toggle visibility
Search within Results:
Display Options:

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author De Beule, C. url  openurl
  Title Confined quantum systems in topological insulator heterostructures Type Doctoral thesis
  Year 2017 Publication Abbreviated Journal  
  Volume Issue Pages 141 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 (down) ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:147217 Serial 7725  
Permanent link to this record
 

 
Author Lou, W.-K. pdf  openurl
  Title The electrical properties of low low dimensional topological insulators Type Doctoral thesis
  Year 2012 Publication Abbreviated Journal  
  Volume Issue Pages 186 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 (down) ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:158894 Serial 7858  
Permanent link to this record
 

 
Author Vargas Paredes, A.A. url  openurl
  Title Emergent phenomena in superconductors in presence of intraband and cross-band pairing Type Doctoral thesis
  Year 2020 Publication Abbreviated Journal  
  Volume Issue Pages 142 p.  
  Keywords Doctoral thesis; Condensed Matter Theory (CMT)  
  Abstract In this thesis we investigate the emergence of new phenomena in multigap superconductors and multicomponent Ginzburg-Landau theories in the presence of intraband and cross-band pairing. The first part contains a review of emergent phenomena in superconductors with only intraband pairing, in particular the mechanism behind gap resonances which are accompanied by Higgs and Leggett modes. Then we study the gap resonances induced by two-dimensional quantum confinement and describe its spatial profile using the Bogoliubov-de Gennes equations. In the second part we describe the conditions where the cross-band pair formation is feasible. Using the formalism of Green functions we obtain the equations governing the interplay between intraband and cross-band pairing. Also, we derived the Ginzburg-Landau equations considering both intraband and cross-band pairing. Finally, we describe the crossover between the intraband-dominated and crossband-dominated regimes. These two are delimited by a tendency towards a gapless state. When a magnetic field is applied close to the gapless state, we found new arrangements of vortices like square lattices, stripes, labyrinths or of vortex clusters. The experimental signatures and consequences of crosspairing are discussed for MgB2 and Ba0.6K0.4Fe2As2.  
  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 (down) ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:165865 Serial 7899  
Permanent link to this record
 

 
Author Stosic, D. file  openurl
  Title High-performance Ginzburg-Landau simulations of superconductivity Type Doctoral thesis
  Year 2018 Publication Abbreviated Journal  
  Volume Issue Pages 166 p.  
  Keywords Doctoral thesis; Condensed Matter Theory (CMT)  
  Abstract Superconductivity is one of the most important discoveries of the last century. With many applications in physics, engineering, and technology, superconductors are crucial to our way of living. Several material and engineering issues however prevent their widespread usage in everyday life. Comprehensive studies are being directed at these materials and their properties to come up with new technologies that will address these challenges and enhance their superconductive capabilities. In this context, numerical modeling plays an important role in the search of new solutions to existing material and engineering issues. The time-dependent Ginzburg-Landau (TDGL) theory is a powerful predictive tool for modeling the macroscopic behavior of superconductors. However most of the numerical algorithms developed so far are incapable of describing many basic properties of real superconducting devices, and are too slow on current hardware for large-scale numerical simulations necessary for their accurate description. Therefore, the purpose of this thesis is to develop high-performing numerical solutions that can correctly describe material features to be used as modeling tools of laboratory experiments. Some important innovations introduced in this work include the numerical modeling of nonrectangular geometrical shapes with complex electrical and insulating components, the inclusion of dynamic heating of the material, and the description of different types of material inhomogeneities. These encompass the principal features necessary for a complete description of the superconductive physics in real material samples. In this thesis a numerical solution is developed for modeling superconducting thin films and used to study the superconductive properties of three experimental configurations: the dynamics of vortex matter in a Corbino disk, the motion of ultrafast vortices in an hourglass-shaped microbridge, and the photon detection process in a meander-patterned nanowire. Moreover, a numerical solution is developed for modeling three-dimensional superconductors which are studied here for the first time in the type-I superconducting regime. These numerical algorithms are optimized to exploit the computational horsepower of graphics processing units (GPUs) and multicore central-processing unit (CPU) clusters such that they can achieve high-performance and be used to model large-scale problems previously impossible on conventional machines. Several computational tools are also designed to assist with the modeling of superconducting devices. These include a numerical library of the TDGL equations, a novel mechanism for the generation of complex geometries, a closed-form solver to conduct numerical simulations, and a graphics user interface (GUI) to visualize the dynamic behavior of superconductors. The contributions in this thesis ultimately push the boundaries on what is possible in state-of-the-art numerical modeling of superconductivity.  
  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 (down) ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:181141 Serial 8034  
Permanent link to this record
 

