| Records |
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 |
Verreck, D.; Van de Put, M.; Sorée, B.; Verhulst, A.S.; Magnus, W.; Vandenberghe, W.G.; Collaert, N.; Thean, A.; Groeseneken, G. |
| Title |
Quantum mechanical solver for confined heterostructure tunnel field-effect transistors |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
| Volume |
115 |
Issue |
5 |
Pages |
053706-53708 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Heterostructure tunnel field-effect transistors (HTFET) are promising candidates for low-power applications in future technology nodes, as they are predicted to offer high on-currents, combined with a sub-60 mV/dec subthreshold swing. However, the effects of important quantum mechanical phenomena like size confinement at the heterojunction are not well understood, due to the theoretical and computational difficulties in modeling realistic heterostructures. We therefore present a ballistic quantum transport formalism, combining a novel envelope function approach for semiconductor heterostructures with the multiband quantum transmitting boundary method, which we extend to 2D potentials. We demonstrate an implementation of a 2-band version of the formalism and apply it to study confinement in realistic heterostructure diodes and p-n-i-n HTFETs. For the diodes, both transmission probabilities and current densities are found to decrease with stronger confinement. For the p-n-i-n HTFETs, the improved gate control is found to counteract the deterioration due to confinement. (C) 2014 AIP Publishing LLC. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000331645900040 |
Publication Date |
2014-02-05 |
| 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 |
15 |
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; 2014 IF: 2.183 |
| Call Number |
UA @ lucian @ c:irua:115825 |
Serial |
2780 |
| Permanent link to this record |
| |
|
| |
| Author |
Verreck, D.; Van de Put, M.L.; Verhulst, A.S.; Sorée, B.; Magnus, W.; Dabral, A.; Thean, A.; Groeseneken, G. |
| Title |
15-band spectral envelope function formalism applied to broken gap tunnel field-effect transistors |
Type |
P1 Proceeding |
| Year |
2015 |
Publication |
18th International Workshop On Computational Electronics (iwce 2015) |
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
|
| Keywords |
P1 Proceeding; Condensed Matter Theory (CMT) |
| Abstract |
A carefully chosen heterostructure can significantly boost the performance of tunnel field-effect transistors (TFET). Modelling of these hetero-TFETs requires a quantum mechanical (QM) approach with an accurate band structure to allow for a correct description of band-to-band-tunneling. We have therefore developed a fully QM 2D solver, combining for the first time a full zone 15-band envelope function formalism with a spectral approach, including a heterostructure basis set transformation. Simulations of GaSb/InAs broken gap TFETs illustrate the wide body capabilities and transparant transmission analysis of the formalism. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
Ieee |
Place of Publication |
New york |
Editor |
|
| Language |
|
Wos |
000380398200055 |
Publication Date |
2015-10-26 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
978-0-692-51523-5 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:134998 |
Serial |
4131 |
| Permanent link to this record |
| |
|
| |
| Author |
Verreck, D.; Verhulst, A.S.; Sorée, B.; Collaert, N.; Mocuta, A.; Thean, A.; Groeseneken, G. |
| Title |
Improved source design for p-type tunnel field-effect transistors : towards truly complementary logic |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
105 |
Issue |
24 |
Pages |
243506 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Complementary logic based on tunnel field-effect transistors (TFETs) would drastically reduce power consumption thanks to the TFET's potential to obtain a sub-60 mV/dec subthreshold swing (SS). However, p-type TFETs typically do not meet the performance of n-TFETs for direct bandgap III-V configurations. The p-TFET SS stays well above 60 mV/dec, due to the low density of states in the conduction band. We therefore propose a source configuration in which a highly doped region is maintained only near the tunnel junction. In the remaining part of the source, the hot carriers in the exponential tail of the Fermi-Dirac distribution are blocked by reducing the doping degeneracy, either with a source section with a lower doping concentration or with a heterostructure. We apply this concept to n-p-i-p configurations consisting of In0.53Ga0.47As and an InP-InAs heterostructure. 15-band quantum mechanical simulations predict that the configurations with our source design can obtain sub-60 mV/dec SS, with an on-current comparable to the conventional source design. (C) 2014 AIP Publishing LLC. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000346643600076 |
Publication Date |
2014-12-17 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0003-6951;1077-3118; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.411 |
Times cited |
10 |
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: 3.411; 2014 IF: 3.302 |
| Call Number |
UA @ lucian @ c:irua:122798 |
Serial |
1568 |
| Permanent link to this record |
| |
|
| |
| Author |
Verreck, D.; Verhulst, A.S.; Sorée, B.; Collaert, N.; Mocuta, A.; Thean, A.; Groeseneken, G. |
| Title |
Non-uniform strain in lattice-mismatched heterostructure tunnel field-effect transistors |
Type |
P1 Proceeding |
| Year |
2016 |
Publication |
