropic exchange interaction up to third nearest neighbors and in an applied field in arbitrary direction, which answers the question whether long-range magnetization can indeed survive in the ultrathin limit of materials, up to which temperature, and what the characteristic excitation (magnon) frequencies are, all essential to envisaged applications of magnetic 2D materials. We find that long-range magnetic order persists at finite temperature for materials with overall easy-axis anisotropy. We validate the calculations on the examples of monolayers CrI3, CrBr3, and MnSe2. Moreover, we provide an easy-to-use tool to calculate Curie temperatures of new 2D computational materials.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000559330100001	Publication Date	2020-08-03
	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	4	Times cited	8	Open Access
	Notes	; This work was supported by the Research Foundation-Flanders (FWO) and the special research funds of the University of Antwerp (BOF-UA). ;			Approved	Most recent IF: 4; 2020 IF: 3.411
	Call Number	UA @ admin @ c:irua:171176			Serial	6445
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	Author	Bizindavyi, J.; Verhulst, A.S.; Sorée, B.; Groeseneken, G.
	Title	Signature of ballistic band-tail tunneling current in tunnel FET			Type	A1 Journal article
	Year	2020	Publication	Ieee Transactions On Electron Devices	Abbreviated Journal	Ieee T Electron Dev
	Volume	67	Issue	8	Pages	3486-3491
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	To improve the interpretation of the tunnel field-effect transistor (TFET) measurements, we theoretically identify the signatures of the ballistic band-tail (BT) tunneling (BTT) current in the transfer and output characteristics of the TFETs. In particular, we demonstrate that the temperature dependence of a BTT-dominated subthreshold swing (SS) is in agreement with the reported experimental results. We explain how the temperature dependence of the output characteristics can be used to distinguish between a current dominated by BTT and a current dominated by trap-assisted tunneling. Finally, we propose an expression that relates the energetic extension of the quasi-extended BT states in the bandgap to the onset voltage for tunneling.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000552976100072	Publication Date	2020-07-03
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0018-9383	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.1	Times cited		Open Access
	Notes	; This work was supported by imec's Industrial Affiliation Program. ;			Approved	Most recent IF: 3.1; 2020 IF: 2.605
	Call Number	UA @ admin @ c:irua:171189			Serial	6601
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	Author	Kenawy, A.; Magnus, W.; Milošević, M.V.; Sorée, B.
	Title	Voltage-controlled superconducting magnetic memory			Type	A1 Journal article
	Year	2019	Publication	AIP advances T2 – 64th Annual Conference on Magnetism and Magnetic Materials (MMM), NOV 04-08, 2019, Las Vegas, NV	Abbreviated Journal
	Volume	9	Issue	12	Pages	125223
	Keywords	A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
	Abstract	Over the past few decades, superconducting circuits have been used to realize various novel electronic devices such as quantum bits, SQUIDs, parametric amplifiers, etc. One domain, however, where superconducting circuits fall short is information storage. Superconducting memories are based on the quantization of magnetic flux in superconducting loops. Standard implementations store information as magnetic flux quanta in a superconducting loop interrupted by two Josephson junctions (i.e., a SQUID). However, due to the large inductance required, the size of the SQUID loop cannot be scaled below several micrometers, resulting in low-density memory chips. Here, we propose a scalable memory consisting of a voltage-biased superconducting ring threaded by a half-quantum flux bias. By numerically solving the time-dependent Ginzburg-Landau equations, we show that applying a time-dependent bias voltage in the microwave range constitutes a writing mechanism to change the number of stored flux quanta within the ring. Since the proposed device does not require a large loop inductance, it can be scaled down, enabling a high-density memory technology. (C) 2019 Author(s).
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000515525300002	Publication Date	2019-12-20
	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:167551			Serial	8740
Permanent link to this record



	Author	Bizindavyi, J.; Verhulst, A.S.; Verreck, D.; Sorée, B.; Groeseneken, G.
	Title	Large variation in temperature dependence of band-to-band tunneling current in tunnel devices			Type	A1 Journal article
	Year	2019	Publication	IEEE electron device letters	Abbreviated Journal	Ieee Electr Device L
	Volume	40	Issue	11	Pages	1864-1867
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	The observation of a significant temperature-dependent variation in the ${I}$ – ${V}$ characteristics of tunneling devices is often interpreted as a signature of a trap-assisted-tunneling dominated current. In this letter, we use a ballistic 2D quantum-mechanical simulator, calibrated using the measured temperature-dependent ${I}$ – ${V}$ characteristics of Esaki diodes, to demonstrate that the temperature dependence of band-to-band tunneling (BTBT) current can vary significantly in both Esaki diodes and tunnel FETs. The variation of BTBT current with temperature is impacted by doping concentration, gate voltage, possible presence of a highly-doped pocket at the tunnel junction, and material.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000496192600040	Publication Date	2019-09-05
	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		Open Access
	Notes				Approved	Most recent IF: 3.048
	Call Number	UA @ admin @ c:irua:164636			Serial	6306
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	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.
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	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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