 
Author Stosic, D. file  openurl
  Title Numerical simulations of magnetic skyrmions in atomically-thin ferromagnetic films Type Doctoral thesis
  Year 2018 Publication Abbreviated Journal  
  Volume Issue Pages 153 p.  
  Keywords Doctoral thesis; Condensed Matter Theory (CMT)  
  Abstract Moore’s Law has driven the electronics industry for the past half century. However, the doubling of transistors about every two years is beginning to break down, owing to fundamental limits that arise as they approach the atomic length. As a result, the search for new pathways for electronics has become crucial. Among potential candidates, the discovery of magnetic textures known as skyrmions has attracted considerable interest and attention in spintronic technology, which relies on both the electron charge and its spin. The unusual topological and particle-like behavior launched skyrmions into the spotlight of scientific research. Topological protected stability, nanoscale size, and low driving currents needed to move them make skyrmions promising candidates for future consumer nanoelectronics. Recent advances in the field have provided all of the basic functions needed for carrying and processing information. In this thesis, we procure to advance the current understanding of skyrmion physics, and explore their potential to replace conventional electronics technology. First, the fundamental properties and lifetimes of racetrack skyrmions at room temperature are investigated. We discover that skyrmions can easily collapse at the boundary in laterally finite systems, and propose ways to improve their stability for constrained geometries. Then, pinning of single skyrmions on atomic defects of distinct origins are studied. We reveal that the preferred pinning positions depend on the skyrmion size and type of defect being considered, and discuss applications where control of skyrmions by defects is of particular interest. Next, we explore other magnetic configurations that can compete with skyrmions when considering new materials, and describe a previously unseen mechanism for collapse of skyrmions into cycloidal spin backgrounds. Finally, switching and interactions between skyrmions with distinct topologies are reported. We find that skyrmions transition to higher or lower topologies by absorbing a unit spin texture. The interactions between skyrmions of different topological charges can be attractive or repulsive, leading to the formation of arranged clusters. We conclude with a numerical library for simulating magnetic skyrmions in various scenarios.  
  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 (down) ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:181142 Serial 8322  
Permanent link to this record
 

 
Author de Araujo, J.L.B.; Munarin, F.F.; Farias, G.A.; Peeters, F.M.; Ferreira, W.P. url  doi
openurl 
  Title Structure and reentrant percolation in an inverse patchy colloidal system Type A1 Journal article
  Year 2017 Publication Physical Review E Abbreviated Journal  
  Volume 95 Issue 6 Pages 062606  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Two-dimensional systems of inverse patchy colloids modeled as disks with a central charge and having their surface decorated with oppositely pointlike charged patches are investigated using molecular dynamics simulations. The self-assembly of the patchy colloids leads to diverse ground state configurations ranging from crystalline arrangements of monomers to linear clusters, ramified linear clusters and to percolated configurations. Two structural phase diagrams are constructed: (1) as a function of the net charge and area fraction, and (2) as a function of the net charge and the range of the pair interaction potential. An interesting reentrant percolation transition is obtained as a function of the net charge of the colloids. We identify distinct mechanisms that lead to the percolation transition.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000404545700005 Publication Date 2017-06-27  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (down) ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited 5 Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:152628 Serial 8587  
Permanent link to this record
 

 
Author Xiao, Y. openurl 
  Title Theoretical study of the optoelectronic properties of new type 2DEG materials : multilayer graphene and monolayer MoS2 Type Doctoral thesis
  Year 2017 Publication Abbreviated Journal  
  Volume Issue Pages 144 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 (down) ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:144948 Serial 8661  
Permanent link to this record
 

 
Author Taghizadeh Sisakht, E. file  openurl
  Title Tight-binding investigation of the electronic properties of phosphorene and phosphorene nanoribbons Type Doctoral thesis
  Year 2019 Publication Abbreviated Journal  
  Volume Issue Pages 150 p.  
  Keywords Doctoral thesis; Condensed Matter Theory (CMT)  
  Abstract abstract not available  
  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 (down) ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:166195 Serial 8670  
Permanent link to this record
 

