Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 21 for “"Quasicrystal"”.
-
Observing the 2D Bose glass in an optical quasicrystal
Quasicrystals are a class of materials that are long-range ordered yet not periodic. These unique features make them a fascinating middle ground between order and disorder, thus providing an ideal platform for studying a wealth of physical phenomena. This thesis contains three experimental works …
-
Navigating the Intermetallic Landscape: From Quasicrystal Approximants to High Pressure Crystal Chemistry
… classical Laves phases, and a decagonal quasicrystal approximant. Their formation and bonding is understood through comprehensive analysis of their electronic structure using density functional theory. Similarly, it is possible to add further complexity by applying external pressure, …
-
Phases and non-equilibrium dynamics of ultracold bosons in an optical quasicrystal
… concerns the physics of ultracold bosons in quasicrystalline lattices, studied by means of quantum simulation using ultracold 39K atoms loaded to an eight-fold rotationally symmetric optical quasicrystal. Quasicrystalline and quasiperiodic systems, thanks to their long-range order and lack of …
-
Phase Formation, Liquid Structure, and Physical Properties of Amorphous- and Quasicrystal-forming Alloys
Since the discovery of quasicrystals in 1985 and the development of commercially viable bulk metallic glasses: BMGs) in the mid 1990's a great deal of attention has been given to the characterization of new alloys with desirable properties, such as larger amorphous casting thickness, higher …
-
Decagonal quasicrystals in the Al(Si)-Cu-Co alloy system
We have found four different decagonal quasicrystals in the Al65Cu20Co 15 alloy system. They have different periodicities along the tenfold axis, namely, 0.4, 0.8, 1.2 and 1.6nm. This suggests that the decagonal quasicrystal might have a fundamental structure with periodicity of 0.4nm, the other …
-
Phase Transitions in driven 1D and Quasi-Periodic 2D Optical Lattices
… a two dimensional Bose glass state in an optical quasicrystal. Quasicrystalline patterns posses long-range order but lack periodicity. This places them in the spectrum of materials between clean, ordered crystals and disordered, amorphous solids. They share properties of both disordered structures …
-
Studies on Aperiodic and Quasiperiodic Crystals
… relaxation it was found that the one-component quasicrystal undergoes a structural transition to an aperiodic crystal near $\rho \cong$ 1.03. In the binary quasicrystal there was not a pronounced structural transition, but rather local regions of stability and instability. In both the one- and …
-
Phase transitions in quasiperiodic and driven optical lattices
… apply this tool in two areas: the simulation of quasicrystalline materials with a novel lattice geometry, and the use of Floquet driving to engineer behaviours qualitatively different from static systems. In particular I will present our work using periodic driving to make a continuous quantum …
-
Trapped-modes, slow light and collective resonances in metamaterials
… collective effects are studied in quasicrystal hole arrays and it is demonstrated that non-resonant scatterers can lead to strong lattice resonances and extraordinary transmission even in the case of quasi-periodicity. Microwave and optical quasicrystal patterns exhibit similar …
-
Quantum simulation beyond periodicity: A theoretical study of the many-body and topological properties of quasiperiodic systems
Quasicrystals are intriguing materials that lie at the border between periodic and disordered matter. Their atomic structure exhibits fully long-range ordered, yet never-repeating structures. As such, they inherit properties from both periodic and disordered materials, and are for instance …
-
GROWTH OF SILICA-BASED NANOPARTICLES: CONTROLLING STRUCTURE AND FUNCTION
… multicompartment, cubic, and dodecagonal quasicrystalline. The mechanism driving the structural transition between cubic crystalline and dodecagonal quasicrystalline mesoporous silica nanoparticles is investigated. Control of nanoparticle size down to a single tiling unit (< 30 nm), allows …
-
Self-Consistent Study of Topological Superconductivity in Two-Dimensional Quasicrystals
… the recent discovery of superconductivity in a quasicrystal (QC), we investigate the occurrence of TSC in two-dimensional QCs. Although QCs present Bragg peaks, they have no periodicity. We generalize a tight-binding model for TSC in two dimensions, which was originally proposed for square …
-
Computational Study of Low-friction Quasicrystalline Coatings via Simulations of Thin Film Growth of Hydrocarbons and Rare Gases
Quasicrystalline compounds (QC) have been shown to have lower friction compared to other structures of the same constituents. The abscence of structural interlocking when two QC surfaces slide against one another yields the low friction. To use QC as low-friction coatings in combustion engines …
-
Three-dimensional nanofabrication with elastomeric phase mask
… elastomeric phase masks with five fold, Penrose quasicrystalline layouts. Confocal imaging, computational studies and 3D reconstructions reveal the essential aspects of the flow of light through these quasicrystal masks. The resulting nanostructures show interesting features, including …
-
Mocking quantum mechanics: Semiclassical and machine-learning approaches to frustrated magnetism
… report studies on the localisation properties of quasicrystals; namely, the discovery of thermodynamic universality not described by the usual power laws in one-dimensional quasiperiodic models, and of a two-dimensional quasicrystal in which localised and partially extended states coexist without …
-
Characterization of novel microstructures in Al-Fe-V-Si and Al-Fe-V-Si-Y alloys processed at intermediate cooling rates
… of a structural relationship to the icosahedral quasicrystalline (QC) phase (it is a QC approximant) and a further relationship to the more desirable α-Al12(Fe/V)3Si phase, which is also a QC approximant. The analysis confirmed the findings of earlier studies in this system, which suggested the …
-
Phase behaviors of ABAC tetrablock terpolymers
… near the order-disorder boundary. A dodecagonal quasicrystalline (QC) phase has been identified to occur as an intermediate state between the simple hexagonal order (P6/mmm) and the Frank-Kasper σ-phase ( P /mnm 42 ) before the sample disorders, with THEX < TQC < Tσ < TODT. The TEM results reveal …
-
Physics of Hexagonal Limit-Periodic Phases: Thermodynamics, Formation and Vibrational Modes
<p>Limit-periodic (LP) structures exhibit a type of nonperiodic order yet to be found in a natural material. A recent result in tiling theory, however, has shown that LP order can spontaneously emerge in a two-dimensional (2D) lattice model with nearest-and next-nearest-neighbor interactions. In …
-
Ultracold atoms for synthetic one-dimensional quasicrystals
Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2025-03-28 without embargo terms
Page 1 of 2