Solid-State Device Research (ESSDERC), European Conference
T2 – 46th European Solid-State Device Research Conference (ESSDERC) / 42nd, European Solid-State Circuits Conference (ESSCIRC), SEP 12-15, 2016, Lausanne, SWITZERLAND |
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
412-415 |
| Keywords |
P1 Proceeding; Condensed Matter Theory (CMT) |
| Abstract |
Because of its localized impact on the band structure, non-uniform strain at the heterojunction between lattice-mismatched materials has the potential to significantly enlarge the design space for tunnel-field effect transistors (TFET). However, the impact of a complex strain profile on TFET performance is difficult to predict. We have therefore developed a 2D quantum mechanical transport formalism capable of simulating the effects of a general non-uniform strain. We demonstrate the formalism for the GaAsxSb(1-x)/InyGa(1-y) As system and show that a performance improvement over a lattice-matched reference is indeed possible, allowing for relaxed requirements on the source doping. We also point out that the added design parameter of mismatch is not free, but limited by the desired effective bandgap at the tunnel junction. |
| 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 |
978-1-5090-2969-3 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:138233 |
Serial |
4358 |
| Permanent link to this record |
| |
|
| |
| 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 |
| Permanent link to this record |
| |
|
| |
| Author |
Verreck, D.; Verhulst, A.S.; Van de Put, M.L.; Sorée, B.; Collaert, N.; Mocuta, A.; Thean, A.; Groeseneken, G. |
| Title |
Uniform strain in heterostructure tunnel field-effect transistors |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
IEEE electron device letters |
Abbreviated Journal |
Ieee Electr Device L |
| Volume |
37 |
Issue |
37 |
Pages |
337-340 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Strain can strongly impact the performance of III-V tunnel field-effect transistors (TFETs). However, previous studies on homostructure TFETs have found an increase in ON-current to be accompanied with a degradation of subthreshold swing. We perform 30-band quantum mechanical simulations of staggered heterostructure p-n-i-n TFETs submitted to uniaxial and biaxial uniform stress and find the origin of the subthreshold degradation to be a reduction of the density of states in the strained case. We apply an alternative configuration including a lowly doped pocket in the source, which allows to take full benefit of the strain-induced increase in ON-current. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000372372100026 |
Publication Date |
2016-01-27 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0741-3106 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.048 |
Times cited |
17 |
Open Access |
|
| Notes |
; This work was supported by the imec Industrial Affiliation Program. The work of D. Verreck was supported by the Agency for Innovation by Science and Technology in Flanders. The review of this letter was arranged by Editor Z. Chen. ; |
Approved |
Most recent IF: 3.048 |
| Call Number |
UA @ lucian @ c:irua:133207 |
Serial |
4271 |
| Permanent link to this record |
| |
|
| |
| Author |
Verreck, D.; Verhulst, A.S.; Van de Put, M.L.; Sorée, B.; Magnus, W.; Collaert, N.; Mocuta, A.; Groeseneken, G. |
| Title |
Self-consistent 30-band simulation approach for (non-)uniformly strained confined heterostructure tunnel field-effect transistors |
Type |
P1 Proceeding |
| Year |
2017 |
Publication |
Simulation of Semiconductor Processes and, Devices (SISPAD)AND DEVICES (SISPAD 2017) |
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
29-32 |
| Keywords |
P1 Proceeding; Condensed Matter Theory (CMT) |
| Abstract |
Heterostructures of III-V materials under a mechanical strain are being actively researched to enhance the performance of the tunnel field-effect transistor (TFET). In scaled III-V device structures, however, the interplay between the effects of strain and quantum confinement on the semiconductor band structure and hence the performance is highly non-trivial. We have therefore developed a computationally efficient quantum mechanical simulator Pharos, which enables self-consistent full-zone k.p-based simulations of III-V TFETs under a general non-uniform strain. We present the self-consistent procedure and demonstrate it on confined staggered bandgap GaAs0.5Sb0.5/In0.53Ga0.47As TFETs. We find a large performance degradation due to size-induced quantum confinement compared to non-confined devices. We show that some performance can be regained either by applying a uniform biaxial tensile strain or through the non-uniform strain profile at a lattice-mismatched heterostructure. |
| 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 |
978-4-86348-610-2 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:149949 |
Serial |
4978 |
| Permanent link to this record |
| |
|
| |
| 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 |
| Permanent link to this record |
| |
|
| |
| Author |
Vieira De Castro, L. |
| Title |
Properties of quasi particles on two dimensional materials and related structures |
Type |
Doctoral thesis |
| Year |
2019 |
Publication |
|
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
79 p. |
| Keywords |
Doctoral thesis; Condensed Matter Theory (CMT) |
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
|
Publication Date |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Additional Links |
UA library record |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ admin @ c:irua:161999 |
