Sökning: "Quantum Phase Transitions"
Visar resultat 11 - 15 av 59 avhandlingar innehållade orden Quantum Phase Transitions.
11. Superfluid Phase Transitions in Disordered Systems
Sammanfattning : This thesis presents results from large scale Monte Carlo simulations of systems subject to a superfluid phase transition in the presence of disorder. The simulations are performed by state-of-the-art, collective Monte Carlo algorithms treating phase degrees of freedom in effective models with amplitude fluctuations integrated out. LÄS MER
12. Entanglement and Quantum Computation from a Geometric and Topological Perspective
Sammanfattning : In this thesis we investigate geometric and topological structures in the context of entanglement and quantum computation.A parallel transport condition is introduced in the context of Franson interferometry based on the maximization of two-particle coincidence intensity. LÄS MER
13. Designing and Tuning the Properties of Materials by Quantum Mechanical Calculations
Sammanfattning : In many materials, changes in chemical composition, pressure or temperature can induce metal to insulator transitions. It is recently observed in yttrium hydride, for example, changes from a shiny mirror (YH2) to a transparent window (YH3), which has important technological application in optical devices. LÄS MER
14. Topological Phase Transitions in Magnetic Nanostructures of Dirac Materials
Sammanfattning : Over the past two decades, the discovery of topological Dirac materials, such as topological insulators and semimetals, has defined a new paradigm in condensed matter physics and established new platforms for realizing spin electronic devices and quantum computing. The novel quantum properties of these materials, which are mainly due to the presence of strong spin-orbit coupling, are invariant under topological transformations, making them more resilient to structural disorder, electromagnetic and thermal fluctuations in comparison to the conventional silicon-based materials. LÄS MER
15. Type-II interband quantum dot photodetectors
Sammanfattning : Photon detectors based on single-crystalline materials are of great interest for high performance imaging applications due to their low noise and fast response. The major detector materials for sensing in the long-wavelength infrared (LWIR) band (8-14 µm) are currently HgCdTe (MCT) and AlGaAs/GaAs quantum wells (QW) used in intraband-based quantum-well infrared photodetectors (QWIPs). LÄS MER