 
Author Nakhaee, M. url  openurl
  Title Tight-binding model for two-dimensional materials Type Doctoral thesis
  Year 2020 Publication Abbreviated Journal  
  Volume Issue Pages 139 p.  
  Keywords Doctoral thesis; Condensed Matter Theory (CMT)  
  Abstract abstract not available  
  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 (down) ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:166134 Serial 8671  
Permanent link to this record
 

 
Author Vizarim, N.P. url  openurl
  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 (down) 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 Hassani, H. url  openurl
  Title First-principles study of polarons in WO₃ Type Doctoral thesis
  Year 2023 Publication Abbreviated Journal  
  Volume Issue Pages 181 p.  
  Keywords Doctoral thesis; Condensed Matter Theory (CMT)  
  Abstract Polarons are quasiparticles emerging in materials from the interaction of extra charge carriers with the surrounding atomic lattice. They appear in a wide va- riety of compounds and can have a profound impact on their properties, making the concept of a polaron a central and ubiquitous topic in material science. Al- though the concept is known for about 75 years, the origin of polarons is not yet fully elucidated. This thesis focuses on WO 3 as a well-known prototypical system for studying polarons, which inherent polaronic nature is linked to its remark- able electrical and chromic properties. The primary objective of this research is to provide a comprehensive atomistic description and understanding of polaron formation in WO 3 using first-principles density functional theory (DFT) calcula- tions. Additionally, the investigation explores the interactions between polarons and the possibility of bipolaron formation. Following a systematic strategy, we first extensively analyze the dielectric and lattice dynamical properties of WO 3 in both the room-temperature P 2 1 /n and ground-state P 2 1 /c phases. Our specific focus is on characterizing the zone-center phonons, which serve as the founda- tion for identifying the phonon modes involved in the polaron formation and charge localization process. Subsequently, we examine the impact of structural distortions on the electronic structure of WO 3 to elucidate the interplay between structural distortions and electronic properties, thereby laying the groundwork for understanding electron-phonon couplings. By incorporating these critical fac- tors, we address our primary research goals. The most common explanation for the polaron formation is associated with the electrostatic screening of the extra charge by the polarizable lattice. Here, we show that, even in ionic crystals, this is not necessarily the case. We demonstrate that polarons in this compound arise primarily from non-polar atomic distortions. We then unveil that this unexpected behavior originates from the undoing of distortive atomic motions, which lowers the bandgap. As such, we coin the name of anti-distortive polaron and validate its appearance through a simple quantum-dot model, in which charge localization is the result of balancing structural, electronic, and confinement energy costs. Then, we also study the polaron-polaron interaction and present the formation of the antiferromagnetic W 4+ bipolaronic state with relatively large formation energy. Our analysis of the W 4+ bipolaronic distortions on the global structure reveals the same behavior as in experiments where the highly distorted monoclinic phase transforms into a tetragonal phase as a function of doping. Additionally, leveraging our previous findings on asymmetric polaronic distortion and examin- ing different merging orientations, we stabilize the antiferromagnetic W 5+ -W 5+ bipolaronic state with an energy lower than the W 4+ state. This thesis clari- fies the formation of unusual medium-size 2D polarons and bipolarons in WO3,which might be relevant to the whole family of ABO 3 perovskites, to which WO 3 is closely related. The simplicity of the concept provides also obvious guidelines for tracking similar behavior in other families of compounds.  
  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 (down) ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:198169 Serial 8868  
Permanent link to this record
 