Serial |
5424 |
| Permanent link to this record |
| |
|
| |
| Author |
Villarreal, R.; Lin, P.-C.; Faraji, F.; Hassani, N.; Bana, H.; Zarkua, Z.; Nair, M.N.; Tsai, H.-C.; Auge, M.; Junge, F.; Hofsaess, H.C.; De Gendt, S.; De Feyter, S.; Brems, S.; Ahlgren, E.H.; Neyts, E.C.; Covaci, L.; Peeters, F.M.; Neek-Amal, M.; Pereira, L.M.C. |
| Title |
Breakdown of universal scaling for nanometer-sized bubbles in graphene |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Nano Letters |
Abbreviated Journal |
Nano Lett |
| Volume |
21 |
Issue |
19 |
Pages |
8103-8110 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
We report the formation of nanobubbles on graphene with a radius of the order of 1 nm, using ultralow energy implantation of noble gas ions (He, Ne, Ar) into graphene grown on a Pt(111) surface. We show that the universal scaling of the aspect ratio, which has previously been established for larger bubbles, breaks down when the bubble radius approaches 1 nm, resulting in much larger aspect ratios. Moreover, we observe that the bubble stability and aspect ratio depend on the substrate onto which the graphene is grown (bubbles are stable for Pt but not for Cu) and trapped element. We interpret these dependencies in terms of the atomic compressibility of the noble gas as well as of the adhesion energies between graphene, the substrate, and trapped atoms. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000709549100026 |
Publication Date |
2021-09-14 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1530-6984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
12.712 |
Times cited |
12 |
Open Access |
OpenAccess |
| Notes |
|
Approved |
Most recent IF: 12.712 |
| Call Number |
UA @ admin @ c:irua:184137 |
Serial |
6857 |
| Permanent link to this record |
| |
|
| |
| Author |
Villegas, C.E.P.; Tavares, M.R.S.; Hai, G.-Q.; Peeters, F.M. |
| Title |
Sorting the modes contributing to guidance in strain-induced graphene waveguides |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
New journal of physics |
Abbreviated Journal |
New J Phys |
| Volume |
15 |
Issue |
|
Pages |
023015-11 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We propose a simple way of probing the number of modes contributing to the channeling in graphene waveguides which are formed by a gauge potential produced by mechanical strain. The energy mode structure for both homogeneous and non-homogeneous strain regimes is carefully studied using the continuum description of the Dirac equation. We found that high strain values privilege negative (instead of positive) group velocities throughout the guidance, sorting the types of modes flowing through it. We also show how the effect of a substrate-induced gap competes against the strain. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Bristol |
Editor |
|
| Language |
|
Wos |
000314868000002 |
Publication Date |
2013-02-08 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1367-2630; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.786 |
Times cited |
7 |
Open Access |
|
| Notes |
; This work was supported by FAPESP, CNPq and the Flemish Science Foundation (FWO-VI). ; |
Approved |
Most recent IF: 3.786; 2013 IF: 3.671 |
| Call Number |
UA @ lucian @ c:irua:107667 |
Serial |
3056 |
| Permanent link to this record |
| |
|
| |
| Author |
Vinchurkar, S.; De Backer, L.; Vos, W.; Van Holsbeke, C.; de Backer, J.; de Backer, W. |
| Title |
A case series on lung deposition analysis of inhaled medication using functional imaging based computational fluid dynamics in asthmatic patients : effect of upper airway morphology and comparison with in vivo data |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Inhalation Toxicology |
Abbreviated Journal |
Inhal Toxicol |
| Volume |
24 |
Issue |
2 |
Pages |
81-88 |
| Keywords |
A1 Journal article; Pharmacology. Therapy; Biophysics and Biomedical Physics; Condensed Matter Theory (CMT); Laboratory Experimental Medicine and Pediatrics (LEMP) |
| Abstract |
Context: Asthma affects 20 million Americans resulting in an economic burden of approximately $18 billion in the US alone (Allergies and Asthma Foundation 2000; National Center for Environmental Health (NCEH) 1999). Research studies based on differences in patient-specific airway morphology for asthma and the associated effect on deposition of inhaled aerosols are currently not available in the literature. Therefore, the role of morphological variations such as upper airway (extrathoracic) occlusion is not well documented. Objective: Functional imaging based computational fluid dynamics (CFD) of the respiratory airways for five asthmatic subjects is performed in this study using computed tomography (CT) based patient-specific airway models and boundary conditions. Methods: CT scans for 5 asthma patients were used to reconstruct 3D lung models using segmentation software. An averaged inhalation profile and patient-specific lobar flow distribution were used to perform the simulation. The simulations were used to obtain deposition for BDP/Formoterol (R) HFA pMDI in the patient-specific airway models. Results: The lung deposition obtained using CFD was in excellent agreement with available in vivo data using the same product. Specifically, CFD resulted in 30% lung deposition, whereas in vivo lung deposition was reported to be approximately 31%. Conclusion: It was concluded that a combination of patient-specific airway models and lobar boundary conditions can be used to obtain accurate lung deposition estimates. Lower lung deposition can be expected for patients with higher extrathoracic resistance. Novel respiratory drug delivery devices need to accommodate population subgroups based on these morphological and anatomical differences in addition to subject age. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
