Sökning: "Superconductivity"
Visar resultat 16 - 20 av 122 avhandlingar innehållade ordet Superconductivity.
16. Order in Strongly Correlated Quasi-One-Dimensional Systems : Solving Higher-Dimensional Systems Combining Matrix-Product-State Methods and Mean-Field Theory
Sammanfattning : Since their discovery the understanding of unconventional superconductors (USCs) has posed a great challenge in condensed matter physics. One central problem, both of theory and experiment, lies in determining the microscopic origin of electron pairing in such systems. LÄS MER
17. Deviations from the London model in superconductors
Sammanfattning : Using Small-Angle Neutron Scattering (SANS) we have studied the flux line lattices of the first heavy-fermion superconductor to be discovered, CeCu2Si2, the well-known high-temperature superconductor YBa2Cu3O7, along with Ca-doped variants of this compound, and several topological superconductor candidates that have attracted a lot of attention in the last few years, such as PbTaSe2, Au2Pb and β-Bi2Pd.Unconventional superconductors, with pairing mechanisms and properties that are not accounted for within BCS theory, are a subject of continuing interest. LÄS MER
18. Quantum Materials Probed by Light and Electron Spectroscopy
Sammanfattning : As new technologies rely heavily on materials’ properties, the quest for novel tunable electronic and magnetic materials occupies a large part of nowadays research efforts. Most promising materials are quantum materials, which exhibit a wide range of exotic electronic and magnetic phenomena and often show a great sensitivity to external perturbations such as temperature, pressure or chemical doping. LÄS MER
19. On the Finite Element Method for the Time-Dependent Ginzburg-Landau Equations
Sammanfattning : This thesis is primarily concerned with various issues regarding finite element approximation of the time-dependent Ginzburg-Landau equations. The time-dependent Ginzburg-Landau equations is a macroscopic, phenomenological model of superconductivity, consisting of a system of nonlinear, parabolic partial differential equations. LÄS MER
20. GaN-based HEMTs for Cryogenic Low-Noise Applications
Sammanfattning : Radio-astronomy deals with signals and radiations of extremely weak intensity. Also, it requires robust and rugged technologies able to sustain and prevent the Radio Frequency Interferences (RFI). LÄS MER