Sökning: "Cooper pair"

Visar resultat 21 - 25 av 26 avhandlingar innehållade orden Cooper pair.

1. 21. Parity Effects in Single Charge Tunneling

   Författare :Magnus Gisselfält; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; mesoscopic; single charge tunneling; photon-assisted tunneling; shot noise; SET transistor; parity effect; Andreev tunneling; Coulomb blockade;

   Sammanfattning : The subject of this thesis is single charge tunneling effects, especially parity effects, as they are manifested in quantum mechanical tunneling through a metallic island small enough to cause single electrons to block tunneling of other electrons due to Coulomb interaction. When the island is superconducting the ground state energy depends on the parity of the number of electrons on the island: outside of the condensate there will always be at least one electron contributing to the energy for an odd number of electrons and this will have observable consequences. LÄS MER

3. 22. Intrinsic tunneling spectroscopy of low-Tc cuprate superconductors : Pseudogap, fluctuations and electrical doping

   Författare :Thorsten Jacobs; Vladimir M. Krasnov; Magnus Andersson; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Bi-2201; Bi-2212; low-Tc; cuprates; intrinsic tunneling; transport measurements; pseudogap; fluctuations; electrical doping; Physics; fysik;

   Sammanfattning : In this thesis, intrinsic tunneling and magnetic transport measurements of the cuprate superconductor Bi2+xSr2-yCuO6+δ (Bi-2201) are presented. The compound is characterized by a single-CuO2 plane, has a very low critical temperature Tc ~ 4K and a relatively low upper critical field Hc2 ~ 10T. LÄS MER

4. 23. YBCO nanowires to study nanoscale ordering in High-Tc Superconductors

   Författare :Riccardo Arpaia; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; nanoscale ordering; nanoSQUIDs; nanowires; High-Tc superconductors; ultrathin films; oxygen doping; nanowire-based single photon detectors;

   Sammanfattning : We present the realization of YBa2Cu3O7-δ (YBCO) nanowires for both basic physics studies, which could help to elucidate the microscopic mechanisms of High critical Temperature Superconductors (HTS), and for novel applications.The first part of the thesis describes an improved nanopatterning procedure, based on e-beam lithography in combination with an amorphous carbon mask and a very gentle Ar+ ion etching. LÄS MER

5. 24. From Macroscopic to Microscopic Dynamics of Superconducting Cavities

   Författare :Anirban Bhattacharyya; Vitaliy Goryashko; Volker Ziemann; Roger Ruber; Jean Delayen; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; superconducting cavity; superconductivity; self-excited loop; Ginzburg-landau; vortex; optimization; quality factor; microwave; Fysik med inriktning mot elementarpartikelfysik; Physics with specialization in Elementary Particle Physics;

   Sammanfattning : Superconducting (SC) radio frequency (RF) cavities are at the heart of many large-scale particle accelerators such as the European Spallation Source (ESS), the X-ray Free Electron Laser (XFEL), the Linac Coherent Light Source (LCLS)-II and the proposed International Linear Collider (ILC). The SC cavities are essentially resonant structures with very high intrinsic quality factors (Q0) of the order of 1010. LÄS MER

7. 25. Structure and Dynamics in Transition Metal Perovskites — An Optical Spectroscopy Study

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

   Sammanfattning : 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. LÄS MER