| Language |
|
Wos |
000299744800001 |
Publication Date |
2012-01-20 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0895-8378;1091-7691; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.751 |
Times cited |
36 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 1.751; 2012 IF: 1.894 |
| Call Number |
UA @ lucian @ c:irua:96238 |
Serial |
286 |
| Permanent link to this record |
| |
|
| |
| Author |
Vizarim, N.P. |
| Title |
Dynamic behavior of Skyrmions under the influence of periodic pinning in chiral magnetic infinite thin films |
Type |
Doctoral thesis |
| Year |
2023 |
Publication |
|
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
212 p. |
| Keywords |
Doctoral thesis; Condensed Matter Theory (CMT) |
| Abstract |
The miniaturization of transistors for application in new processors and logic devices poses a significant challenge in the field of materials. Spintronics, which relies on controlled movement of magnetic nanostructures, offers a promising solution. Among the candidates, magnetic skyrmions are considered one of the most promising. These chiral spin structures, characterized by topological protection and enhanced stability compared to vortices or magnetic bubbles, have been extensively studied. To advance in the control of skyrmion motion, essential for practical applications, we investigated their dynamic behavior in a two-dimensional chiral magnet at zero temperature. Our study focused on the influence of periodic arrays of pinning centers. The simulations considered skyrmions as point-like particles considering the following interactions: skyrmion-skyrmion interactions, interactions with pinning center arrays, a current of polarized spins, and the Magnus force. We conducted calculations for scenarios involving a single skyrmion as well as different skyrmion density values in the material. The aim was to explore possibilities for controlled skyrmion motion, investigate different dynamic regimes, and examine collective effects. The results demonstrate that by adjusting the size, strength, and density of the pinning centers, we can effectively control the motion of individual skyrmions and manage the flow of multiple skyrmions. Furthermore, we discovered that periodic arrays of pinning centers can facilitate topological selection when different species of skyrmions with distinct Magnus components are present. Employing alternating currents, we observed the significant role of the ratchet effect in the skyrmion dynamics. By fine-tuning the amplitudes of the alternating currents, we achieved direct and controlled motion of skyrmions in specific directions. These findings hold potential for advancing our understanding of skyrmion dynamics and can inspire future technological applications involving these quasi-particles. Overall, we anticipate that our results will be valuable to the scientific community, contributing to a deeper comprehension of skyrmion dynamics and paving the way for future technological applications. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
|
Publication Date |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Additional Links |
UA library record |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ admin @ c:irua:198101 |
Serial |
8852 |
| Permanent link to this record |
| |
|
| |
| Author |
Vizarim, N.P.; Souza, J.C.B.; Reichhardt, C.J.O.; Reichhardt, C.; Milošević, M.V.; Venegas, P.A. |
| Title |
Soliton motion in skyrmion chains : stabilization and guidance by nanoengineered pinning |
Type |
A1 Journal article |
| Year |
2022 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
105 |
Issue |
22 |
Pages |
224409-224412 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Using a particle-based model we examine the depinning motion of solitons in skyrmion chains in quasi -onedimensional (1D) and two-dimensional (2D) systems containing embedded 1D interfaces. The solitons take the form of a particle or hole in a commensurate chain of skyrmions. Under an applied drive, just above a critical depinning threshold, the soliton moves with a skyrmion Hall angle of zero. For higher drives, the entire chain depins, and in a 2D system we observe that both the solitons and chain move at zero skyrmion Hall angle and then transition to a finite skyrmion Hall angle as the drive increases. In a 2D system with a 1D interface that is at an angle to the driving direction, there can be a reversal of the sign of the skyrmion Hall angle from positive to negative. Our results suggest that solitons in skyrmion systems could be used as information carriers in racetrack geometries that would avoid the drawbacks of finite skyrmion Hall angles. The soliton states become mobile at significantly lower drives than the depinning transition of the skyrmion chains themselves. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000823038900004 |
Publication Date |
2022-06-16 |
| 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 |
2 |
Open Access |
OpenAccess |
| Notes |
|
Approved |
Most recent IF: 3.7 |
| Call Number |
UA @ admin @ c:irua:189671 |
Serial |
7209 |
| Permanent link to this record |
| |
|
| |
| Author |
Vodolazov, D.; Baelus, B.J.; Peeters, F.M. |
| Title |