 
Author Hasnat Rubel, A. file  openurl
  Title Theoretical characterization and optimization of nano-engineered superconducting scanning probe tip Type Doctoral thesis
  Year 2023 Publication Abbreviated Journal  
  Volume Issue Pages viii, 145 p.  
  Keywords Doctoral thesis; Engineering sciences. Technology; Condensed Matter Theory (CMT)  
  Abstract Using state-of-the-art simulation methods, we optimized the performance of nanoscale superconducting scanning probe tips for advanced spatial imaging of magnetic fields. The systematic studies of the tips’ static properties as a function of the tilted magnetic field, geometric parameters, and material parameters were carried out. The sensitivity of different superconducting quantum interference devices (SQUIDs) to the magnetic field emanating from the magnetic nanoparticle, where the location of a magnetic nanoparticle is considered below the primary loop's center, was examined as a function of the primary and secondary loop dimensions. The main objective of the research was to characterize and optimize the performance of a nano-sized SQUID-on-tip (SOT) device. Optimal SOT sensitivity was sought, for different loop sizes, arm linewidth, and lead dimensions. Moreover, we revealed that a constriction in the loop arms of the SOT can substantially improve the sensitivity of the device. Finally, the properties of the theta-SOT device were examined in the presence of in-plane and out-of-plane magnetic field components, enabling nanoscale imaging of 3D distributions of the magnetic field. Altogether, the obtained results deliver an engineering solution for the optimum performance of the SOT device in desired conditions.  
  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 (down) ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:199494 Serial 8942  
Permanent link to this record
 

 
Author Jorissen, B.; Covaci, L.; Partoens, B. url  doi
openurl 
  Title Comparative analysis of tight-binding models for transition metal dichalcogenides Type A1 Journal article
  Year 2024 Publication SciPost physics core Abbreviated Journal  
  Volume 7 Issue 1 Pages 004-30  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract We provide a comprehensive analysis of the prominent tight-binding (TB) models for transition metal dichalcogenides (TMDs) available in the literature. We inspect the construction of these TB models, discuss their parameterization used and conduct a thorough comparison of their effectiveness in capturing important electronic properties. Based on these insights, we propose a novel TB model for TMDs designed for enhanced computational efficiency. Utilizing MoS2 as a representative case, we explain why specific models offer a more accurate description. Our primary aim is to assist researchers in choosing the most appropriate TB model for their calculations on TMDs.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date 2024-02-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (down) ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access Not_Open_Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:202983 Serial 9012  
Permanent link to this record
 

 
Author Reijniers, J.; Partoens, B.; Peremans, H. openurl 
  Title Noise-resistant correlation-based alignment of head-related transfer functions for high-fidelity spherical harmonics representation Type P3 Proceeding
  Year 2023 Publication Abbreviated Journal  
  Volume Issue Pages  
  Keywords P3 Proceeding; Engineering sciences. Technology; Engineering Management (ENM); Condensed Matter Theory (CMT)  
  Abstract It is standard practice in virtual reality applications to synthesize binaural audio based on a discrete set of directionally-dependent head-related impulse responses (HRIRs). This set of HRIRs is often time-aligned in a pre-processing step, to allow for high-fidelity interpolation between HRIRs corresponding with neighbouring directions. The fidelity of this operation depends on the similarity of neighbouring aligned HRIRs. The pairwise quality of similarity makes it a difficult criterion to optimize globally and consequently one often resorts to alignment methods based on a specific feature that can be extracted for each HRIR separately, e.g., the first-onset of the peak or the group delay. However, such proxies for similarity are very sensitive to noise and therefore require a high signal-to-noise ratio, which makes them less suitable for processing HRIRs acquired outside an anechoic room. In this paper, we advance a novel alignment method, which maximizes the similarity – defined as the correlation between the full-length HRIRs – between neighbouring aligned HRIRs for all directions at once. We show that this correlation-based alignment procedure outperforms the first-onset alignment with regards to the fidelity of the spherical harmonics representation of both the spectral and interaural time difference (ITD) information, when tested on the KEMAR HRIR and six human HRIRs. Finally, we show that the correlation-based alignment is more robust to noise.  
  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 (down) ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:199714 Serial 9062  
Permanent link to this record
 

 
Author Jorissen, B.; Fernandes, L. openurl 
  Title Simple systems, complicated physics : an interview with Nir Navon Type Editorial
  Year 2023 Publication Belgian journal of physics Abbreviated Journal  
  Volume 1 Issue 6 Pages 4-5  
  Keywords Editorial; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT)  
  Abstract The EPS Antwerp Young Minds (AYM) invited Prof. Nir Navon (Yale University) to hold a colloquium for the physics department. For an audience of students and researchers, Prof. Navon presented recent advances in ultracold quantum matter and research from his own lab. His experimental work paves the way to make toy models used by theorists a reality. We sat down afterwards to discuss ultracold physics, box traps and setting up a lab from scratch.  
  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 (down) ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:202673 Serial 9090  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print

Save Citations:
Export Records: