Search for dissertations about: "high-temperature superconductivity"

Showing result 6 - 10 of 38 swedish dissertations containing the words high-temperature superconductivity.

2. 6. Properties of small Bi2Sr2CaCu2O8 intrinsic Josephson junctions: confinement, flux-flow and resonant phenomena

   Author : Sven-Olof Katterwe; Vladimir M. Krasnov; Alexey Ustinov; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; high-temperature superconductivity; intrinsic Josephson junctions; tunneling; fluxons; flux-flow oscillator; THz-emission; cavity resonances; polaritons; micro nano-fabrication; fysik; Physics;

   Abstract : In this thesis, intrinsic Josephson junctions, naturally formed in the strongly anisotropic high-temperature superconductor Bi2Sr2CaCu2O8 (Bi-2212), are studied experimentally. For this purpose, small mesa structures are fabricated on the surface of single crystals using micro- and nano-fabrication tools, focused ion beam is used to reduce the area of the mesa-structures down to ≈ 1 × 1 μm2. READ MORE

4. 7. Optical Spectroscopy on Correlated Electron Materials

   Author : Johan Bielecki; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; dynamics; optical spectroscopy; colossal magnetoresistance; magnetism; transition metal oxides; high temperature superconductivity;

   Abstract : Strongly correlated materials poses a great challenge to our microscopic understanding of matter, mainly due to the inability of perturbative methods to predict the properties of such materials. This inability stems from strong correlations between electronic, lattice and spin degrees of freedom, leading to a variety of complex and exotic phenomena such as (unconventional) superconductivity, metal-insulator transitions, non-Fermi liquid behavior and colossal magnetoresistance. READ MORE

5. 8. High-frequency phenomena in small Bi2Sr2CaCu2O8+x intrinsic Josephson junctions

   Author : Holger Motzkau; Vladimir M. Krasnov; Reinhold Kleiner; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; high-temperature superconductivity; Bi-2212; cuprates; intrinsic Josephson junctions; intrinsic tunneling; fluxons; flux-flow oscillator; THz-emission; cavity resonances; polaritons; electrical doping; micro nano-fabrication; fysik; Physics;

   Abstract : In this thesis, the tunneling between individual atomic layers in structures of Bi2Sr2CaCu2O8+x based high-temperature superconductors are experimentally studied employing the intrinsic Josephson effect. A special attention is paid to the fabrication of small mesa structures using micro and nanofabrication techniques. READ MORE

6. 9. Structure and Dynamics in Transition Metal Perovskites — An Optical Spectroscopy Study

   Author : Johan Bielecki; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; multiferroics; colossal magnetoresistance; magnetism; proton-conduction; spin-state transition; structure; Ultrafast spectroscopy; high temperature superconductivity; dynamics; Raman;

   Abstract : Transition metal oxides with the perovskite structure exhibit a vast number of exotic properties due to the large number of competing degrees of freedom at the Fermi surface. Together with couplings between and correlations within these degrees of freedom, this class of materials is of high interest from both a practical and theoretical point of view. READ MORE

7. 10. Nanoscale YBa2Cu3O7-δ devices -Searching for a subdominant order parameter using a single electron transistor

   Author : David Gustafsson; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; grain boundary; Josephson junctions; YBCO; single electron transistors; high temperature superconductivity;

   Abstract : The microscopic origin of High critical Temperature Superconductivity (HTS) is still an open issue in condensed matter physics. It is believed that by exlporing the quasiparticle energy spectrum one can learn about the mechanism promoting the superconducting state. READ MORE