Dynamics of the superconducting condensate in the presence of a magnetic field : channelling of vortices in superconducting strips at high currents |
Type |
A1 Journal article |
| Year |
2004 |
Publication |
Physica: C : superconductivity |
Abbreviated Journal |
Physica C |
| Volume |
404 |
Issue |
1-4 |
Pages |
400-404 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
On the basis of the time-dependent Ginzburg-Landau equation we studied the dynamics of the superconducting condensate in a wide two-dimensional sample in the presence of a perpendicular magnetic field and applied current. We could identify two critical currents: the current at which the pure superconducting state becomes unstable (J(c2)(1)) and the current at which the system transits from the resistive state to the superconducting state (J(c1) < J(c2)). The current J(c2) decreases monotonically with external magnetic field, while J(c1) exhibits a maximum at H*. For sufficient large magnetic fields the hysteresis disappears and J(c1) = J(c2) = Jc. In this high magnetic field region and for currents close to Jc the voltage appears as a result of the motion of separate vortices. With increasing current the moving vortices form,channels' with suppressed order parameter along which the vortices can move very fast. This leads to a sharp increase of the voltage. These 'channels' resemble in some respect the phase slip lines which occur at zero magnetic field. (C) 2004 Elsevier B.V. All rights reserved. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000221211500074 |
Publication Date |
2004-02-28 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0921-4534; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.404 |
Times cited |
16 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 1.404; 2004 IF: 1.072 |
| Call Number |
UA @ lucian @ c:irua:95108 |
Serial |
784 |
| Permanent link to this record |
| |
|
| |
| Author |
Vodolazov, D.I.; Peeters, F.M. |
| Title |
Dynamic transitions between metastable states in a superconducting ring |
Type |
A1 Journal article |
| Year |
2002 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
66 |
Issue |
5 |
Pages |
054537-054537,7 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Applying the time-dependent Ginzburg-Landau equations, transitions between metastable states of a superconducting ring are investigated in the presence of an external magnetic field. It is shown that if the ring exhibits several metastable states at a particular magnetic field, the transition from one metastable state to another one is governed by both the relaxation time of the absolute value of the order parameter tau(\psi\) and the relaxation time of the phase of the order parameter tau(phi). We found that the larger the ratio tau(\psi\)/tau(phi), the closer the final state will be to the absolute minimum of the free energy, i.e., the thermodynamic equilibrium. The transition to the final state occurs through a subsequent set of single phase slips at a particular point along the ring. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000177873000143 |
Publication Date |
2002-08-30 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
34 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2002 IF: NA |
| Call Number |
UA @ lucian @ c:irua:94917 |
Serial |
768 |
| Permanent link to this record |
| |
|
| |
| Author |
Vodolazov, D.Y.; Baelus, B.J.; Peeters, F.M. |
| Title |
Stationary-phase slip state in quasi-one-dimensional rings |
Type |
A1 Journal article |
| Year |
2002 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
66 |
Issue |
5 |
Pages |
054531-54536 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The nonuniform superconducting state in a ring in which the order parameter vanishing at one point is studied. This state is characterized by a jump of the phase by pi at the point where the order parameter becomes zero. In uniform rings such a state is a saddle-point state and consequently unstable. However, for nonuniform rings with, e.g., variations of geometrical or physical parameters or with attached wires this state can be stabilized and may be realized experimentally. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000177873000137 |
Publication Date |
2002-10-01 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
29 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2002 IF: NA |
| Call Number |
UA @ lucian @ c:irua:104147 |
Serial |
3152 |
| Permanent link to this record |
| |
|
| |
| Author |
Vodolazov, D.Y.; Berdiyorov, G.; Peeters, F.M. |
| Title |
Negative magnetoresistance in thin superconducting films with parallel orientation of current and magnetic field |
Type |
A1 Journal article |
| Year |
2018 |
Publication |
Physica: C : superconductivity |
Abbreviated Journal |
Physica C |
| Volume |
552 |
Issue |
552 |
Pages |
64-66 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Thin superconducting films can exhibit negative magnetoresistance when an in-plane external magnetic field is aligned parallel with the transport current. We explain this effect as due to appearance of parallel vortices in the plain of the film at the first critical magnetic field H-c1 which leads to an enhancement of the superconducting properties and impedes the motion of the current induced perpendicular vortices. Our theoretical results are based on a numerical solution of the time-dependent and stationary 3D Ginzburg-Landau equations. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000440786600012 |
Publication Date |
2018-07-20 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0921-4534 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.404 |
Times cited |
6 |
Open Access |
|
| Notes |
; The work is supported by the Russian Science Foundation Project No. 17-72-30036 and the Malthusian programme of the Flemish government. ; |
Approved |
Most recent IF: 1.404 |
| Call Number |
UA @ lucian @ c:irua:153067UA @ admin @ c:irua:153067 |
Serial |
5117 |
| Permanent link to this record |
| |
|
| |
| Author |
Vodolazov, D.Y.; Elmuradov, A.; Peeters, F.M. |
| Title |
Critical currents of the phase slip process in the presence of electromagnetic radiation : rectification for time asymmetric ac signal |
Type |
A1 Journal article |
| Year |
2005 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
72 |
Issue |
13 |
Pages |
134509-7 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We studied theoretically the effect of time symmetric and asymmetric electromagnetic (e.m.) radiation on the phase-slip process in superconducting wires in the regime where there is no stimulation of superconductivity. We found that for large amplitudes j(ac) of the symmetric ac signal the value of the lower critical current j(c1)(j(ac)) at which the voltage vanishes in the sample oscillates as a function of j(ac). The amplitude of these oscillations decays with increasing power of the ac signal, and we explain it either by the existence of a maximal current j(c3) beyond which no phase slips can be created or by a weak heat removal from the sample. Applying an asymmetric in time signal (with zero dc current) we show that it may lead to a finite voltage in the system (i.e., ratchet effect). At high enough frequencies the rectified voltage is directly proportional to the frequency of the applied e.m. radiation. These properties resemble in many aspects the behavior of a Josephson junction under e.m. radiation. The differences are mainly connected to the effect of the transport current on the magnitude of the order parameter. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000231564400132 |
Publication Date |
2005-08-09 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
35 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2005 IF: 3.185 |
| Call Number |
UA @ lucian @ c:irua:102721 |
Serial |
543 |
| Permanent link to this record |
| |
|
| |
| Author |
Vodolazov, D.Y.; Golubovic, D.S.; Peeters, F.M.; Moshchalkov, V.V. |
| Title |
Enhancement and decrease of critical current due to suppression of superconductivity by a magnetic field |
Type |
A1 Journal article |
| Year |
2007 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
76 |
Issue |
13 |
Pages |
134505,1-7 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000250619800084 |
Publication Date |
2007-10-05 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
13 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2007 IF: 3.172 |
| Call Number |
UA @ lucian @ c:irua:67347 |
Serial |
1059 |
| Permanent link to this record |
| |
|
| |
| Author |
Vodolazov, D.Y.; Peeters, F.M. |
| Title |
Enhancement of the retrapping current of superconducting microbridges of finite length |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
85 |
Issue |
2 |
Pages |
024508-024508,6 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We theoretically find that the resistance of a superconducting microbridge or nanowire decreases while the retrapping current I(r) for the transition to the superconducting state increases when one suppresses the magnitude of the order parameter vertical bar Delta vertical bar in the attached superconducting leads. This effect is a consequence of the increased energy interval for diffusion of the “hot” nonequilibrium quasiparticles (induced by the oscillations of vertical bar Delta vertical bar in the center of the microbridge) to the leads. The effect is absent in short microbridges (with length less than the coherence length) and it is relatively weak in long microbridges (with length larger than the inelastic relaxation length of the nonequilibrium distribution function). A nonmonotonous dependence of I(r) on the length of the microbridge is predicted. Our results are important for the explanation of the enhancement of the critical current and the appearance of negative magnetoresistance observed in many recent experiments on superconducting microbridges or nanowires. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000298863400005 |
Publication Date |
2012-01-06 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
7 |
Open Access |
|
| Notes |
; This work was supported by the Russian Foundation for Basic Research, Russian Agency of Education, under the Federal Target Programme “Scientific and Educational Personnel of Innovative Russia in 2009-2013” and the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
| Call Number |
UA @ lucian @ c:irua:96235 |
Serial |
1065 |
| Permanent link to this record |
| |
|
| |
| Author |
Vodolazov, D.Y.; Peeters, F.M. |
| Title |
Heating of quasiparticles driven by oscillations of the order parameter in short superconducting microbridges |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
83 |
Issue |
22 |
Pages |
224523-224523,6 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We predict heating of quasiparticles driven by order parameter oscillations in the resistive state of short superconducting microbridges. The finite relaxation time of the magnitude of the order parameter |Δ| and the dependence of the spectral functions both on |Δ| and the supervelocity Q are the origin of this effect. Our results are opposite to those of Aslamazov and Larkin [ Zh. Eks. Teor. Fiz. 70 1340 (1976)] and Schmid et al. [ Phys. Rev. B 21 5076 (1980)] where cooling of quasiparticles was found. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000292218200010 |
Publication Date |
2011-06-29 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
4 |
Open Access |
|
| Notes |
; This work was supported by the Russian Foundation for Basic Research, Russian Agency of Education under the Federal Target Programme “Scientific and educational personnel of innovative Russia in 2009-2013,” Flemish Science Foundation (FWO-Vl), and the Belgian Science Policy (IAP). ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
| Call Number |
UA @ lucian @ c:irua:90924 |
Serial |
1415 |
| Permanent link to this record |
| |
|
| |
| Author |
Vodolazov, D.Y.; Peeters, F.M. |
| Title |
Origin of the hysteresis of the current voltage characteristics of superconducting microbridges near the critical temperature |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
84 |
Issue |
9 |
Pages |
094511 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The current voltage (IV) characteristics of short [with length L less than or similar to xi(T)] and long [L >> xi(T)] microbridges are theoretically investigated near the critical temperature of the superconductor. Calculations are made in the nonlocal (local) limit when the inelastic relaxation length due to electron-phonon interactions L(in) = (D tau(in))(1/2) is larger (smaller) than the temperature-dependent coherence length xi(T) (D is the diffusion coefficient, tau(in) is the inelastic relaxation time of the quasiparticle distribution function). We find that, in both limits, the origin of the hysteresis in the IV characteristics is mainly connected with the large time scale over which the magnitude of the order parameter varies in comparison with the time-scale variation of the superconducting phase difference across the microbridge in the resistive state. In the nonlocal limit, the time-averaged heating and cooling of quasiparticles are found in different areas of the microbridge, which are driven, respectively, by oscillations of the order parameter and the electric field. We show that, by introducing an additional term in the time-dependent Ginzburg-Landau equation, it is possible to take into account the cooling effect in the local limit too. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000294920900009 |
Publication Date |
2011-09-14 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
7 |
Open Access |
|
| Notes |
; This work was supported by the Russian Foundation for Basic Research, Russian Agency of Education under the Federal Target Programme“Scientific and educational personnel of innovative Russia in 2009-2013,” the Flemish Science Foundation (FWO-Vl), and the Belgian Science Policy (IAP). ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
| Call Number |
UA @ lucian @ c:irua:105573 |
Serial |
2527 |
| Permanent link to this record |
| |
|
| |
| Author |
Vodolazov, D.Y.; Peeters, F.M. |
| Title |
Rearrangement of the vortex lattice due to instabilities of vortex flow |
Type |
A1 Journal article |
| Year |
2007 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
76 |
Issue |
|
Pages |
014521,1-9 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000248487900119 |
Publication Date |
2007-07-24 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
103 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2007 IF: 3.172 |
| Call Number |
UA @ lucian @ c:irua:69653 |
Serial |
2838 |
| Permanent link to this record |
| |
|
| |
| Author |
Vodolazov, D.Y.; Peeters, F.M. |
| Title |
Stable and metastable states in a mesoscopic superconducting “eight” loop in presence of an external magnetic field |
Type |
A1 Journal article |
| Year |
2004 |
Publication |
Physica: C : superconductivity |
Abbreviated Journal |
Physica C |
| Volume |
400 |
Issue |
3-4 |
Pages |
165-170 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The stable and metastable states of different configurations of a mesoscopic loop in the form of an eight is studied in the presence of a magnetic field. We find that for certain configurations the current is equal to zero for any value of the magnetic field leading to a magnetic field independent superconducting state. The state with fixed phase circulation becomes unstable when the momentum of the superconducting electrons reaches a critical value. At this moment the kinetic energy of the superconducting condensate becomes of the same order as the potential energy of the Cooper pairs and it leads to an instability. Numerical analysis of the time-dependent Ginzburg-Landau equations shows that the absolute value of the order parameter changes gradually at the transition from a state with one phase circulation to another although the vorticity change occurs abruptly. (C) 2003 Elsevier B.V. All rights reserved. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000187726300010 |
Publication Date |
2003-09-17 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0921-4534; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.404 |
Times cited |
5 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 1.404; 2004 IF: 1.072 |
| Call Number |
UA @ lucian @ c:irua:103757 |
Serial |
3142 |
| Permanent link to this record |
| |
|
| |
| Author |
Vodolazov, D.Y.; Peeters, F.M. |
| Title |
Strong influence of nonlocal nonequilibrium effects on the dynamics of the order parameter in a phase-slip center: ring studies |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
81 |
Issue |
18 |
Pages |
184521,1-184521,7 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We study the influence of the inelastic relaxation time τ̃E of the quasiparticle distribution function f(E) on the phase slip process in quasi-one-dimensional superconducting rings at a temperature close to the critical temperature Tc. We find that the initial time of growth of the order parameter |Δ| in the phase slip core after the phase slip is a nonmonotonic function of τ̃E which has a maximum at τ̃E≃τ̃GL=πℏ/8kB(Tc−T) and has a tendency to saturate for large τ̃E⪢τ̃GL. The effective heating of the electron subsystem due to the increase in |Δ| in the phase slip center together with the above effect result in a nonmonotonic dependence of the number of subsequent phase slips on τ̃E in rings of relatively large radius (in which each phase slip reduces the current density to a small fraction of its initial value). During the phase slip process the order parameter distribution has two peaks near the phase slip core due to the diffusion of the nonequilibrium quasiparticles from that region. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000278141800100 |
Publication Date |
2010-05-19 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
5 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Belgian Science Policy (IAP). D.Y.V. also acknowledges support from the Russian Foundation for Basic Research, Federal Target Programme “Scientific and scientific-pedagogical personnel of innovative Russia in 2009-2013” and Dynasty Foundation. ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| Call Number |
UA @ lucian @ c:irua:83305 |
Serial |
3182 |
| Permanent link to this record |
| |
|
| |
| Author |
Vodolazov, D.Y.; Peeters, F.M. |
| Title |
Superconducting rectifier based on the asymmetric surface barrier effect |
Type |
A1 Journal article |
| Year |
2005 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
72 |
Issue |
17 |
Pages |
172508,1-4 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000233603500030 |
Publication Date |
2005-11-23 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
32 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2005 IF: 3.185 |
| Call Number |
UA @ lucian @ c:irua:56049 |
Serial |
3365 |
| Permanent link to this record |
| |
|
| |
| Author |
Vodolazov, D.Y.; Peeters, F.M. |
| Title |
Symmetric and asymmetric states in a mesoscopic superconducting wire in the voltage-driven regime |
Type |
A1 Journal article |
| Year |
2007 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
75 |
Issue |
10 |
Pages |
104515,1-4 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000245329100092 |
Publication Date |
2007-03-28 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
6 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2007 IF: 3.172 |
| Call Number |
UA @ lucian @ c:irua:64274 |
Serial |
3400 |
| Permanent link to this record |
| |
|
| |
| Author |
Vodolazov, D.Y.; Peeters, F.M. |
| Title |
Temporary cooling of quasiparticles and delay in voltage response of superconducting bridges after abruptly switching on the supercritical current |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
90 |
Issue |
9 |
Pages |
094504 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We revisit the problem of the dynamic response of a superconducting bridge after abruptly switching on the supercritical current. In contrast to previous theoretical works we take into account spatial gradients and use both the local temperature approach and the kinetic equation for the distribution function of quasiparticles. We find that the temperature dependence of the finite delay time t(d) in the voltage response is model dependent and relatively large t(d) is connected with temporary cooling of quasiparticles during decay of superconducting order parameter vertical bar Delta vertical bar in time. It turns out that the presence of even small inhomogeneities in the bridge or finite length of the homogenous bridge favors a local suppression of vertical bar Delta vertical bar during the dynamic response. It results in a decrease of the delay time, in comparison with the spatially uniform model, due to the diffusion of nonequilibrium quasiparticles from the region with locally suppressed vertical bar Delta vertical bar. In the case when the current density is maximal near the edge of a not very wide bridge the delay time is mainly connected with the time needed for the nucleation (entrance) of the first vortex and t(d) could be tuned by a weak external magnetic field. We also find that a short alternating current pulse (sinusoidlike) with zero time average may result in a nonzero time- averaged voltage response where its sign depends on the phase of the ac current. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000342103600002 |
Publication Date |
2014-09-10 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
2 |
Open Access |
|
| Notes |
; This work was partially supported by the Russian Foundation for Basic Research (Project No. 12-02-00509), by the Ministry of Education and Science of the Russian Federation (the agreement of August 27, 2013, No. 02.B.49.21.0003, between The Ministry of Education and Science of the Russian Federation and Lobachevsky State University of Nizhni Novgorod) and by the European Science Foundation (ESF) within the framework of the activity entitled “Exploring the Physics of Small Devices (EPSD)” (Project No. 4327). ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
| Call Number |
UA @ lucian @ c:irua:119908 |
Serial |
3504 |
| Permanent link to this record |
